breeding method

peculiarities

examples of organisms

cell division in two

the body of the parent cell is divided by mitosis into two parts, each of which gives rise to full-fledged cells

prokaryotes, unicellular eukaryotes (amoeba)

multiple cell division

The body of the original cell divides mitotically into several parts, each of which becomes a new cell

Unicellular eukaryotes (flagellates, sporozoans)

budding

A tubercle containing a nucleus is first formed on the mother's cell. Kidney grows, reaches maternal size, detaches

Single-celled eukaryotes, some ciliates, yeast

sporulation

Spore is a special cell covered with a dense membrane that protects against external influences

Spore plants; some protozoa

vegetative reproduction:

An increase in the number of individuals of this species occurs by the separation of the viable parts of the vegetative body of the organism.

Plants, animals

In plants

Formation of buds, stem and root tubers, bulbs, rhizomes

Liliaceae, nightshade, gooseberry, etc.

In animals

Ordered and unordered division

Intestinal, starfish, annelids

peculiarities

prezygous

the formation of gametes (gametogenesis), the accumulation of ribosomal and messenger RNA, different parts of the cytoplasm acquire differences in chemical composition.

embryonic period

zygote (unicellular stage of development of a multicellular organism)

contains yolk grains, mitochondria, pigments, cytoplasm moves, pronounced bilateral symmetry (bilateral). A number of animal species begin to synthesize protein and new RNA

splitting up

cleavage grooves are formed, which divide the cell in half - into 2 blastomeres (2,4,8,16,32,64, etc.). As a result of a series of successive cleavages, a group of cells closely adjacent to each other is formed. The embryo resembles a raspberry berry. He received the name morula.

blastulation

the final stage of egg crushing. In the lancelet, blastula is formed when the embryo reaches 128 cells. Blastula has the shape of a bubble with a wall of one layer of cells called blastoderm.

gastrulation

complex movement of embryonic material with the formation of 2 or 3 layers of the body of the embryo (germ layers): ectoderm, endoderm and mesoderm. The development of sponges and coelenterates ends at the stage of two germ layers. All other organisms that are higher on the evolutionary ladder develop three germ layers.

histogenesis and organogenesis

the formation of tissues and organs occurs

causes of manifestation

meaning

Non-hereditary (modification variability)

a change in environmental conditions, as a result of which the organism changes within the normal range of the reaction given by the genotype

adaptation - adaptation to given environmental conditions, survival, preservation of offspring.

white cabbage in hot climates does not form a head of cabbage; breeds of horses and cows brought to the mountains become stunted

Hereditary (genotypic)

Mutational

the influence of external and internal mutagenic factors, resulting in a change in genes and chromosomes

material of natural and artificial selection, since mutations can be useful, harmful and indifferent, dominant and recessive

reproductive isolation> new species, genus> microevolution.

Combinative

occurs spontaneously within the population during crossing, when new combinations of genes appear in the offspring.

the spread of new hereditary changes that serve as material for selection.

the appearance of pink flowers when crossing white-flowered and red-flowered primroses.

Relative (correlative)

arises as a result of the properties of genes to influence the formation of not one, but two or more signs

constancy of interrelated signs, the integrity of the organism as a system

long-legged animals have a long neck.

aromorphosis

idioadaptation

general degeneration

hypergenesis

The emergence of electron transport chains (which provided the possibility of photosynthesis and aerobic respiration)

Galapagos finches (different types of beaks)

In bivalve molluscs, the disappearance of the head

The appearance of histone proteins and the nuclear envelope (which provided the possibility of mitosis, meiosis and sexual reproduction)

Dogs have non-retractable claws to speed up running, the presence of predatory teeth, a decrease in body temperature through increased mouth breathing (no sweat glands)

Pork tapeworm has a "loss" of the digestive system.

The emergence of germ layers in animals and differentiated tissues in plants (which led to the formation of organ systems).

In ladybirds, salamanders have a warning coloration.

Loss of vision in moles, proteus, deep-sea

The appearance of the axial skeleton - chord

Basic concepts and key terms: HUMAN BODY. Cell. Textile. Organs. Physiological systems. Regulation of human functions. Remember! What is an organism? What are the levels of organization of the animal organism?

Think!

“We live in a world in which people know much more about the internal structure of a car or about the operation of a laptop, touchscreen phone, than about their own body. But for each of us, it is vitally important to understand what our body is, how it is ordered and how it works, what supports it, and what unbalances it. Such "gaps in education" cost a person dearly and create problems with oneself, in communication with people and nature. " What are the features of the organization of the human body?

Why is the human body a biological system?

The modern scientific understanding of the organization of all living things is based on the structural-functional approach, according to which objects of living nature are biological systems. Structure and function are two interrelated manifestations of the existence of a biological system.

The human body is one of the most complex biosystems with the following levels of organization: molecular, cellular, tissue, organ, systemic. At each of these levels, coordinated processes occur that determine the integral existence of the organism.

The human body is an open system that is in a state of constant interaction (metabolism, energy and information) with the external environment. In this interaction, three fundamental properties are extremely important for the organism: self-regulation to maintain internal stability, self-renewal, that is, the formation of new molecules and structures, and self-reproduction to ensure continuity between parents and descendants.

So, the HUMAN ORGANISM is an integral open biological system, which is characterized by certain levels of organization, self-regulation, self-renewal and self-reproduction.

What are the levels of organization inherent in the human body?

Orderliness as a general property of living things has features inherent in each of the levels of organization of the human body.

Molecular level of organization. The components of this level are chemical elements and substances involved in biophysical processes and biochemical reactions. From over 100 known chemical elements about 90 is found in the human body. They are divided into groups: organogens (oxygen, hydrogen, carbon, nitrogen), macronutrients (for example, calcium, potassium, sodium, iron, phosphorus, chlorine) and trace elements (for example, cobalt, copper, zinc, iodine, fluorine, etc.) ... Highest content among inorganic compounds are water (about 60%) and mineral salts. Organic substances in the body contain carbohydrates, lipids, proteins, fats, nucleic acids, etc.

The cellular level of organization. The main parts of human cells, like plants, animals and fungi, are the surface apparatus, cytoplasm and nucleus. It is at this level that all the properties of life appear for the first time; therefore, the cell is the main structural and functional unit of the organism.

The tissue level of organization is formed by cells, which unite in groups to perform certain vital functions. Tissue is a collection of cells and intercellular substance, similar in origin, structural features and functions. In the human body, as well as in animals, there are 4 types of tissues - epithelial, connective, muscle and nervous.

The organ level of organization is determined by the orderliness of the structure and functions of organs. All 4 types of tissues are usually involved in the formation of an organ, but only one is decisive for its activity. For example, in bones such tissue is connective bone, in the heart - muscle. An organ is a part of the body

having a certain location, shape, structure and performing one or more specific functions. Most often, human organs are divided according to their functions into respiratory organs, digestive organs, etc.

The systemic level of organization is formed by specialized physiological systems of the body. Physiological system - a set of organs that are anatomically interconnected for the implementation of a physiological function. In the human body, the musculoskeletal, circulatory, respiratory, digestive, integumentary, urinary, reproductive, endocrine, nervous, sensory systems are isolated. The organs of various physiological systems are temporarily connected into functional systems to ensure the integral existence of the organism.

So, the HUMAN ORGANISM is an ordered level biosystem in which molecular, cellular, tissue, organ and systemic levels of organization are distinguished.

How is the integrity of the human body achieved?

Processes occurring at all levels of a person's organization are always consistent with each other. Such consistency and coordination occurs due to the processes of regulation of the functions of the human body.

Regulation of human functions is a set of processes that ensure a consistent and coordinated response of the body to changes in environmental conditions. These processes occur at the level of cells that generate signals. This is how neurons form electrical signals, gland cells produce substances that are chemical signals. These signals are transmitted throughout the body by nerve pathways or fluids of the internal environment (blood, tissue fluid and lymph). The mechanisms of nervous, humoral and immune regulation function in the human body.

Nervous regulation is the regulation of body functions by nerve impulses that are transmitted along nerve pathways and have a directed short-term effect.

Humoral regulation is regulation by means of chemical compounds that are carried in the body by fluids of the internal environment to provide a long-term and general effect on cells, tissues and organs.

Immune regulation is the regulation by means of chemical compounds and cells that are carried in the body by fluids of the internal environment to provide a protective effect on cells, tissues and organs.

These mechanisms of regulation of functions are closely interconnected. For example, humoral factors such as hormones (for example, adrenaline) affect the activity of the nervous system, and substances and cells of the immune system provide protection for the cells of the nervous system.

The regulation of the functions of the human body has features associated with more complex than in animals, social behavior, developed articulate speech, higher emotions, developed mental activity, etc.

So, the integrity and vital functions of the human body at different levels of its organization are provided by the interacting mechanisms of nervous, humoral and immune regulation of body functions.

