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

On the mother cell, a tubercle containing the nucleus is first formed. The kidney grows, reaches the size of the mother, separates

Unicellular eukaryotes, some ciliates, yeast

spore formation

Spore - a special cell, covered with a dense shell that protects from external influences

spore plants; some protozoa

vegetative reproduction:

The increase in the number of individuals of this species occurs by separating the viable parts of the vegetative body of the organism

Plants, animals

In plants

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

Lily, nightshade, gooseberry, etc.

Animals

Ordered and unordered division

Intestinal, starfish, annelids

peculiarities

prezygotic

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 grains of the yolk, mitochondria, pigments, the cytoplasm moves, pronounced bilateral symmetry (bilateral). In a number of animal species, the synthesis of protein and new RNA begins

splitting up

crushing furrows 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 divisions, a group of cells closely adjacent to each other is formed. The embryo resembles a raspberry. He got the name morula.

blastulation

the final stage of egg crushing. In the lancelet, the blastula is formed when the embryo reaches 128 cells. The blastula is shaped like a vesicle with a single layer of cells called the 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 higher on the evolutionary ladder develop three germ layers.

histogenesis and organogenesis

tissue and organs are formed

causes of manifestation

meaning

Non-hereditary (modification variability)

change in environmental conditions, as a result of which the organism changes within the limits of the reaction rate specified by the genotype

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

white cabbage in a hot climate does not form a head; 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 beneficial, harmful and indifferent, dominant and recessive

reproductive isolation > new species, genera > microevolution.

combinative

arises spontaneously within a population when crossing, when new combinations of genes appear in the offspring.

distribution of new hereditary changes that serve as material for selection.

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

Correlative (correlative)

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

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

leggy animals have a long neck.

aromorphosis

idioadaptation

general degeneration

hypergenesis

Emergence of electron transport chains (which enabled photosynthesis and aerobic respiration)

Galapagos finches (different types of beaks)

In bivalve mollusks, 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 carnassials, a decrease in body temperature through increased oral breathing (sweat glands are absent)

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

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

In ladybugs, salamanders - warning coloration

Loss of vision in moles, proteas, deep-sea

The appearance of the axial skeleton - chords

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

Think!

“We live in a world where people know much more about the internals of a car or how a laptop or touchscreen works than they do about their own bodies. But for each of us it is vital 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 communicating 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 the 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, there are coordinated processes 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 offspring.

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 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. Of the more than 100 known chemical elements about 90 are found in the human body. They are divided into groups: organogens (oxygen, hydrogen, carbon, nitrogen), macroelements (for example, calcium, potassium, sodium, iron, phosphorus, chlorine) and microelements (for example, cobalt, copper, zinc, iodine, fluorine, etc.) . Most content among inorganic compounds, water (about 60%) and mineral salts are accounted for. Organic substances in the body contain carbohydrates, lipids, proteins, fats, nucleic acids, etc.

Cellular level of organization. The main parts of human cells, as well as plants, animals and fungi, are the surface apparatus, the cytoplasm and the nucleus. It is at this level that all the properties of life are manifested 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 that unite into groups to perform certain vital functions. Tissue - a collection of cells and intercellular substance, similar in origin, structural features and functions. In the human body, as well as 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 usually participate in the formation of an organ, but one of them is decisive for its activity. For example, in the bones such tissue is connective bone, in the heart - muscle. An organ is a part of an organism

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, digestive, 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, and sensory systems are distinguished. 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 system levels of organization are distinguished.

How is the integrity of the human body achieved?

The processes occurring at all levels of human organization are always coordinated with each other. Such consistency and coordination occur due to the processes of regulation of the functions of the human body.

Regulation of human functions is a set of processes that provide a coordinated and coordinated response of the body to changes in environmental conditions. These processes occur at the level of cells that generate signals. So 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 the 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 internal fluids to ensure a long-term and general effect on cells, tissues and organs.

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

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

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

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

ACTIVITY

Learning to know

Task 1. Consider illustration 2 and name the components and organelles of the cell. Remember what functions the designated organelles of the cell perform.

Task 2. Consider illustration 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 the relationship of a person with the outside world.

One of the functions of philosophy is to help a person in cognitive activity. The famous German philosopher G. W. F. 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 textbook material.

