The chromosome set of potato somatic cells is 48. Cell life cycle

General lesson: “Mitosis. Meiosis"

Target: summarize knowledge on the topic “Mitosis. Meiosis"

Objectives: 1. educational:

a) generalization of knowledge on the topic

b) solving USE tasks

c) the formation of ideas about the main similarities and differences between the processes of mitosis and meiosis, their biological essence;

d) developing the skills to consistently organize the processes of mitosis and meiosis;

2. developing:

a) developing skills in working with different types of information and ways of presenting it;

b) development of skills to analyze and compare cell division processes;

3. educational:

a) Development of cognitive interest in information from different fields of science;

b) increasing the intellectual level of students through the introduction of computer technologies and gaming activities.

Educational equipment: computer with multimedia projector.

Lesson structure:

1. Organizational moment (2 min);

2. Updating of knowledge, basic terms and concepts related to the processes of cell division;

3. Generalization of knowledge about the processes of mitosis and meiosis (game);

4. Testing;

5. Conclusions;

6. Homework.

Lesson plan.

1. Organizational moment

2. Updating knowledge, basic terms and concepts related to cell division processes: conjugation, crossing over, bivalents, chromosome, chromatid, cell cycle.

3. Game. On the slide is a table in which the questions are encrypted. Green squares are simple questions (1 point), yellow squares are questions of medium difficulty (2 points), red squares are difficult questions (3 points). The class is divided into 2 teams (before the lesson starts). Each person takes turns choosing questions and scoring points. The team with the most points wins.

Simple questions (1 point)

1. What is the phase of mitosis, which is characterized by the separation of sister chromatids to different poles of the cell?

2. Name the phase of meiosis in which DNA replication occurs?

3. Name the phase of meiosis in which the divergence of homologous chromosomes to different poles of the cell occurs?

4. Establish the correct sequence of mitosis phases?

5. In what phase of meiosis does conjugation and crossing over occur?

6. Name the cell organelle involved in the formation of the division spindle.

7. Despiralization of chromosomes occurs in...

8. What process is shown in the diagram? What do the letters mean?

9. Meiosis is...

10. Which division of meiosis is similar to mitosis? What is the difference?

11. Name the process by which genetic material is successfully distributed between daughter cells?

12.Find the error in the text: During prophase of mitosis, chromosomes actively spiral. In metaphase, the spiralization of chromosomes becomes maximum and the chromatids diverge to different poles of the cell. Anaphase occurs very quickly.

Medium difficulty questions (2 points)

1) Establish the sequence of mitotic processes:

A) despiralization of chromosomes

B) formation of a fission spindle

B) divergence of daughter chromatids to opposite poles of the cell

D) chromosome spiralization

D) ordered arrangement of chromosomes, consisting of 2 chromatids, at the equator of the cell

E) formation of 2 daughter cells

Answer: GBDVAE

2) What processes occur during meiosis?

3) denaturation

4) crossing over

5) conjugation

6) broadcast

Answer: 245

3) Establish a correspondence between the features and processes of cell division.

FEATURES PROCESSES

A) daughter cells contain 1) meiosis

haploid set of chromosomes 2) mitosis

B) includes 2 divisions going

one after another

C) as a result, two are formed

daughter cells

D) the number of chromosomes in daughters

cells – 2p

D) is one of the phases of gametogenesis

E) characteristic of somatic cells

Answer: 112212

4) Establish the sequence of processes of the first meiotic division:

A) chromosome conjugation

B) crossing over

B) arrangement of pairs (bivalents) of homologous chromosomes at the equator of the cell

D) the location of homologous chromosomes, consisting of 2 chromatids, to opposite poles of the cell

D) spiralization of chromosomes with the formation of bivalents

E) formation of nuclei, division of the cytoplasm - formation of 2 daughter cells

— Answer: DABVGE

5) What processes are shown in the figure? When do these processes occur? What is their biological significance?

6) Determine the type and phase of division of the cell shown in the figure. What processes occur in this phase?

DIV_ADBLOCK321">

3) 3× 10-9 mg

3) The total mass of DNA molecules in the 46 chromosomes of the nucleus of a human somatic cell is

6×10-9 mg. Determine the mass of all DNA molecules in interphase, the end of meiosis telophase 1 and meiosis telophase 2. Explain your answer.