ACTIVITY

Learning to cognize

Exercise 1. Consider Figure 2 and name the constituent and organelles of the cell. Remember what functions are performed by the indicated cell organelles.

Exercise 2. Look at picture 3, recognize the organs depicted on it. Fill in the table and draw a conclusion about the human body as a biological system.

LIFE FUNCTIONS OF THE HUMAN BODY

Biology + Philosophy

Philosophy (from the Greek. Love for wisdom, love for knowledge) is a science, the subject of which is a person's relationship with the outside world.

One of the functions of philosophy is to help a person in cognitive activity. The famous German philosopher GWF Hegel (1770-1831) noted that "parts and organs of a living body become simple components only at the hand of an anatomist." Explain this wise saying using knowledge about the human body as an integral biological system.

RESULT

This is tutorial material

The organism as a biological system

Reproduction of organisms, its meaning. Reproduction methods, similarities and differences between sexual and asexual reproduction. The use of sexual and asexual reproduction in human practice. The role of meiosis and fertilization in ensuring the constancy of the number of chromosomes in generations. The use of artificial insemination in plants and animals

Terms and concepts tested in examination paper: asexual reproduction, vegetative reproduction, hermaphroditism, zygote, ontogeny, fertilization, parthenogenesis, sexual reproduction, budding, spore.

Reproduction in the organic world. The ability to reproduce is one of the most important signs of life. This ability manifests itself already at the molecular level of life. Viruses, penetrating the cells of other organisms, reproduce their DNA or RNA and thus multiply. Reproduction- This is the reproduction of genetically similar individuals of a given species, ensuring the continuity and continuity of life.

The following forms of reproduction are distinguished:

Asexual reproduction. This form of reproduction is typical for both unicellular and multicellular organisms. However, asexual reproduction is most common in the kingdoms of Bacteria, Plants, and Fungi. In the kingdom Among animals, in this way, mainly protozoa and coelenterates reproduce.

There are several ways of asexual reproduction:

- Simple division of the mother cell into two or more cells. This is how all bacteria and protozoa multiply.

- Vegetative reproduction by body parts is typical for multicellular organisms - plants, sponges, coelenterates, and some worms. Plants can vegetatively reproduce by cuttings, layering, root suckers and other parts of the body.

- Budding - one of the variants of vegetative reproduction is characteristic of yeast and coelenterates multicellular animals.

- Mitotic sporulation is common among bacteria, algae, and some protozoa.

Asexual reproduction usually provides an increase in the number of genetically homogeneous offspring, therefore it is often used by plant breeders to conserve useful properties varieties.

Sexual reproduction- a process in which genetic information from two individuals is combined. The combination of genetic information can occur when conjugation (temporary connection of individuals for the exchange of information, as is the case with ciliates) and copulation (fusion of individuals for fertilization) in unicellular animals, as well as during fertilization in representatives of different kingdoms. A special case of sexual reproduction is parthenogenesis in some animals (aphids, bee drones). In this case, a new organism develops from an unfertilized egg, but before that, gametes are always formed.

Sexual reproduction in angiosperms occurs by double fertilization. The fact is that haploid pollen grains are formed in the anther of the flower. The kernels of these grains are divided into two - generative and vegetative. Once on the stigma of the pistil, the pollen grain germinates, forming a pollen tube. The generative nucleus divides once more to form two sperm. One of them, penetrating into the ovary, fertilizes the egg, and the other fuses with the two polar nuclei of the two central cells of the embryo, forming a triploid endosperm.

During sexual reproduction, individuals of different sexes form gametes. Females produce eggs, males produce sperm, and bisexuals (hermaphrodites) produce both eggs and sperm. In most algae, two identical reproductive cells merge. With the fusion of haploid gametes, fertilization and the formation of a diploid zygote occur. The zygote develops into a new individual.

All of the above is true only for eukaryotes. Prokaryotes also have sexual reproduction, but it happens in a different way.

Thus, during sexual reproduction, the genomes of two different individuals of the same species are mixed. The offspring carry new genetic combinations that distinguish them from their parents and from each other. Various combinations of genes, which appear in the offspring in the form of new traits of interest to humans, are selected by breeders for breeding new breeds of animals or plant varieties. In some cases, apply artificial insemination... This is done both in order to get offspring with the desired properties, and in order to overcome the childlessness of some women.

EXAMPLES OF TASKS

Part A

A1. The fundamental differences between sexual and asexual reproduction are that sexual reproduction:

1) occurs only in higher organisms

2) it is an adaptation to unfavorable environmental conditions

3) provides combinative variability of organisms

4) provides genetic consistency of the species

A2. How many spermatozoa are formed as a result of spermatogenesis from two primary germ cells?

1) eight 2) two 3) six 4) four

A3. The difference between ovogenesis and spermatogenesis is that:

1) in oogenesis, four equivalent gametes are formed, and in spermatogenesis, one

2) eggs contain more chromosomes than sperm

3) in ovogenesis, one full-fledged gamete is formed, and in spermatogenesis - four

4) ovogenesis takes place with one division of the primary reproductive cell, and spermatogenesis - with two

A4. How many divisions of the original cell occur during gametogenesis

1) 2 2) 1 3) 3 4) 4

A5. The number of germ cells formed in the body, most likely, may depend on

1) stock nutrients in a cage

2) the age of the individual

3) the ratio of males and females in the population

4) the likelihood of gametes meeting each other

A6. Asexual reproduction dominates the life cycle

1) hydras 3) sharks

A7. Ferns' gametes are formed

1) in sporangia 3) on leaves

2) in the bud 4) in disputes

A8. If the diploid set of chromosomes of bees is 32, then 16 chromosomes will be contained in somatic cells

1) the queen bee

2) a working bee

3) drones

4) all listed individuals

A9. Endosperm in flowering plants is formed by fusion

1) sperm and eggs

2) two sperm and an egg

3) polar nucleus and sperm

4) two polar nuclei and sperm

A10. Double fertilization occurs in

1) moss cuckoo flax 3) chamomile officinalis

2) bracken fern 4) Scots pine

Part B

IN 1. Choose the correct statements

1) The formation of gametes in plants and animals occurs according to the same mechanism

2) All types of animals have eggs of the same size

3) Fern spores are formed as a result of meiosis

4) 4 eggs are formed from one oocyte

5) The egg cell of angiosperms is fertilized by two sperm

6) The endosperm of angiosperms is triploid.

IN 2. Establish a correspondence between breeding forms and their signs

OT. Establish the correct sequence for the double fertilization of flowering plants.

A) fertilization of the egg and central cell

B) the formation of a pollen tube

B) pollination

D) the formation of two sperm

E) development of the embryo and endosperm

Part C

C1. Why is the endosperm of angiosperms triploid, while the rest of the cells are diploid?

C2. Find errors in the text provided, indicate the numbers of the sentences in which they are allowed, and correct them. 1) In the anthers of angiosperms, diploid pollen grains are formed. 2) The kernel of the pollen grain is divided into two nuclei: vegetative and generative. 3) A grain of pollen falls on the stigma of the pistil and grows towards the ovary. 4) In the pollen tube, two sperm are formed from the vegetative nucleus. 5) One of them merges with the nucleus of the egg, forming a triploid zygote. 6) Other sperm fuses with the nuclei of the central cells, forming the endosperm.

Ontogenesis and its inherent patterns. Specialization of cells, formation of tissues, organs. Embryonic and postembryonic development of organisms. Life cycles and alternation of generations. Causes of developmental disorders of organisms

Ontogenesis. Ontogenesis - This is the individual development of the organism from the moment of the formation of the zygote to death. In the course of ontogenesis, a regular change in phenotypes characteristic of a given species is manifested. Distinguish indirect and straight ontogeny. Indirect development(metamorphosis) occurs in flatworms, molluscs, insects, fish, amphibians. Their embryos go through several stages in their development, including the larval stage. Direct development passes in non-larval or intrauterine form. It includes all forms of ovoviviparity, the development of embryos of reptiles, birds and oviparous mammals, as well as the development of some invertebrates (orthoptera, arachnids, etc.). Intrauterine development occurs in mammals, including humans. V ontogenesis there are two periods - embryonic - from the formation of the zygote to the exit from the egg membranes and postembryonic - from the moment of birth to death. The embryonic period a multicellular organism consists of the following stages: zygotes; blastula- stages of development of a multicellular embryo after cleavage of the zygote. The zygote in the process of blastulation does not increase in size, the number of cells of which it consists increases; stages of formation of a single-layer embryo covered blastoderm, and the formation of the primary body cavity - blastocoels ; gastrula- the stages of formation of germ layers - ectoderm, endoderm (in two-layer coelenterates and sponges) and mesoderm (in three-layer ones in other multicellular animals). In coelenterates, specialized cells are formed at this stage, such as stinging, reproductive, skin-muscular, etc. The process of gastrula formation is called gastrulation .