The organism as a biological system

Reproduction of organisms, its significance. Methods of reproduction, 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. Application of artificial insemination in plants and animals

Terms and concepts tested in examination work: asexual reproduction, vegetative reproduction, hermaphroditism, zygote, ontogenesis, fertilization, parthenogenesis, sexual reproduction, budding, spores.

reproduction in the organic world. The ability to reproduce is one of the most important signs of life. This ability is manifested already at the molecular level of life. Viruses, penetrating into 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.

There are the following forms of reproduction:

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

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 reproduce.

- Vegetative reproduction by parts of the body is characteristic of multicellular organisms - plants, sponges, coelenterates, some worms. Plants can propagate vegetatively by cuttings, layering, root offspring and other parts of the body.

- Budding - one of the options for vegetative reproduction is characteristic of yeast and intestinal 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, so it is often used by plant breeders to preserve useful properties varieties.

sexual reproduction A process in which genetic information from two individuals is combined. Combining genetic information can occur when conjugation (temporary connection of individuals for the exchange of information, as occurs in 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, drone bees). In this case, a new organism develops from an unfertilized egg, but before that, the formation of gametes always occurs.

Sexual reproduction in angiosperms occurs by double fertilization. The fact is that haploid pollen grains are formed in the anther of the flower. The nuclei 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 again, forming two sperm. One of them, penetrating into the ovary, fertilizes the egg, and the other merges 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 bisexual individuals (hermaphrodites) produce both eggs and sperm. In most algae, two identical germ cells merge. Fusion of haploid gametes results in fertilization and the formation of a diploid zygote. 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. Offspring carry new genetic combinations that distinguish them from their parents and from each other. Various combinations of genes that appear in the offspring in the form of new traits of interest to humans are selected by breeders to develop new breeds of animals or plant varieties. In some cases, apply artificial insemination. This is done both in order to obtain 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) this adaptation to adverse environmental conditions

3) provides combinative variability of organisms

4) ensures the genetic constancy 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 oogenesis and spermatogenesis is that:

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

2) eggs contain more chromosomes than sperm

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

4) oogenesis takes place with one division of the primary germ 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 probability of meeting gametes with each other

A6. Asexual reproduction dominates the life cycle

1) hydras 3) sharks

A7. Gametes in ferns are formed

1) in sporangia 3) on leaves

2) on the growth 4) in disputes

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

1) queen bee

2) worker 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) cuckoo flax moss 3) medicinal chamomile

2) bracken fern 4) common pine

Part B

IN 1. Choose the right statements

1) The formation of gametes in plants and animals occurs according to one 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 of an angiosperm is fertilized by two sperm

6) The endosperm of angiosperms is triploid.

IN 2. Establish a correspondence between the forms of reproduction and their characteristics

VZ. Set the correct sequence of events that occur during double fertilization of flowering plants.

A) fertilization of the egg and the central cell

B) the formation of a pollen tube

B) pollination

D) the formation of two sperm

D) 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 the errors in the given text, indicate the numbers of the sentences in which they are made, and correct them. 1) Diploid pollen grains are formed in the anthers of angiosperms. 2) The nucleus of the pollen grain is divided into two nuclei: vegetative and generative. 3) The pollen grain falls on the stigma of the pistil and germinates 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) Another sperm fuses with the nuclei of the central cells, forming the endosperm.

Ontogeny and its inherent regularities. Specialization of cells, formation of tissues, organs. Embryonic and postembryonic development of organisms. Life cycles and alternation of generations. Causes of impaired development of organisms

Ontogenesis. Ontogenesis - this is the individual development of the organism from the moment of 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 ontogenesis. 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 takes place in a non-larval or intrauterine form. It includes all forms of ovoviviparity, the development of the 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. AT ontogeny distinguish two periods embryonic - from the formation of a zygote to release from the egg membranes and postembryonic from the moment of birth to death. Embryonic period a multicellular organism consists of the following stages: zygotes; blastula- stages of development of a multicellular embryo after crushing 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-layered embryo, covered blastoderm, and the formation of the primary body cavity - blastoceles ; gastrulae- stages of formation of germ layers - ectoderm, endoderm (in two-layer coelenterates and sponges) and mesoderm (in three-layer in other multicellular animals). In intestinal animals, specialized cells are formed at this stage, such as stinging, genital, skin-muscular, etc. The process of gastrula formation is called gastrulation .