Answer: 1) 2×6×10-9 = 12×10-9 mg

3) 3× 10-9 mg

4) The total mass of all DNA molecules in one human egg is about 3 × 10 -9 mg. Determine the mass of all DNA molecules in sperm, in a somatic cell before the start of division and after its completion. Explain your answer.

— Answer: 1) 3×10 -9 mg 2) 12×10 -9 mg 3) 6×10 -9 mg

5) What is the biological significance of meiosis? Give at least 3 signs.

Answer: 1) Maintains the constancy of the number of chromosomes over generations

2) creates new gene combinations, providing combinative variability

3) provides genetic heterogeneity in populations

4) is one of the stages of the formation of gametes, spores in plants.

6) What is the biological significance of mitosis?

Answer:

1) maintains the genetic stability of cells

2) the basis for growth and development

3) the basis of embryonic development

4) underlies regeneration

5) the basis of asexual reproduction

6) maintains the correct functioning of the body’s organs and tissues.

Let's summarize the game.

Consolidation (testing)

Option 1.

1. The disappearance of the nuclear membrane and nucleoli occurs

1) interphase 2) prophase 3) metaphase 4) anaphase

2. Chromosome conjugation is characteristic of

1) prophase of mitosis 2) prophase of the first division of meiosis

3) prophase of the second division of meiosis 4) metaphase of mitosis

3. As a result of the first meiotic division, one mother cell produces

1) four daughter cells with the number of chromosomes equal to the mother cell

2) four daughter cells with the number of chromosomes halved

3) two daughter cells with twice the number of chromosomes

4) two daughter cells with a halved set of chromosomes

4. The cell center in the process of mitosis is responsible for

1) protein biosynthesis 2) chromosome spiralization

3) movement of cytoplasm 4) formation of a spindle

5.Indicate the name of the last phase of mitosis

1) telophase 2) metaphase 3) anaphase 4) prophase

6. Establish the sequence in which these processes occur in mitosis.

A) chromosomes are located along the equator

B) chromatids move towards the poles of the cell

B) two daughter cells are formed

D) chromosomes spiral, each consisting of two chromatids

C5. The chromosome set of a dog's somatic cell is 78. Determine the chromosome set and the number of DNA molecules in one of the cells in prophase of mitosis, in anaphase of mitosis, in telophase of mitosis. Explain what processes occur during these periods and how they affect the change in the number of chromosomes.

Option 2.

1. Due to conjugation and crossing over, during the formation of gametes,

1) halving the number of chromosomes 2) doubling the number of chromosomes

3) exchange of genetic information between homologous chromosomes

4) increase in the number of female and male reproductive cells

2. In metaphase of mitosis occurs

1) divergence of chromatids 2) doubling of chromosomes 3) placement of chromosomes in the equatorial plane of the cell 4) formation of the nuclear membrane and nucleoli

3. The essence of meiosis is

1) the formation of cells with a diploid set of chromosomes

2) doubling the amount of DNA in body cells

3) divergence of chromatids to the cell poles

4) the formation of gametes with a haploid set of chromosomes

4. The divergence of chromatids to the cell poles occurs in

1) anaphase 2) telophase 3) prophase 4) metaphase

5. Meiosis differs from mitosis 1) by the presence of interphase

2) the number of daughter cells and the set of chromosomes in them
3) the presence of prophase, metaphase, anaphase and telophase

4) processes of spiralization and despiralization of chromosomes

6.Choose 3 correct answers:

The similarity between prophase of mitosis and prophase of 1meiosis lies in what happens

1) disappearance of the nuclear membrane

2) conjugation

3) crossing over

4) formation of a fission spindle

5) chromosome spiralization

6) chromosome doubling

C5. The chromosome set of somatic potato cells is 48. Determine the chromosome set and the number of DNA molecules in one of the ovule cells before the onset of meiosis, in anaphase of meiosis 1, in telophase of meiosis 2. Explain what processes occur during these periods and how they affect the change in the number of chromosomes and DNA.

Answers.

— Option 1 Option 2

— 6) GABV

— C5 C5

1) 78xr. 156DNA 1) 48chr. 96 DNA

2) 156 xr 156DNA 2) 48 xr. 96 DNA

3) 78xr 78DNAxr. 24 DNA

Conclusions from the lesson.