Neirula- the stages of the laying of individual organs.

Histo- and organogenesis- the stages of the appearance of specific functional, morphological and biochemical differences between individual cells and parts of the developing embryo. In vertebrates, organogenesis can be distinguished:

a) neurogenesis - the process of formation of the neural tube (brain and spinal cord) from the ectodermal germ layer, as well as skin, organs of sight and hearing;

b) chordogenesis - the process of formation from mesoderm chord, muscles, kidneys, skeleton, blood vessels;

c) the process of forming from endoderm intestines and related organs - liver, pancreas, lungs. The consistent development of tissues and organs, their differentiation occurs due to embryonic induction- the influence of some parts of the embryo on the development of other parts. This is due to the activity of proteins that are included in the work at certain stages of the development of the embryo. Proteins regulate the activity of genes that determine the characteristics of an organism. Thus, it becomes clear why the signs of a certain organism appear gradually. All genes never come into play together. At a particular time, only part of the genes are working.

Postembryonic period is divided into the following stages:

- postembryonic (before puberty);

- the period of puberty (implementation of reproductive functions);

- aging and death.

In humans, the initial stage of the postembryonic period is characterized by intensive growth of organs and body parts in accordance with the established proportions. In general, the postembryonic period of a person is divided into the following periods:

- infant (from birth to 4 weeks);

- chest (from 4 weeks to a year);

- preschool (nursery, middle, senior);

- school (early, teenage);

- reproductive (young up to 45 years old, mature up to 65 years old);

- post-reproductive (elderly up to 75 years old and senile - after 75 years).

EXAMPLES OF TASKS

Part A

A1. The two-layer structure flowed is characteristic of

1) annelids 3) coelenterates

2) insects 4) protozoa

A2. There is no mesoderm

1) earthworm 3) coral polyp

A3. Direct development occurs in

1) frogs 2) locusts 3) flies 4) bees

A4. As a result of crushing the zygote,

1) gastrula 3) neurula

2) blastula 4) mesoderm

A5. From endoderm develops

1) aorta 2) brain 3) lungs 4) skin

A6. Individual organs of a multicellular organism are laid at the stage

1) blastula 3) fertilization

2) gastrula 4) neurula

A7. Blastulation is

1) cell growth

2) multiple crushing of the zygote

3) cell division

4) an increase in the size of the zygote

A8. The gastrula of a dog's embryo is:

1) an embryo with a formed neural tube

2) multicellular single-layer embryo with a body cavity

3) multicellular three-layer embryo with a body cavity

4) multicellular two-layer embryo

A9. Differentiation of cells, organs and tissues occurs as a result

1) the action of certain genes at a certain time

2) the simultaneous action of all genes

3) gastrulation and blastulation

4) development of certain organs

A10.What stage of embryonic development of vertebrates is represented by a multitude of non-specialized cells?

1) blastula 3) early neurula

2) gastrula 4) late neurula

Part B

IN 1. Which of the following is related to embryogenesis?

1) fertilization 4) spermatogenesis

2) gastrulation 5) crushing

3) neurogenesis 6) ovogenesis

IN 2. Select the signs that are characteristic of blastula

1) an embryo in which a notochord is formed

2) multicellular embryo with a body cavity

3) an embryo consisting of 32 cells

4) three-layer embryo

5) a single-layer embryo with a body cavity

6) an embryo consisting of one layer of cells

OT. Relate the organs of the multicellular embryo to the germ layers from which these organs are laid

Part C

C1. Give examples of direct and indirect postembryonic development using insects as an example.

The organism as a biological system

3.2. Reproduction of organisms, its meaning. Reproduction methods, similarities and differences between sexual and asexual reproduction. The use of sexual and asexual reproduction in human practice. The role of meiosis and fertilization in ensuring the constancy of the number of chromosomes in generations. The use of artificial insemination in plants and animals

asexual reproduction, vegetative reproduction, hermaphroditism, zygote, ontogeny, fertilization, parthenogenesis, sexual reproduction, budding, spore.

Reproduction in the organic world. The ability to reproduce is one of the most important signs of life. This ability manifests itself already at the molecular level of life. Viruses, penetrating the cells of other organisms, reproduce their DNA or RNA and thus multiply. Reproduction- This is the reproduction of genetically similar individuals of a given species, ensuring the continuity and continuity of life.

The following forms of reproduction are distinguished:

Asexual reproduction. This form of reproduction is typical for both unicellular and multicellular organisms. However, asexual reproduction is most common in the kingdoms of Bacteria, Plants, and Fungi. In the kingdom Among animals, in this way, mainly protozoa and coelenterates reproduce.

There are several ways of asexual reproduction:

- Simple division of the mother cell into two or more cells. This is how all bacteria and protozoa multiply.

- Vegetative reproduction by body parts is typical for multicellular organisms - plants, sponges, coelenterates, and some worms. Plants can vegetatively reproduce by cuttings, layering, root suckers and other parts of the body.

- Budding - one of the variants of vegetative reproduction is characteristic of yeast and coelenterates multicellular animals.

- Mitotic sporulation is common among bacteria, algae, and some protozoa.

Asexual reproduction usually provides an increase in the number of genetically homogeneous offspring, therefore it is often used by plant breeders to preserve the beneficial properties of the variety.

Sexual reproduction - a process in which genetic information from two individuals is combined. The combination of genetic information can occur when conjugation (temporary connection of individuals for the exchange of information, as is the case with ciliates) and copulation (fusion of individuals for fertilization) in unicellular animals, as well as during fertilization in representatives of different kingdoms. A special case of sexual reproduction is parthenogenesis in some animals (aphids, bee drones). In this case, a new organism develops from an unfertilized egg, but before that, gametes are always formed.

Sexual reproduction in angiosperms occurs by double fertilization. The fact is that haploid pollen grains are formed in the anther of the flower. The kernels of these grains are divided into two - generative and vegetative. Once on the stigma of the pistil, the pollen grain germinates, forming a pollen tube. The generative nucleus divides once more to form two sperm. One of them, penetrating into the ovary, fertilizes the egg, and the other fuses with the two polar nuclei of the two central cells of the embryo, forming a triploid endosperm.

During sexual reproduction, individuals of different sexes form gametes. Females produce eggs, males produce sperm, and bisexuals (hermaphrodites) produce both eggs and sperm. In most algae, two identical reproductive cells merge. With the fusion of haploid gametes, fertilization and the formation of a diploid zygote occur. The zygote develops into a new individual.

All of the above is true only for eukaryotes. Prokaryotes also have sexual reproduction, but it happens in a different way.

Thus, during sexual reproduction, the genomes of two different individuals of the same species are mixed. The offspring carry new genetic combinations that distinguish them from their parents and from each other. Various combinations of genes, which appear in the offspring in the form of new traits of interest to humans, are selected by breeders for breeding new breeds of animals or plant varieties. In some cases, artificial insemination is used. This is done both in order to get offspring with the desired properties, and in order to overcome the childlessness of some women.

A1. The fundamental differences between sexual and asexual reproduction are that sexual reproduction:

1) occurs only in higher organisms

2) it is an adaptation to unfavorable environmental conditions

3) provides combinative variability of organisms

4) provides genetic consistency of the species

A2. How many spermatozoa are formed as a result of spermatogenesis from two primary germ cells?

1) eight 2) two 3) six 4) four

A3. The difference between ovogenesis and spermatogenesis is that:

1) in oogenesis, four equivalent gametes are formed, and in spermatogenesis, one

2) eggs contain more chromosomes than sperm

3) in ovogenesis, one full-fledged gamete is formed, and in spermatogenesis - four

4) ovogenesis takes place with one division of the primary reproductive cell, and spermatogenesis - with two

A4. How many divisions of the original cell occur during gametogenesis

1) 2 2) 1 3) 3 4) 4

A5. The number of germ cells formed in the body, most likely, may depend on

1) supply of nutrients in the cell

2) the age of the individual

3) the ratio of males and females in the population

4) the likelihood of gametes meeting each other

A6. Asexual reproduction dominates the life cycle

1) hydras 3) sharks

A7. Ferns' gametes are formed

1) in sporangia 3) on leaves

2) in the bud 4) in disputes

A8. If the diploid set of chromosomes of bees is 32, then 16 chromosomes will be contained in somatic cells

1) the queen bee

2) a working bee

3) drones

4) all listed individuals

A9. Endosperm in flowering plants is formed by fusion

1) sperm and eggs

2) two sperm and an egg

3) polar nucleus and sperm

4) two polar nuclei and sperm

A10. Double fertilization occurs in

1) moss cuckoo flax 3) chamomile officinalis

2) bracken fern 4) Scots pine

IN 1. Choose the correct statements

1) The formation of gametes in plants and animals occurs according to the same mechanism

2) All types of animals have eggs of the same size

3) Fern spores are formed as a result of meiosis

4) 4 eggs are formed from one oocyte

5) The egg cell of angiosperms is fertilized by two sperm

6) The endosperm of angiosperms is triploid.