Neirula- Stages of laying individual organs.

Histo- and organogenesis- the stage of appearance of specific functional, morphological and biochemical differences between individual cells and parts of the developing embryo. In Vertebrate animals in organogenesis it is possible to distinguish:

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 vision and hearing;

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

c) the process of formation from endoderm intestines and related organs - liver, pancreas, lungs. The successive 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 are never put to work together. At a particular time, only a part of the genes work.

Postembryonic period is divided into the following steps:

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

- infants (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 and senile - after 75 years).

EXAMPLES OF TASKS

Part A

A1. The two-layer structure of the flow is characteristic of

1) annelids 3) coelenterates

2) insects 4) protozoa

A2. 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 cleavage of the zygote, a

1) gastrula 3) neurula

2) blastula 4) mesoderm

A5. Develops from the endoderm

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

A6. Separate organs of a multicellular organism are laid down 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 the dog 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 of

1) the actions of certain genes at a certain time

2) 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 unspecialized cells?

1) blastula 3) early neurula

2) gastrula 4) late neurula

Part B

IN 1. Which of the following refers to embryogenesis?

1) fertilization 4) spermatogenesis

2) gastrulation 5) crushing

3) neurogenesis 6) oogenesis

IN 2. Select the features characteristic of blastula

1) an embryo in which a chord 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 a single layer of cells

VZ. Match the organs of a multicellular embryo with the germ layers from which these organs are formed.

Part C

C1. Give examples of direct and indirect postembryonic development on the example of insects.

The organism as a biological system

3.2. Reproduction of organisms, its significance. Methods of reproduction, 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. Application of artificial insemination in plants and animals

asexual reproduction, vegetative reproduction, hermaphroditism, zygote, ontogenesis, fertilization, parthenogenesis, sexual reproduction, budding, spores.

reproduction in the organic world. The ability to reproduce is one of the most important signs of life. This ability is manifested already at the molecular level of life. Viruses, penetrating into 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.

There are the following forms of reproduction:

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

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 reproduce.

- Vegetative reproduction by parts of the body is characteristic of multicellular organisms - plants, sponges, coelenterates, some worms. Plants can propagate vegetatively by cuttings, layering, root offspring and other parts of the body.

- Budding - one of the options for vegetative reproduction is characteristic of yeast and intestinal 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, so it is often used by plant breeders to preserve the useful properties of the variety.

sexual reproduction A process in which genetic information from two individuals is combined. Combining genetic information can occur when conjugation (temporary connection of individuals for the exchange of information, as occurs in 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, drone bees). In this case, a new organism develops from an unfertilized egg, but before that, the formation of gametes always occurs.

Sexual reproduction in angiosperms occurs by double fertilization. The fact is that haploid pollen grains are formed in the anther of the flower. The nuclei 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 again, forming two sperm. One of them, penetrating into the ovary, fertilizes the egg, and the other merges 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 bisexual individuals (hermaphrodites) produce both eggs and sperm. In most algae, two identical germ cells merge. Fusion of haploid gametes results in fertilization and the formation of a diploid zygote. 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. Offspring carry new genetic combinations that distinguish them from their parents and from each other. Various combinations of genes that appear in the offspring in the form of new traits of interest to humans are selected by breeders to develop new breeds of animals or plant varieties. In some cases, artificial insemination is used. This is done both in order to obtain 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) this adaptation to adverse environmental conditions

3) provides combinative variability of organisms

4) ensures the genetic constancy 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 oogenesis and spermatogenesis is that:

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

2) eggs contain more chromosomes than sperm

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

4) oogenesis takes place with one division of the primary germ 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 probability of meeting gametes with each other

A6. Asexual reproduction dominates the life cycle

1) hydras 3) sharks

A7. Gametes in ferns are formed

1) in sporangia 3) on leaves

2) on the growth 4) in disputes

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

1) queen bee

2) worker 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) cuckoo flax moss 3) medicinal chamomile

2) bracken fern 4) common pine

IN 1. Choose the right statements

1) The formation of gametes in plants and animals occurs according to one 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 of an angiosperm is fertilized by two sperm

6) The endosperm of angiosperms is triploid.

IN 2. Establish a correspondence between the forms of reproduction and their characteristics

VZ. Set the correct sequence of events that occur during double fertilization of flowering plants.

A) fertilization of the egg and the central cell

B) the formation of a pollen tube

B) pollination

D) the formation of two sperm

D) development of the embryo and endosperm

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

C2. Find the errors in the given text, indicate the numbers of the sentences in which they are made, and correct them. 1) Diploid pollen grains are formed in the anthers of angiosperms. 2) The nucleus of the pollen grain is divided into two nuclei: vegetative and generative. 3) The pollen grain falls on the stigma of the pistil and germinates 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) Another 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 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 ontogenesis. 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 takes place in a non-larval or intrauterine form. It includes all forms of ovoviviparity, the development of the 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. AT ontogeny distinguish two periods embryonic - from the formation of a zygote to release from the egg membranes and postembryonic from the moment of birth to death. Embryonic period a multicellular organism consists of the following stages: zygotes; blastula- stages of development of a multicellular embryo after crushing 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-layered embryo, covered blastoderm, and the formation of the primary body cavity - blastoceles; gastrulae- stages of formation of germ layers - ectoderm, endoderm (in two-layer coelenterates and sponges) and mesoderm (in three-layer in other multicellular animals). In intestinal animals, specialized cells are formed at this stage, such as stinging, genital, skin-muscular, etc. The process of gastrula formation is called gastrulation.

Neirula- Stages of laying individual organs.

Histo- and organogenesis- the stage of appearance of specific functional, morphological and biochemical differences between individual cells and parts of the developing embryo. In Vertebrate animals in organogenesis it is possible to distinguish:

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 chords, muscles, kidneys, skeleton, blood vessels;

c) the process of formation from endoderm intestines and related organs - liver, pancreas, lungs. The successive 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 are never put to work together. At a particular time, only a part of the genes work.

Postembryonic period is divided into the following steps:

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

- infants (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 and senile - after 75 years).

A1. The two-layer structure of the flow is characteristic of

1) annelids 3) coelenterates

2) insects 4) protozoa

A2. 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 cleavage of the zygote, a

1) gastrula 3) neurula

2) blastula 4) mesoderm

A5. Develops from the endoderm

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

A6. Separate organs of a multicellular organism are laid down 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 the dog 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 of

1) the actions of certain genes at a certain time

2) 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 unspecialized cells?

1) blastula 3) early neurula

2) gastrula 4) late neurula

IN 1. Which of the following refers to embryogenesis?

1) fertilization 4) spermatogenesis

2) gastrulation 5) crushing

3) neurogenesis 6) oogenesis

IN 2. Select the features characteristic of blastula

1) an embryo in which a chord 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 a single layer of cells

VZ. Match the organs of a multicellular embryo with the germ layers from which these organs are formed.

C1. Give examples of direct and indirect postembryonic development on the example of insects.

allelic genes, analyzing crossing, gene interaction, gene, genotype, heterozygosity, gamete purity hypothesis, homozygosity, dihybrid crossing, G. Mendel's laws, quantitative traits, crossing over, flying, multiple alleles, monohybrid cross, independent inheritance, incomplete dominance, uniformity rule, splitting, phenotype, cytological foundations 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 involves 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 occur during sexual reproduction. The role of variability lies in the fact that it "supplies" new genetic combinations that are subject to the action of natural selection, and heredity preserves these combinations.

The main genetic concepts include the following:

Gene- a section of a DNA molecule that encodes information about the sequence of amino acids in one protein molecule.

allele- a pair of genes responsible for an alternative (different) manifestation of the same trait. For example, two allelic genes located in the same loci (places) of homologous chromosomes are responsible for eye color. Only one of them can be responsible for the development of brown eyes, 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 organism on this basis. If allelic genes determine the different development of a trait, they talk about heterozygous body.

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

The totality of an organism's genes is called genotype of this organism. The genotype of an organism is described by the words - "homozygous" or "heterozygous". However, not all genes are expressed. 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 talk about a dominant or recessive phenotype.

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

The development of genetics led to the development of many scientific areas and, above 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. A roundworm has 19,000 genes, while mustard has 25,000. The differences between humans and chimpanzees are 1% of the genes, and with the mouse, 10%. Man also inherited genes that are 3 billion years old and relatively young genes.