IN 2. Establish a correspondence between breeding forms and their signs

OT. Establish the correct sequence for the double fertilization of flowering plants.

A) fertilization of the egg and central cell

B) the formation of a pollen tube

B) pollination

D) the formation of two sperm

E) development of the embryo and endosperm

C1. Why is the endosperm of angiosperms triploid, while the rest of the cells are diploid?

C2. Find errors in the text provided, indicate the numbers of the sentences in which they are allowed, and correct them. 1) In the anthers of angiosperms, diploid pollen grains are formed. 2) The kernel of the pollen grain is divided into two nuclei: vegetative and generative. 3) A grain of pollen falls on the stigma of the pistil and grows towards the ovary. 4) In the pollen tube, two sperm are formed from the vegetative nucleus. 5) One of them merges with the nucleus of the egg, forming a triploid zygote. 6) Other sperm fuses with the nuclei of the central cells, forming the endosperm.

Ontogenesis. Ontogenesis - This is the individual development of the organism from the moment of the formation of the zygote to death. In the course of ontogenesis, a regular change in phenotypes characteristic of a given species is manifested. Distinguish indirect and straight ontogeny. Indirect development(metamorphosis) occurs in flatworms, molluscs, insects, fish, amphibians. Their embryos go through several stages in their development, including the larval stage. Direct development passes in non-larval or intrauterine form. It includes all forms of ovoviviparity, the development of embryos of reptiles, birds and oviparous mammals, as well as the development of some invertebrates (orthoptera, arachnids, etc.). Intrauterine development occurs in mammals, including humans. V ontogenesis there are two periods - embryonic - from the formation of the zygote to the exit from the egg membranes and postembryonic - from the moment of birth to death. The embryonic period a multicellular organism consists of the following stages: zygotes; blastula- stages of development of a multicellular embryo after cleavage of the zygote. The zygote in the process of blastulation does not increase in size, the number of cells of which it consists increases; stages of formation of a single-layer embryo covered blastoderm, and the formation of the primary body cavity - blastocoels; gastrula- the stages of formation of germ layers - ectoderm, endoderm (in two-layer coelenterates and sponges) and mesoderm (in three-layer ones in other multicellular animals). In coelenterates, specialized cells are formed at this stage, such as stinging, reproductive, skin-muscular, etc. The process of gastrula formation is called gastrulation.

Neirula- the stages of the laying of individual organs.

Histo- and organogenesis- the stages of the appearance of specific functional, morphological and biochemical differences between individual cells and parts of the developing embryo. In vertebrates, organogenesis can be distinguished:

a) neurogenesis - the process of formation of the neural tube (brain and spinal cord) from the ectodermal germ layer, as well as the skin, organs of vision and hearing;

b) chordogenesis - the process of formation from mesoderm chord, muscles, kidneys, skeleton, blood vessels;

c) the process of forming from endoderm intestines and related organs - liver, pancreas, lungs. The consistent development of tissues and organs, their differentiation occurs due to embryonic induction- the influence of some parts of the embryo on the development of other parts. This is due to the activity of proteins that are included in the work at certain stages of the development of the embryo. Proteins regulate the activity of genes that determine the characteristics of an organism. Thus, it becomes clear why the signs of a certain organism appear gradually. All genes never come into play together. At a particular time, only part of the genes are working.

Postembryonic period is divided into the following stages:

- postembryonic (before puberty);

- the period of puberty (implementation of reproductive functions);

- aging and death.

In humans, the initial stage of the postembryonic period is characterized by intensive growth of organs and body parts in accordance with the established proportions. In general, the postembryonic period of a person is divided into the following periods:

- infant (from birth to 4 weeks);

- chest (from 4 weeks to a year);

- preschool (nursery, middle, senior);

- school (early, teenage);

- reproductive (young up to 45 years old, mature up to 65 years old);

- post-reproductive (elderly up to 75 years old and senile - after 75 years).

A1. The two-layer structure flowed is characteristic of

1) annelids 3) coelenterates

2) insects 4) protozoa

A2. There is no mesoderm

1) earthworm 3) coral polyp

A3. Direct development occurs in

1) frogs 2) locusts 3) flies 4) bees

A4. As a result of crushing the zygote,

1) gastrula 3) neurula

2) blastula 4) mesoderm

A5. From endoderm develops

1) aorta 2) brain 3) lungs 4) skin

A6. Individual organs of a multicellular organism are laid at the stage

1) blastula 3) fertilization

2) gastrula 4) neurula

A7. Blastulation is

1) cell growth

2) multiple crushing of the zygote

3) cell division

4) an increase in the size of the zygote

A8. The gastrula of a dog's embryo is:

1) an embryo with a formed neural tube

2) multicellular single-layer embryo with a body cavity

3) multicellular three-layer embryo with a body cavity

4) multicellular two-layer embryo

A9. Differentiation of cells, organs and tissues occurs as a result

1) the action of certain genes at a certain time

2) the simultaneous action of all genes

3) gastrulation and blastulation

4) development of certain organs

A10. What stage of the embryonic development of vertebrates is represented by a multitude of non-specialized cells?

1) blastula 3) early neurula

2) gastrula 4) late neurula

IN 1. Which of the following is related to embryogenesis?

1) fertilization 4) spermatogenesis

2) gastrulation 5) crushing

3) neurogenesis 6) ovogenesis

IN 2. Select the signs that are characteristic of blastula

1) an embryo in which a notochord is formed

2) multicellular embryo with a body cavity

3) an embryo consisting of 32 cells

4) three-layer embryo

5) a single-layer embryo with a body cavity

6) an embryo consisting of one layer of cells

OT. Relate the organs of the multicellular embryo to the germ layers from which these organs are laid

C1. Give examples of direct and indirect postembryonic development using insects as an example.

allelic genes, analyzing crossing, gene interaction, gene, genotype, heterozygosity, hypothesis of gamete purity, homozygosity, dihybrid crossing, G. Mendel's laws, quantitative traits, crossing over, flew, multiple alleles, monohybrid cross, independent inheritance, incomplete dominance, the rule of uniformity, splitting, phenotype, cytological bases of Mendel's laws.

Genetics- the science of heredity and variability of organisms. These two properties are inextricably linked with each other, although they have opposite directions. Heredity presupposes the preservation of information, and variability changes this information. Heredity- this is the property of an organism to repeat its signs and features of its development in a number of generations. Variability is the property of organisms to change their characteristics under the influence of the external or internal environment, as well as as a result of new genetic combinations that arise during sexual reproduction. The role of variability is that it "supplies" new genetic combinations that are subject to natural selection, and heredity preserves these combinations.

The main genetic concepts include the following:

Gene- a section of a DNA molecule in which information about the amino acid sequence in one protein molecule is encoded.

Allele- a pair of genes responsible for an alternative (different) manifestation of the same trait. For example, two allelic genes located at the same loci (places) of homologous chromosomes are responsible for eye color. Only one of them can be responsible for the development of brown laz, and the other for the development blue eyes... In the case when both genes are responsible for the same development of a trait, they speak of homozygous the body on this basis. If allelic genes determine the different development of a trait, they talk about heterozygous the body.

Allelic genes can be dominant suppressing the alternative gene, and recessive suppressed.

The set of genes in an organism is called genotype of a given organism. The genotype of an organism is described by the words “homozygous” or “heterozygous”. However, not all genes show up. The aggregate external signs an organism is called its phenotype. Brown-eyed, full, tall is a way of describing the phenotype of an organism. They also speak of a dominant or recessive phenotype.

Genetics studies the patterns of inheritance of traits. The main method of genetics is the hybridological method or crossbreeding. This method was developed by the Austrian scientist Gregor Mendel in 1865.

The development of genetics has entailed the development of many scientific areas and, first of all, evolutionary doctrine, plant and animal breeding, medicine, biotechnology, pharmacology, etc.

At the turn of the 20th and 21st centuries, the human genome was deciphered. Scientists were amazed that we have only 35,000 genes, and not 100,000 as previously thought. The roundworm has 19 thousand genes, the mustard - 25 thousand. The differences between humans and chimpanzees are 1% of genes, and with mice - 10%. Man inherited genes that are 3 billion years old and relatively young genes.

What does reading the genome give to science? First of all, this knowledge makes it possible to purposefully conduct genetic research to identify both pathological and necessary useful genes. Scientists do not give up hope for curing people from diseases such as cancer and AIDS, diabetes, etc. They also do not leave hope for overcoming decrepit old age, premature mortality and many other troubles of mankind.