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

3.5. Patterns of heredity, their cytological basis. Mono- and dihybrid crossing. Patterns of inheritance established by G. Mendel. Linked inheritance of traits, violation of the linkage of genes. Laws of T. Morgan. Chromosomal theory of heredity. Sex genetics. Inheritance of sex-linked traits. Genotype as complete system. Development of knowledge about the genotype. The human genome. Interaction of genes. Solution of genetic problems. Drawing up cross-breeding 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, morganide, heredity, independent inheritance, incomplete dominance, uniformity rule, splitting, phenotype, chromosome theory of heredity, cytological bases Mendel's laws.

The success of Gregor Mendel's work was due to the fact that he correctly chose the object of study 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 - high - low, with yellow and green seeds, with smooth and wrinkled seeds.

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

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

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

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

– seed shape (round / non-round);

- seed color (yellow / green);

– seed coat (smooth / wrinkled), etc.

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

Since the examination work requires students to be able 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 phenotype recessive parent. The remaining 50% of heterozygotes will be phenotypically different from them. For example, from red-flowered and white-flowered snapdragons 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 certain 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

ah? aa > 50% Aa and 50% aa

Mendel's second law or splitting law. When crossing heterozygous hybrids of the first generation with each other, in the second generation, splitting according to this trait is detected. This splitting is of a natural statistical nature: 3: 1 in terms of phenotype and 1: 2: 1 in terms of 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 was derived on the basis of an analysis of the results obtained by crossing individuals that differ in two pairs of alternative traits. For example: a plant that gives yellow, smooth seeds are crossed with a plant that produces green, wrinkled seeds.

For further notation, the Punnett lattice is used:

In the second generation, 4 phenotypes may appear in 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 their corresponding traits are transmitted independently of each other. This law is correct:

– for diploid organisms;

– for genes located on different homologous chromosomes;

- with 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 the purity of gametes, only one of the homologous chromosomes of a given pair is always in the norm in a sperm or egg. That is why, during fertilization, the diploid set of chromosomes of the 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 - meetings of gametes carrying different (or identical) alternative genes.

A1. The dominant allele is

1) a pair of identical genes

2) one of two allelic genes

3) a gene that suppresses the action of another gene

4) repressed gene

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

1) several signs of the body

2) one sign of the organism

3) several proteins

4) tRNA molecule

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

1) alternative

2) dominant

3) not completely dominant

4) recessive

A4. Allelic genes are located in

1) identical sections of homologous chromosomes

2) different parts of homologous chromosomes

3) identical regions of non-homologous chromosomes

4) different parts of non-homologous chromosomes

A5. Which entry reflects a diheterozygous organism:

1) AABB 2) AaBv 3) AaBvSs 4) aaBBss

A6. Determine the phenotype of a pumpkin with the CC BB genotype, knowing that white color dominates over yellow, and disc-shaped fruits dominate over spherical

1) white, spherical 3) yellow discoid

2) yellow, spherical 4) white, discoid

A7. What offspring will result from crossing a polled (hornless) homozygous cow (horned bull 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 protruding ears (A) dominates the gene for normally flattened ears, and the gene for non-red (B) hair dominates the gene for red hair. What is the genotype of a lop-eared, red-haired father, if, in a marriage with a non-red woman with normally flattened ears, he had only lop-eared, non-red children?

1) AABB 2) AaBB 3) AABB 4) AABB

A9. What is the probability of having 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 traits?

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

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

1) linkage of genes

2) mutual influence of genes

3) feature splitting

4) independent distribution of gametes

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

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

C1. Determine the possible genotypes of 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 of the problem in the form of two crossover schemes. How many crossover schemes can be analyzed in solving 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 locus(place);

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

- between homologous chromosomes, there can be an exchange of regions ( crossing over); as a result of crossing over, gametes arise, 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;

is the set of chromosomes in cells of this type ( karyotype) is characteristic feature type;

- 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. One unit of distance between genes is taken as 1 morganid (1% of crossing over) or the percentage of occurrence of crossover individuals. With a value of this value of 10 morganids, it can be argued that the frequency of chromosome crossing at the points of location of these genes is 10% and that new genetic combinations will be revealed in 10% of the offspring.

To determine 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 on the chromosome and the distance between the genes on the same chromosome. These conclusions of Morgan and his collaborators are called the chromosome 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.

The tasks illustrating the chromosome theory are quite complex and cumbersome to write down, therefore, in the examination USE papers assignments for sex-linked inheritance are given.

Sex genetics. Sex-linked inheritance. The chromosome sets of different sexes differ in the structure of the sex chromosomes. The male Y chromosome does not contain many of the alleles found on the X chromosome. The 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 not having an allele on 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, the gene for color blindness or hemophilia), but she herself is not sick, then she is a carrier. If this gene is passed on to sons, they may be sick with this disease, because there is no allele on 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 resulting zygote. In birds, females are heterogametic and males are homogametic.

An example of sex-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, which carries the gene that determines it, gets to the boy, then this trait will definitely appear in him. If you have read famous novel Patrick Suskind's "Perfume", then you remember that it was about a baby who did not have a smell.

Consider an example of sex-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, Y.

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

Genotype as an integral, historically established 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 the totality of the genes of an organism. According to the latest data, a person has about 35 thousand genes.

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

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

– within the chromosomes– an example is complete and incomplete linkage of genes;

– on 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 two outwardly identical forms are crossed. For example, the inheritance of the shape of the comb in chickens is determined by two genes - R and P: R - rose-shaped comb, P - pea-shaped comb.

F1 RrPp - the appearance of a walnut ridge in the presence of two dominant genes;

with the genotype ggrr, a leaf-shaped ridge appears.

A1. How many pairs of chromosomes are responsible for the inheritance of sex in dogs if their diploid set is 78?

3) thirty six

4) eighteen

A2. Linked inheritance patterns refer to genes located in

1) different non-homologous chromosomes

2) homologous chromosomes

3) in one chromosome

4) non-homologous chromosomes

A3. A colorblind man married a woman with normal vision, a carrier of the gene for colorblindness. A child with what genotype they can not 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 the K and C genes is 12%, between the B and C genes, 18%, and between the K and B genes, 24%. What is the likely order of genes on a chromosome if they are known to be linked.

1) K-S-B 2) K-B-S 3) S-B-K 4) B-K-S

A6. What will be the splitting by phenotype in the offspring obtained from crossing black (A) hairy (B) guinea pigs heterozygous for two traits linked on the same chromosome?

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

A7. From the crossing of two gray rats heterozygous for two color traits, 16 individuals were obtained. What will be the ratio of offspring 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 the 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 with hemophilia. He grew up and decided to marry a healthy woman who did not carry the hemophilia gene. What are the possible phenotypes of 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 with hemophilia

2) all the boys are healthy, and the 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 forecast for the appearance of a color-blind grandson of a color-blind man and a healthy woman who does not carry the color blind gene, provided that all his sons marry healthy women who do not carry the color blind gene, and his daughters marry healthy men. Prove your answer by writing the crossover scheme.

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

Variability- this is a general property of living systems associated with changes in the phenotype and genotype that occur 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 (defined), 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 reaction rate and inherited. The reaction norm sets the boundaries within which a particular feature can change. Different signs have a different reaction rate - wide or narrow. So, for example, such signs as blood type, eye color do not change. The shape of the mammalian eye changes insignificantly 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 characteristics may also have a wide reaction rate - growth, leaf size, number of grains per 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 expression of a trait than individuals with its 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 do not always appear in all individuals of a species under the same environmental conditions. Modifications ensure that the individual is adapted to these conditions.

hereditary variability (combinative, mutational, indeterminate).

Combination variability occurs during the sexual process as a result of new combinations of genes that occur 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 the species, combinative changes are, in general, useful, 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, deletions and insertions of large sections in DNA molecules, changes in the number of DNA molecules (chromosomes). Such changes are called mutations. Mutations are inherited.

Mutations include:

– genetic- causing changes in the sequence of DNA nucleotides in a particular gene, and therefore in the mRNA and protein encoded by this gene. Gene mutations are both dominant and recessive. They can lead to the appearance of signs that support or depress the vital activity of the organism;

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

– somatic mutations do not affect germ cells and are not inherited in animals, while 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 cell karyotype;

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

The most common gene mutations, as a result of which there is a change, loss or insertion of DNA nucleotides in the gene. Mutant genes transmit different 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, various chemical agents. Not all mutations are effective. Some of them are corrected during DNA repair. Phenotypically, mutations are manifested if they did not lead to the death of the organism. Most gene mutations are recessive. Of evolutionary importance are phenotypically manifested mutations that provided individuals with either advantages in the struggle for existence, or vice versa, which caused their death under the pressure of natural selection.