3.5. Regularities of heredity, their cytological foundations. Mono- and dihybrid crossing. The laws of inheritance established by G. Mendel. Linked inheritance of traits, gene linkage disorder. T. Morgan's laws. Chromosomal theory of heredity. Genetics of sex. Inheritance of sex-linked traits. Genotype as integral system... Development of knowledge about the genotype. The human genome. Interaction of genes. Solving genetic problems. Drawing up crossing schemes. G. Mendel's laws and their cytological foundations

Terms and concepts tested in the examination paper: allelic genes, analyzing crossing, gene, genotype, heterozygosity, gamete purity hypothesis, homozygosity, dihybrid crossing, Mendel's laws, monohybrid crossing, morganida, heredity, independent inheritance, incomplete dominance, uniformity rule, cleavage, phenotype, chromosomal basis theory Mendel's laws.

The success of Gregor Mendel's work was due to the fact that he correctly chose the object of research and followed the principles that became the basis of the hybridological method:

1. The object of the study was pea plants belonging to the same species.

2. Experimental plants clearly differed in their characteristics - tall - low, with yellow and green seeds, with smooth and wrinkled seeds.

3. The first generation from the original parental forms has always been the same. Tall parents gave tall offspring, short parents gave small plants. Thus, the original varieties were the so-called "clean lines".

4. G. Mendel kept a quantitative account of the descendants of the second and subsequent generations, in which splitting in characters was observed.

G. Mendel's laws describe the nature of inheritance of individual traits over several generations.

Mendel's first law or uniformity rule. The law is derived on the basis of statistical data obtained by G. Mendel when crossing different varieties peas that had clear alternative differences in the following characteristics:

- seed shape (round / non-round);

- seed color (yellow / green);

- seed skin (smooth / wrinkled), etc.

When crossing plants with yellow and green seeds, Mendel found that all hybrids of the first generation ended up with yellow seeds. He called this feature dominant. The trait that determines the green color of the seeds was called recessive (receding, suppressed).

Since the examination work requires students to correctly draw up notes when solving genetic problems, we will show an example of such a record.

1. Based on the results obtained and their analysis, Mendel formulated his first law... When crossing homozygous individuals that differ in one or more pairs of alternative traits, all hybrids of the first generation will be uniform in these traits and similar to the parent with a dominant trait.

When incomplete dominance only 25% of individuals are phenotypically similar to a parent with a dominant trait and 25% of individuals will be similar to a phenotypically recessive parent. The remaining 50% of heterozygotes will be phenotypically different from them. For example, from red-flowered and white-flowered snapdragon plants in the offspring, 25% of individuals are red, 25% are white, and 50% are pink.

2. To identify the heterozygosity of an individual for a specific allele, i.e. the presence of a recessive gene in the genotype, is used analyzing cross... For this, an individual with a dominant trait (AA? Or Aa?) Is crossed with an individual homozygous for the recessive allele. In the case of heterozygosity of an individual with a dominant trait, the splitting in the offspring will be 1: 1

AA? aa> 100% Aa

Huh? aa> 50% Aa and 50% aa

Mendel's second law or the law of splitting. When crossing heterozygous hybrids of the first generation with each other, in the second generation splitting is found according to this trait. This splitting has a natural statistical character: 3: 1 by phenotype and 1: 2: 1 by genotype. In the case of crossing forms with yellow and green seeds in accordance with Mendel's second law, the following crossing results are obtained.

Seeds appear with both yellow and green color.

Mendel's third law or the law of independent inheritance in dihybrid (polyhybrid) crossing. This law is derived from the analysis of the results obtained by crossing individuals that differ in two pairs of alternative traits. For example: a plant that gives yellow, smooth the seeds are crossed with a plant that produces green, wrinkled seeds.

For further recording, the Punnett grating is used:

In the second generation, 4 phenotypes may appear with a ratio of 9: 3: 3: 1 and 9 genotypes.

As a result of the analysis, it turned out that the genes of different allelic pairs and the corresponding traits are transmitted independently of each other. This law is true:

- for diploid organisms;

- for genes located in different homologous chromosomes;

- with an independent divergence of homologous chromosomes in meiosis and their random combination during fertilization.

These conditions are the cytological basis of dihybrid crossing.

The same patterns apply to polyhybrid crosses.

In Mendel's experiments, the discreteness (discontinuity) of hereditary material was established, which later led to the discovery of genes as elementary material carriers of hereditary information.

In accordance with the hypothesis of gamete purity, only one of the homologous chromosomes of a given pair is normally found in a sperm or egg cell. That is why, during fertilization, the diploid set of chromosomes of a given organism is restored. Split Is the result of a random combination of gametes carrying different alleles.

Since the events are random, the pattern is statistical in nature, i.e. is determined by a large number of equally probable events - encounters of gametes carrying different (or identical) alternative genes.

A1. The dominant allele is

1) a pair of genes of the same expression

2) one of two allelic genes

3) a gene that suppresses the action of another gene

4) suppressed gene

A2. A part of a DNA molecule is considered a genome if it encodes information about

1) several signs of an organism

2) one sign of the body

3) multiple proteins

4) t-RNA molecule

A3. If the trait does not appear in the first generation hybrids, then it is called

1) alternative

2) dominant

3) not completely dominant

4) recessive

A4. Allelic genes are located in

1) identical parts of homologous chromosomes

2) different parts of homologous chromosomes

3) identical sections of non-homologous chromosomes

4) different parts of non-homologous chromosomes

A5. Which entry reflects a diheterozygous organism:

1) ААВВ 2) АаВВ 3) АаВвСс 4) ааВВСС

A6. Determine the phenotype of a pumpkin with genotype Cc BB, knowing that the white color dominates over the yellow, and the disc-shaped shape of the fruit - over the globular

1) white, spherical 3) yellow disc-shaped

2) yellow, spherical 4) white, disc-shaped

A7. What offspring will be obtained by crossing a hornless (hornless) homozygous cow (the hornless gene B dominates) with a horned bull.

3) 50% BB and 50% BB

4) 75% BB and 25% BB

A8. In humans, the gene for lop-eared (A) dominates over the gene for normally pressed ears, and the gene for non-red hair (B) over the gene for red hair. What is the genotype of a lop-eared, red-haired father if, in a marriage with a non-red-haired woman with normally pressed ears, he had only lop-eared, non-red children?

1) ААвв 2) АаВв 3) ааВВ 4) ААвВ

A9. What is the probability of the birth of a blue-eyed (a), fair-haired (c) child from the marriage of a blue-eyed dark-haired (B) father and a brown-eyed (A), fair-haired mother, heterozygous for dominant characteristics?

1) 25% 2) 75% 3) 12,5% 4) 50%

A10. Mendel's second law is a law that describes the process

1) gene linkage

2) the mutual influence of genes

3) splitting signs

4) independent distribution of gametes

A11. How many types of gametes does an organism with the AAVvCc genotype form?

1) one 2) two 3) three 4) four

C1. Determine the possible genotypes of the parents and five children, among whom were children with Roman and straight noses, full and thin lips if it is known that a man with a Roman nose and thin lips married a girl with also a Roman nose and full lips. Prove your answer by writing the solution to the problem in the form of two crossing schemes. How many crossing patterns can be analyzed to solve this problem?

Chromosomal theory of heredity. The founder of the chromosome theory Thomas Gent Morgan, American geneticist, Nobel laureate. Morgan and his students found that:

- each gene has a specific chromosome locus(a place);

- genes on the chromosome are located in a certain sequence;

- the most closely located genes of one chromosome are linked, therefore they are inherited mainly together;

- groups of genes located on the same chromosome form linkage groups;

- the number of clutch groups is haploid the set of chromosomes homogametic individuals and n + 1 in heterogametic individuals;

- between homologous chromosomes, there can be an exchange of regions ( crossing over); as a result of crossing over, gametes appear, the chromosomes of which contain new combinations of genes;

- the frequency (in%) of crossing over between non-allelic genes is proportional to the distance between them;

- a set of chromosomes in cells of this type ( karyotype) is an characteristic feature species;

- the frequency of crossing over between homologous chromosomes depends on the distance between genes located on the same chromosome. The greater this distance, the higher the crossover frequency. 1 morganida (1% crossing over) or the percentage of occurrence of crossover individuals is taken as a unit of distance between genes. With a value of 10 morganids, it can be argued that the frequency of crossing chromosomes at the points of location of these genes is 10% and that new genetic combinations will be identified in 10% of the offspring.

To clarify the nature of the location of genes in chromosomes and determine the frequency of crossing over between them, genetic maps are built. The map reflects the order of the genes in a chromosome and the distance between genes of one chromosome. These conclusions of Morgan and his collaborators are called the chromosomal theory of heredity. The most important consequences of this theory are modern ideas about the gene as a functional unit of heredity, its divisibility and ability to interact with other genes.

Tasks illustrating the chromosomal theory are quite complex and cumbersome to record, therefore, in the examination works of the exam assignments for gender-linked inheritance are given.