The mutation process increases the genetic diversity of populations, which creates the prerequisites for the evolutionary process.

The frequency of mutations can be increased artificially, 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 in the feature

A2. Indicate the trait with the widest reaction rate

1) the shape of the wings of a swallow

2) the shape of an eagle's beak

3) hare molting time

4) the amount of wool in a sheep

A3. Specify the 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. Give an example of a genomic mutation

1) the occurrence of sickle cell anemia

2) the appearance of triploid potato forms

3) the creation of a tailless dog breed

4) the birth of an albino tiger

A5. With a change in the sequence of DNA nucleotides in a gene,

1) gene mutations

2) chromosomal mutations

3) genomic mutations

4) combinative rearrangements

A6. A sharp increase in the percentage of heterozygotes in a population of cockroaches 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. The accelerated skin aging of rural residents compared to urban ones is an example

1) mutational variability

2) combination variability

3) gene mutations under the influence of 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 meiotic processes

4) insertion of a nucleotide into a gene

IN 1. What examples illustrate modification variability

1) human tan

2) 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. Specify events related to mutations

1) a multiple increase in the number of chromosomes

2) changing the undercoat of a hare in winter

3) amino acid replacement in a protein molecule

4) the appearance of an albino in the family

5) growth of the root system of a cactus

6) the formation of cysts in protozoa

VZ. Match the feature that characterizes variability with its type

C1. What are the ways to achieve an artificial increase in the frequency of mutations and why should this be done?

C2. Find errors in the given text. Fix them. Indicate the numbers of sentences in which errors were made. Explain them.

1. Modification variability is accompanied by genotypic changes. 2. Examples of modification are hair lightening after long exposure to the sun, increasing the 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, i.e. the limits of their variability.

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

The main 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, certain types of chemical fertilizers. Some mutations can be caused by viruses. Genetic changes in generations can also be caused by such common 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 anomalies. Mutations that affect germ cells are inherited. However, mutations that occur in somatic cells can lead to cancer. Research is currently underway to identify mutagens in the environment and effective measures for their disposal. Despite the fact that the frequency of mutations is relatively low, their accumulation in the human gene pool 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 human hereditary 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 in whom hereditary diseases were observed among relatives. The goal is to predict the probability of having children with pathologies, or to exclude the occurrence of pathologies.

Stages of counseling:

- identification of the carrier of the pathogenic allele;

- calculation of the probability of the birth of sick children;

– communication of the results of the study to future parents, relatives.

Hereditary diseases transmitted to offspring:

- 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 chromosome mutations, for example, cat's cry syndrome;

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

polyploidy - two or more fold increase in the number of haploid set of chromosomes in the cell. Occurs as a result of nondisjunction of chromosomes in meiosis, doubling 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. Manifested 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 a second X chromosome in women causes Turner syndrome, which manifests itself in physiological and mental disorders. Sometimes there is polysomy - the appearance of several extra chromosomes in the chromosome set.

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

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

The person for whom a pedigree is drawn up is called proband.

Gemini. A method for studying genetic patterns on twins. Twins are identical (monozygous, identical) and fraternal (dizygotic, non-identical).

cytogenetic. Microscopic study of human chromosomes. Allows you to identify gene and chromosomal mutations.

Biochemical. Based on biochemical analysis, it allows to 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. Allows you to make a genetic characteristic 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. Huntington's chorea 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 according to the same type. The father is heterozygous for the gene of 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 a quarrelsome 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 an absurd character. Nikolai 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 the genotypes of all its members on the pedigree of this family.

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

The main terms and concepts tested in the examination paper: heterosis, hybridization, law of homological series of hereditary variability, artificial selection, polyploidy, breed, selection, variety, 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 beneficial to humans. Theoretical basis breeding is genetics.

Selection tasks:

– qualitative improvement of the trait;

– increase in yield 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 parent pairs, selects offspring, conducts a series of closely related and distant crosses, then selects 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 the oppression of viability.

distant hybridization shifts the reaction rate in the direction of strengthening the trait, the appearance of hybrid power (heterosis). The disadvantage is the non-crossability 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 chromosomes of the hybrid during gametogenesis. The fusion of diploid gametes led to the production of a polyploid hybrid of cabbage and radish (kapredki). G. Karpechenko's experiment 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 management" using the mentor method - grafting a hybrid to an adult plant that transfers its qualities to the bred variety.