Genetics of sex. Gender-linked inheritance. Chromosome sets of different sexes differ in the structure of sex chromosomes. The male Y chromosome does not contain many of the alleles found on the X chromosome. Traits determined by the genes of the sex chromosomes are called sex-linked. The nature of inheritance depends on the distribution of chromosomes in meiosis. In heterogametic sexes, traits linked to the X chromosome and having no allele in the Y chromosome appear even when the gene that determines the development of these traits is recessive. In humans, the Y chromosome is passed from father to sons, and the X chromosome to daughters. Children receive the second chromosome from their mother. It is always the X chromosome. If the mother carries a pathological recessive gene on one of the X chromosomes (for example, a gene for color blindness or hemophilia), but she is not sick herself, then she is a carrier. If this gene is passed on to their sons, they may become sick with this disease, because there is no allele in the Y chromosome that suppresses the pathological gene. The sex of the organism is determined at the time of fertilization and depends on the chromosome set of the formed zygote. In birds, females are heterogametic, and males are homogametic.

An example of gender-linked inheritance. It is known that in humans there are several traits linked to the X chromosome. One of these signs is the absence of sweat glands. This is a recessive trait, if the X chromosome carrying the gene that determines it gets to the boy, then this trait will certainly appear in him. If you read the famous novel by Patrick Suskind "Perfume", then you will remember that it was about a baby who had no smell.

Consider an example of gender-linked inheritance. The mother has sweat glands, but she is a carrier of the recessive trait - Xp X, the father is healthy - XY. Mother's gametes - Xp, X. Father's gametes - X, U.

From this marriage, children with the following genotypes and phenotypes can be born:

Genotype as an integral, historically developed system. The term genotype was proposed in 1909 by the Danish geneticist Wilhelm Johansen. He also introduced the terms: gene, allele, phenotype, line, pure line, population.

Genotype Is a set of genes of a given organism. According to the latest data, humans have about 35 thousand genes.

The genotype, as a single functional system of the organism, has developed in the process of evolution. A sign of the systemic genotype is gene interaction .

Allelic genes (more precisely, their products - proteins) can interact with each other:

– as part of chromosomes- an example is complete and incomplete linkage of genes;

– in a pair of homologous chromosomes- examples are complete and incomplete dominance, independent expression of allelic genes.

Non-allelic genes can also interact with each other. An example of such an interaction can be the appearance of neoplasms when crossing two, outwardly identical forms. For example, the inheritance of the ridge shape in chickens is determined by two genes - R and P: R - pink ridge, P - pea ridge.

F1 RrPp - emergence of a nut-like crest in the presence of two dominant genes;

with the genotype yrrr, a leaf-shaped crest appears.

A1. How many pairs of chromosomes are responsible for sex inheritance in dogs if they have a diploid set of 78?

3) thirty six

4) eighteen

A2. The patterns of linked inheritance refer to genes located in

1) different non-homologous chromosomes

2) homologous chromosomes

3) in one chromosome

4) non-homologous chromosomes

A3. A color blind man married a woman with normal vision, a carrier of the color blind gene. What genotype cannot they have?

1) X d X 2) XX 3) X d X d 4) XY

A4. What is the number of gene linkage groups if it is known that the diploid set of chromosomes of an organism is 36?

1) 72 2) 36 3) 18 4) 9

A5. The frequency of crossing over between genes K and C is 12%, between genes B and C - 18%, between genes K and B - 24%. What is the likely order of the genes on the chromosome if they are known to be linked?

1) К-С-В 2) К-В-С 3) С-В-К 4) В-К-С

A6. What will be the phenotypic cleavage in the offspring obtained from crossing black (A) hairy (B) guinea pigs heterozygous for two traits linked in one chromosome?

1) 1: 1 2) 2: 1 3) 3: 1 4) 9: 3: 3: 1

A7. From crossing of two gray rats heterozygous for two signs of color, 16 individuals were obtained. What will the offspring ratio be if it is known that gene C is the main color gene and in its presence gray, white and black individuals appear, and the second gene A affects the distribution of pigment. In his presence, gray individuals appear.

1) 9 gray, 4 black, 3 white

2) 7 black, 7 black, 2 white

3) 3 black, 8 white, 5 gray

4) 9 gray, 3 black, 4 white

A8. The couple had a son, hemophilic. He grew up and decided to marry a healthy woman who does not carry the hemophilia gene. What are the possible phenotypes of the future children of this married couple, if the gene is linked to the X chromosome?

1) all girls are healthy and not carriers, but boys are hemophilic

2) all boys are healthy, and girls are hemophilic

3) half of the girls are sick, the boys are healthy

4) all girls are carriers, boys are healthy

C1. Make a prediction of the appearance of a grandson - a color blind man and a healthy woman who does not carry the gene for color blindness, provided that all his sons marry healthy women who do not carry the gene for color blindness, and his daughters marry healthy men. Prove your answer by writing down the crossing scheme.

Basic terms and concepts tested in the examination paper: twin method, genealogical method, gene mutations, genomic mutations, genotypic variability, law of homologous series of hereditary variability, combinative variability, modification variability, mutations, non-hereditary variability, polyploidy, Rh factor, pedigree, Down syndrome, chromosomal mutations, cytogenetic variability.

Variability- This is a general property of living systems associated with changes in the phenotype and genotype that arise under the influence of the external environment or as a result of changes in hereditary material. Distinguish between non-hereditary and hereditary variability.

Non-hereditary variability ... Non-hereditary, or group (specific), or modification variability- these are changes in the phenotype under the influence of environmental conditions. Modification variability does not affect the genotype of individuals. The genotype, while remaining unchanged, determines the limits within which the phenotype can change. These limits, i.e. opportunities for the phenotypic manifestation of a trait are called normal reaction and inherited... The reaction rate sets the boundaries within which a specific sign can change. Different signs have different reaction rates - wide or narrow. So, for example, signs such as blood type, eye color do not change. The shape of the mammalian eye changes slightly and has a narrow reaction rate. The milk yield of cows can vary over a fairly wide range, depending on the conditions of the breed. Other quantitative traits can also have a wide reaction rate - growth, leaf size, number of kernels on the cob, etc. The wider the reaction rate, the more opportunities an individual has to adapt to environmental conditions. That is why there are more individuals with an average severity of a trait than individuals with extreme expressions. This is well illustrated by such an example as the number of dwarfs and giants in humans. There are few of them, while there are thousands of times more people with a height in the range of 160-180 cm.

The phenotypic manifestations of a trait are influenced by the cumulative interaction of genes and environmental conditions. Modification changes are not inherited, but they do not necessarily have a group character and are not always manifested in all individuals of the species under the same environmental conditions. Modifications ensure the individual is adaptable to these conditions.

Hereditary variability (combinative, mutational, indefinite).

Combinative variability arises during the sexual process as a result of new combinations of genes arising during fertilization, crossing over, conjugation, i.e. in processes accompanied by recombinations (redistribution and new combinations) of genes. As a result of combinative variability, organisms arise that differ from their parents in genotypes and phenotypes. Some combinative changes can be detrimental to an individual. For a species, however, combinative changes are generally beneficial because lead to genotypic and phenotypic diversity. This contributes to the survival of species and their evolutionary progress.

Mutational variability associated with changes in the sequence of nucleotides in DNA molecules, loss and insertion of large sections in DNA molecules, changes in the number of DNA molecules (chromosomes). Themselves such changes are called mutations... Mutations are inherited.

Among the mutations are:

– gene- causing changes in the sequence of DNA nucleotides in a particular gene, and therefore in i-RNA and the protein encoded by this gene. Gene mutations can be either dominant or recessive. They can lead to the appearance of signs that support or depress the vital functions of the body;

– generative mutations affect germ cells and are transmitted during sexual reproduction;

– somatic mutations do not affect germ cells and are not inherited in animals, but in plants they are inherited during vegetative reproduction;

– genomic mutations (polyploidy and heteroploidy) are associated with a change in the number of chromosomes in the karyotype of cells;

– chromosomal mutations are associated with rearrangements of the structure of chromosomes, a change in the position of their sections resulting from breaks, the loss of individual sections, etc.

The most common gene mutations are those that result in a change, loss, or insertion of DNA nucleotides in a gene. Mutant genes transmit other information to the site of protein synthesis, and this, in turn, leads to the synthesis of other proteins and the emergence of new traits. Mutations can occur under the influence of radiation, ultraviolet radiation, and various chemical agents. Not all mutations are effective. Some of them are corrected during DNA repair. Phenotypically, mutations appear if they did not lead to the death of the organism. Most gene mutations are recessive. Phenotypically manifested mutations, which provided individuals with either advantages in the struggle for existence, or, on the contrary, caused their death under the pressure of natural selection, are of evolutionary importance.

The mutational process increases the genetic diversity of populations, which creates the preconditions for the evolutionary process.

The frequency of mutations can be artificially increased, which is used for scientific and practical purposes.