Overcoming non-crossing in distant hybridization:

- the method of preliminary approach - grafting a cutting of one species (mountain ash) was grafted onto the crown of a pear. A few years later, rowan flowers were pollinated by pear pollen. So a hybrid of mountain ash 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 a cultivar. Got "Northern Peach";

- Pollination by mixed pollen (own and someone else's). An example is the production of 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 geographical

centers of origin. These centers are located in tropical and subtropical zones, i.e., where cultivated agriculture originated. N.I. Vavilov singled out 8 such centers, i.e. 8 independent areas of introduction to the culture 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 variability.

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

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

This law was introduced 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 greater the genetic similarity they have. Comparing with each other different kinds and genera of cereals, N.I. Vavilov and his collaborators found that all cereals have similar characteristics, such as branching and density of the ear, pubescence of scales, etc. Knowing this, N.I. Vavilov suggested that such groups have similar hereditary variability: "if you can find a awnless form of wheat, you can also find a awnless form of rye." Knowing the possible nature of changes in representatives of a certain species, genus, family, a breeder can purposefully search, 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, swede

A3. An example of genomic variation is

1) sickle cell anemia

2) polyploid form of potato

3) albinism

3) color blindness

A4. Roses that are similar in appearance and genetically, artificially

bred by breeders form

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

A5. The benefits of heterosis are

1) the appearance of clean lines

2) overcoming the non-crossing of hybrids

3) increase in productivity

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) a clean line is maintained

4) the viability of hybrids is inhibited

A7. Inbreeding in breeding is used for

1) strengthening hybrid properties

2) drawing clean lines

3) increase the fertility of offspring

4) increasing the heterozygosity of organisms

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

1) display polyploid forms

2) overcome the non-crossing of different species

3) increase the number of random mutations

4) predict the acquisition of the desired traits in plants

A9. Inbreeding increases

1) population heterozygosity

2) frequency of dominant mutations

3) homozygosity of the population

4) frequency of recessive mutations

IN 1. Establish a correspondence between the features 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, the microbiological industry, and the preservation of the planet's gene pool. Ethical aspects of the development of some research in biotechnology (human cloning, directed changes in the genome)

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

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

One of the common 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 proliferating cells. This allows you to quickly and in the right quantities to obtain antibodies.

tissue culture - used to obtain in the laboratory plant or animal tissues, and sometimes whole organisms. In crop production, it is used to accelerate the production of pure diploid lines after treatment of the original forms with colchicine.

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

Main method- isolation of the necessary genes, their cloning and introduction into a new genetic environment. The method includes the following work steps:

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

– introduction of a plasmid into the genome of a bacterial cell – a recipient;

– selection of 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, in oncology.

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

Biotechnology– the process of using living organisms and biological processes in the production of medicines, fertilizers, biological plant protection products; for biological treatment Wastewater, for the biological extraction of valuable metals from sea water, 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.

AT agriculture managed to genetically change dozens of food and fodder crops. In animal husbandry, the use of biotechnologically produced growth hormone has increased milk yields;

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 are obtained, in particular hormones and interferon. Their production constituted an important branch of biotechnology.

With the development of genetic and cell engineering, there is more and more concern in society about the possible manipulation of genetic material. Some concerns are theoretically justified. For example, it is impossible to exclude the transplantation of genes that increase resistance to antibiotics of some bacteria, the creation of new forms of food products, 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:

- the creation of organisms useful to humans;

- getting new medicines;

– correction and correction of genetic pathologies.

A1. Production of drugs, hormones and other biological substances deals with such a direction as

1) genetic engineering

2) biotech production

3) agricultural industry

4) agronomy

A2. When would tissue culture be the most useful method?

1) upon receipt of a hybrid of apple and pear

2) when breeding pure lines of smooth-seed peas

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

4) upon receipt of 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 a gene responsible for the synthesis of insulin into bacteria that will begin to synthesize human insulin

2) inject bacterial insulin into the human body

3) artificially synthesize insulin in a biochemical laboratory

4) grow a cell culture of the human pancreas responsible for the synthesis of insulin.

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

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