A1. Modification variability is understood as

1) phenotypic variability

2) genotypic variability

3) reaction rate

4) any changes to the trait

A2. Indicate the trait with the widest reaction rate

1) the shape of the swallow's wings

2) eagle beak shape

3) hare molting time

4) the amount of wool in a sheep

A3. Provide correct statement

1) environmental factors do not affect the genotype of an individual

2) it is not the phenotype that is inherited, but the ability to manifest it

3) modification changes are always inherited

4) modification changes are harmful

A4. Provide an example of a genomic mutation

1) the occurrence of sickle cell anemia

2) the emergence of triploid forms of potatoes

3) creating a tailless dog breed

4) the birth of an albino tiger

A5. Changes in the DNA nucleotide sequence in the gene are associated

1) gene mutations

2) chromosomal mutations

3) genomic mutations

4) combinative rearrangements

A6. A sharp increase in the percentage of heterozygotes in the cockroach population can lead to:

1) an increase in the number of gene mutations

2) the formation of diploid gametes in a number of individuals

3) chromosomal rearrangements in some members of the population

4) change in ambient temperature

A7. Accelerated skin aging in rural versus urban areas is an example

1) mutational variability

2) combination variability

3) gene mutations caused by ultraviolet radiation

4) modification variability

A8. The main cause of chromosomal mutation can be

1) replacement of a nucleotide in a gene

2) change in ambient temperature

3) violation of meiosis processes

4) insertion of a nucleotide into a gene

IN 1. What examples illustrate modification variability

1) a person's tan

2) a birthmark on the skin

3) the density of the coat of a rabbit of the same breed

4) increase in milk yield in cows

5) six-fingered in humans

6) hemophilia

IN 2. Indicate events related to mutations

1) a multiple increase in the number of chromosomes

2) changing the undercoat of a hare in winter

3) replacement of an amino acid in a protein molecule

4) the appearance in the family of an albino

5) overgrowth of the root system of a cactus

6) the formation of cysts in protozoa

OT. Correlate the characteristic characterizing variability with its type

C1. What methods can be used to artificially increase the mutation frequency and why should this be done?

C2. Find errors in the text provided. Correct them. Indicate the numbers of sentences in which mistakes were made. Explain them.

1. Modification variability is accompanied by genotypic changes. 2. Examples of modification are hair lightening after prolonged exposure to the sun, increased milk yield of cows while improving feeding. 3. Information about modification changes is contained in genes. 4. All modification changes are inherited. 5. The manifestation of modification changes is influenced by environmental factors. 6. All signs of one organism are characterized by the same reaction rate, ie. limits of their variability.

3.7. The harmful effect of mutagens, alcohol, drugs, nicotine on the genetic apparatus of the cell. Protection of the environment from contamination by mutagens. Identification of sources of mutagens in environment(indirectly) and an assessment of the possible consequences of their influence on their own body. Hereditary human diseases, their causes, prevention

Basic terms and concepts tested in the examination paper: biochemical method, twin method, hemophilia, heteroploidy, color blindness, mutagens, mutagenesis, polyploidy.

Mutagens- these are physical or chemical factors, the influence of which on the body can lead to a change in its hereditary characteristics. These factors include X-rays and gamma rays, radionuclides, heavy metal oxides, and certain types of chemical fertilizers. Some mutations can be caused by viruses. Genetic changes in generations can also lead to such widespread in modern society agents like alcohol, nicotine, drugs. The rate and frequency of mutations depend on the intensity of the influence of these factors. An increase in the frequency of mutations leads to an increase in the number of individuals with congenital genetic abnormalities. Mutations that affect the germ cells are inherited. However, mutations in somatic cells can lead to cancer... Currently, studies are underway to identify mutagens in the environment and are being developed effective measures to neutralize them. Despite the fact that the frequency of mutations is relatively low, their accumulation in the gene pool of mankind can lead to a sharp increase in the concentration of mutant genes and their manifestation. That is why it is necessary to know about mutagenic factors and take measures at the state level to combat them.

Medical genetics - chapter anthropogenetics studying hereditary human diseases, their origin, diagnosis, treatment and prevention. The main means of collecting information about the patient is medical genetic counseling. It is carried out in relation to persons who have had hereditary diseases among their relatives. The goal is to predict the likelihood of having children with pathologies, or to exclude the occurrence of pathologies.

Consulting stages:

- identification of the carrier of the pathogenic allele;

- calculation of the probability of having sick children;

- communication of the research results to future parents, relatives.

Hereditary diseases transmitted to descendants:

- gene linked to the X chromosome - hemophilia, color blindness;

- gene linked to the Y-chromosome - hypertrichosis (hair growth of the auricle);

- gene autosomal: phenylketonuria, diabetes, polydactyly, Huntington's chorea, etc .;

- chromosomal, associated with mutations of chromosomes, for example, cat cry syndrome;

- genomic - poly- and heteroploidy - change in the number of chromosomes in the karyotype of the organism.

Polyploidy - two- and more-fold increase in the number of haploid set of chromosomes in the cell. It arises as a result of nondisjunction of chromosomes in meiosis, duplication of chromosomes without subsequent cell division, fusion of nuclei of somatic cells.

Heteroploidy (aneuploidy) - a change in the number of chromosomes characteristic of a given species as a result of their uneven divergence in meiosis. It manifests itself in the appearance of an extra chromosome ( trisomy on chromosome 21 leads to Down's disease) or the absence of a homologous chromosome in the karyotype ( monosomy). For example, the absence of the second X chromosome in women causes Turner syndrome, which manifests itself in physiological and mental disorders. Sometimes polysomy occurs - the appearance of several extra chromosomes in the chromosome set.

Methods of human genetics. Genealogical - the method of compiling genealogies from various sources - stories, photographs, paintings. The traits of ancestors are clarified and the types of inheritance of traits are established.

Inheritance types: a) autosomal dominant, b) autosomal recessive, c) sex-linked inheritance.

The person for whom the pedigree is compiled is called proband.

Twin... A method for studying genetic patterns in twins. Twins can be identical (monozygotic, identical) and heterogeneous (dizygotic, non-identical).

Cytogenetic... Method for microscopic examination of human chromosomes. Allows you to identify gene and chromosomal mutations.

Biochemical... Based on biochemical analysis, it can identify a heterozygous carrier of the disease, for example, a carrier of the phenylketonuria gene can be identified by an increased concentration phenylalanine in blood.

Population genetic... It allows you to compile the genetic characteristics of the population, to assess the degree of concentration of various alleles and the measure of their heterozygosity. For the analysis of large populations, the Hardy-Weinberg law is applied.

C1. Chorea of ​​Huntington is a severe disease of the nervous system, inherited as an autosomal trait (A).

Phenylketonuria - a disease that causes metabolic disorders, is determined by a recessive gene, is inherited in the same way. The father is heterozygous for the gene for Huntington's chorea and does not suffer from phenylketonuria. The mother does not suffer from Huntington's chorea and does not carry the genes that determine the development of phenylketonuria. What are the possible genotypes and phenotypes of children from this marriage?

C2. A woman with an absurd character married a man with a gentle character. From this marriage, two daughters and a son were born (Elena, Lyudmila, Nikolai). Elena and Nikolai turned out to be absurd in nature. Nikolay married a girl Nina with a gentle character. They had two sons, one of whom (Ivan) was a brawler, and the other a gentle man (Peter). Indicate on the pedigree of this family the genotypes of all its members.

3.8. Breeding, its tasks and practical significance. The teachings of N.I. Vavilov on the centers of diversity and origin of cultivated plants. The law of homologous series in hereditary variation. Methods for breeding new varieties of plants, animal breeds, strains of microorganisms. The value of genetics for breeding. Biological bases cultivation of cultivated plants and domestic animals

Basic terms and concepts tested in the examination paper: heterosis, hybridization, law of homologous series of hereditary variability, artificial selection, polyploidy, breed, selection, cultivar, centers of origin of cultivated plants, pure line, inbreeding.

Breeding is a science, a branch of practical activity aimed at creating new varieties of plants, animal breeds, strains of microorganisms with stable hereditary traits that are useful for humans. Theoretical basis breeding is genetics.

Breeding tasks:

- qualitative improvement of the trait;

- increasing productivity and productivity;

- increasing resistance to pests, diseases, climatic conditions.

Selection methods. Artificial selection - preservation of organisms necessary for a person and elimination, culling of others that do not meet the goals of the breeder.

The breeder sets a task, selects parental pairs, selects offspring, conducts a series of closely related and distant crosses, then conducts selection in each subsequent generation. Artificial selection happens individual and massive.

Hybridization - the process of obtaining new genetic combinations in offspring to enhance or a new combination of valuable parental traits.

Closely related hybridization (inbreeding) used to draw clean lines. The disadvantage is oppression of vitality.

Remote hybridization shifts the reaction rate towards strengthening the trait, the appearance of hybrid power (heterosis). The disadvantage is the non-breeding of the resulting hybrids.

Overcoming the sterility of interspecific hybrids. Polyploidy. G. D. Karpechenko in 1924 treated a sterile hybrid of cabbage and radish with colchicine. Colchicine caused nondisjunction of the hybrid chromosomes during gametogenesis. The fusion of diploid gametes led to the production of a polyploid hybrid of cabbage and radish (kapredki). The experiment of G. Karpechenko can be illustrated by the following scheme.

1. Before the action of colchicine

2. After the action of colchicine and artificial duplication of chromosomes:

I.V. Michurin, a domestic breeder, bred about 300 varieties fruit trees, combining the qualities of southern fruits and the unpretentiousness of northern plants.

Basic working methods:

- distant hybridization of geographically distant varieties;

- strict individual selection;

- "education" of hybrids by harsh growing conditions;

- “dominance control” with the help of the mentor method - grafting a hybrid to an adult plant that transfers its qualities to the bred variety.

Overcoming non-breeding with distant hybridization:

- method of preliminary approach - grafting of a cuttings of one species (mountain ash) was grafted onto the crown of a pear. A few years later, rowan flowers were pollinated with pear pollen. So a hybrid of rowan and pear was obtained;

- mediator method - 2 step hybridization. The almond was crossed with the semi-cultivated David peach, and then the resulting hybrid was crossed with the cultivar. Got Northern Peach;

- pollination with mixed pollen (own and foreign). An example is getting cerapadus - a hybrid of cherry and bird cherry.

The largest Russian scientist - geneticist N.I. Vavilov introduced huge contribution in plant breeding. He found that all cultivated plants grown today in different regions of the world have certain geographic

centers of origin. These centers are located in tropical and subtropical zones, that is, where cultural agriculture originated. N.I. Vavilov identified 8 such centers, i.e. 8 independent areas of introduction into cultivation of various plants.

The variety of cultivated plants in the centers of their origin, as a rule, is represented by a huge number of botanical varieties and many hereditary variants.

The law of homologous series of hereditary variation.

1. Species and genera that are genetically close are characterized by similar series of hereditary variability with such correctness that, knowing a number of forms within one species, one can foresee the finding of parallel forms in other species and genera. The closer the species and genera are genetically located in the general system, the more complete the similarity in the series of their variability.

2. Whole plant families, in general, are characterized by a certain cycle of variation, passing through all the genera and species that make up the family.

This law was derived by N.I. Vavilov based on the study of a huge number of genetically related species and genera. The closer the relationship between these taxonomic groups and within them, the more genetic similarity they have. Comparing with each other different kinds and the genera of cereals, N.I. Vavilov and his collaborators found that all cereals have similar characteristics, such as branchiness and density of the spike, pubescence of scales, etc. Knowing this, N.I. Vavilov suggested that such groups have similar hereditary variability: "if you can find an awnless form of wheat, you can find an awnless form of rye." Knowing the possible nature of changes in representatives of a certain species, genus, family, the breeder can purposefully search for, create new forms and either weed out or save individuals with the necessary genetic changes.

A1. The domestication of animals and plants is based on

1) artificial selection 3) domestication

2) natural selection 4) methodical selection

A2. In the Mediterranean center of cultivated plants,

1) rice, mulberry 3) potatoes, tomatoes

2) breadfruit, peanuts 4) cabbage, olive, rutabaga

A3. An example of genomic variation is

1) sickle cell anemia

2) polyploid form of potatoes

3) albinism

3) color blindness

A4. Roses, similar in appearance and genetically, artificially

bred by breeders form

1) breed 2) grade 3) species 4) variety

A5. The benefits of heterosis are

1) the appearance of clean lines

2) overcoming non-breeding of hybrids

3) increasing yields

4) increasing the fertility of hybrids

A6. As a result of polyploidy

1) fertility occurs in interspecific hybrids

2) fertility disappears in interspecific hybrids

3) maintains a clean line

4) the viability of hybrids is inhibited

A7. Inbreeding in breeding is used for

1) enhancing hybrid properties

2) drawing clean lines

3) increase the fertility of the offspring

4) increasing the heterozygosity of organisms

A8. The law of homologous series of hereditary variation allowed breeders with greater reliability

1) display polyploid forms

2) overcome the non-breeding of different species

3) increase the number of random mutations

4) predict the receipt of the desired traits in plants

A9. Inbreeding increases

1) heterozygosity of the population

2) frequency of dominant mutations

3) homozygosity of the population

4) the frequency of recessive mutations

IN 1. Establish a correspondence between the characteristics of the selection method and its name.

C1. Compare the results from the use of such selection methods as inbreeding, polyploidy. Explain these results.

3.9. Biotechnology, cell and genetic engineering, cloning. The role of cell theory in the formation and development of biotechnology. The importance of biotechnology for the development of breeding, agriculture, microbiological industry, preservation of the planet's gene pool. Ethical aspects of the development of some research in biotechnology (human cloning, directed changes in the genome)

Basic terms and concepts tested in the examination paper: biotechnology, genetic engineering, cell engineering.

Cellular engineering is a direction in science and breeding practice that studies methods of hybridization of somatic cells belonging to different species, the possibility of cloning tissues or whole organisms from individual cells.

One of the most widespread methods of plant breeding is the haploid method - obtaining full-fledged haploid plants from sperm or eggs.

Hybrid cells have been obtained that combine the properties of blood lymphocytes and tumor, actively multiplying cells. This allows you to quickly and in the right quantities to obtain antibodies.

Tissue culture - it is used to obtain in laboratory conditions plant or animal tissues, and sometimes whole organisms. In plant growing, it is used for the accelerated production of pure diploid lines after treatment of the initial forms with colchicine.

Genetic Engineering- artificial, purposeful change in the genotype of microorganisms in order to obtain cultures with predetermined properties.

The main method- Isolation of the necessary genes, their cloning and introduction into a new genetic environment. The method includes the following stages of work:

- isolation of a gene, its combination with a DNA molecule of a cell, which can reproduce a donor gene in another cell (inclusion in a plasmid);

- introduction of the plasmid into the genome of the recipient bacterial cell;

- selection of the necessary bacterial cells for practical use;

- research in the field of genetic engineering extends not only to microorganisms, but also to humans. They are especially relevant in the treatment of diseases associated with disorders in the immune system, in the blood coagulation system, and in oncology.

Cloning ... From a biological point of view, cloning is the vegetative propagation of plants and animals, the offspring of which carries hereditary information identical to the parent. Plants, fungi, and protozoa are cloned in nature, i.e. organisms that reproduce vegetatively. In recent decades, this term has been used when the nuclei of one organism is transplanted into the egg of another. An example of such cloning was the famous Dolly the sheep, obtained in England in 1997.

Biotechnology- the process of using living organisms and biological processes in the production of drugs, fertilizers, biological plant protection products; for biological treatment Wastewater, for the biological extraction of valuable metals from seawater, etc.

The inclusion in the genome of E. coli of the gene responsible for the formation of insulin in humans made it possible to establish the industrial production of this hormone.

In agriculture, dozens of food and forage crops have been genetically altered. In animal husbandry, the use of growth hormone obtained by biotechnology has made it possible to increase milk yield;

using a genetically modified virus to create a vaccine against herpes in pigs. With the help of newly synthesized genes introduced into bacteria, a number of the most important biologically active substances, in particular hormones and interferon, are obtained. Their production has constituted an important branch of biotechnology.

As genetic and cellular engineering advances in society, there is more and more concern about the possible manipulation of genetic material. Some fears are theoretically justified. For example, it is impossible to exclude the transplantation of genes that increase antibiotic resistance of some bacteria, the creation of new forms of food, but these works are controlled by states and society. In any case, the danger from disease, malnutrition and other shocks is much higher than from genetic research.

Prospects for genetic engineering and biotechnology:

- creation of organisms useful for humans;

- getting new drugs;

- correction and correction of genetic pathologies.

A1. The production of drugs, hormones and other biological substances is engaged in such a direction as

1) genetic engineering

2) biotechnological production

3) agricultural industry

4) agronomy

A2. When will tissue culture be most beneficial?

1) when receiving a hybrid of apple and pear

2) when breeding clean lines of smooth-seeded peas

3) if necessary, transplant skin to a person with a burn

4) when obtaining polyploid forms of cabbage and radish

A3. In order to artificially obtain human insulin by genetic engineering methods on an industrial scale, it is necessary

1) introduce the gene responsible for the synthesis of insulin in bacteria, which will begin to synthesize human insulin

2) introduce bacterial insulin into the human body

3) artificially synthesize insulin in a biochemical laboratory

4) to grow a culture of cells of the human pancreas, which is responsible for the synthesis of insulin.

C1. Why are many in society afraid of transgenic foods?

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