Homework.

No. 1. The chromosome set of somatic cells of spinach is 12. Determine the chromosome set and the number of DNA molecules in one of the ovule cells before the onset of meiosis, in metaphase of meiosis1 and telophase of meiosis. Explain what processes occur during these periods and how they affect changes in the number of DNA and chromosomes.

No. 2. The potato karyotype contains 48 chromosomes (2p). Determine the number of chromosomes in anaphase of mitosis in endosperm cells if it has a triploid set of chromosomes (3n). Explain your answer.

Task No. 1.

Consider the proposed scheme. Write down the missing term in your answer, indicated by a question mark in the diagram.

Explanation: in plants, the root system is taprooted (typical of Dicotyledons) or fibrous (typical of Monocots). The correct answer is fibrous.

Task No. 2.

Below is a list of theories, laws, patterns. All of them, except two, relate to theories, laws, patterns, and rules of biology. Find two concepts that “fall out” from the general series and write down the numbers under which they are indicated in the table.

1. Law of splitting

2. Ecological pyramid rule

3. Law of conservation of energy

4. Law of Uniformity

5. The law of universal gravitation

Explanation: Biological laws (laws or rules) include the law of splitting, the rule of the ecological pyramid and the law of uniformity (the remaining laws are taken from physics). The correct answer is 3.5.

Task No. 3.

The set of chromosomes of potato germ cells is 24. What set of chromosomes do the somatic cells of this organism have? Write down only the number of chromosomes in your answer.

Explanation: germ cells contain a haploid (single) set of chromosomes, and somatic cells (all other cells) contain a diploid (double) set. The correct answer is 48.

Task No. 4.

All but two of the following features can be used to describe the functions of nucleic acids in a cell. Identify two characteristics that “drop out” from the general list and write down the numbers under which they are indicated in the table.

1. Maintain homeostasis

2. Transfer hereditary information from the nucleus to ribosomes

3. Participate in protein biosynthesis

4. Part of the cell membrane

5. Transport amino acids

Explanation: Nucleic acids are DNA and RNA. DNA- deoxyribonucleic acid, located in the nucleus (or nucleoid) of each cell and is responsible for storing genetic information. RNA- ribonucleic acid, there are three types: ribosomal, transport, information. All types of RNA are synthesized on DNA. Ribosomal RNA (rRNA) forms ribosomes, mRNA carries out transcription - copies a certain section of DNA and leaves the nucleus into the cytoplasm. tRNA brings the amino acids necessary for the synthesis of a specific protein to the ribosome. The correct answer is 1, 4.

Task No. 5.

Establish a correspondence between the characteristic and the process: for each position given in the first column, select the corresponding position from the second column.

Characteristic

A. Occurs in chloroplasts

B. Glucose is synthesized

B. Is a stage of energy metabolism

D. Occurs in the cytoplasm

D. Photolysis of water occurs

Process

1. Photosynthesis

2. Glycolysis

Explanation: Photosynthesis is the process of converting solar energy into the energy of chemical bonds, carried out by phototrophs. It occurs in chloroplasts, during which photolysis of water occurs, glucose is synthesized, and other processes. Glycolysis is one of the stages of energy metabolism that occurs in the cytoplasm. The correct answer is 11221.

Task No. 6.

What ratio of phenotypes will be obtained by crossing two heterozygotes with complete dominance of genes? Write the answer as a sequence of numbers in descending order.

Explanation: When crossing two heterozygotes: Aa x Aa, we obtain the following gametes: A, a x A, a.

Segregation by genotype - 1AA: 2Aa: 1aa.

Phenotype split: 3:1.

The correct answer is 31.

Task No. 7.

Below is a list of characteristics of variability. All but two of them are used to describe the characteristics of chromosomal variation. Find two characteristics that “fall out” from the general series and write down the numbers under which they are indicated in the table.

1. Loss of a chromosome section

2. Rotate a section of a chromosome by 180 degrees

3. Decrease in the number of chromosomes in the karyotype

4. Appearance of an additional X chromosome

5. Transfer of a chromosome section to a non-homologous one

Explanation: chromosomal variability - such variability, which is associated with a violation of the structure of chromosomes, leads to serious changes that can be detected using a microscope. Such mutations include losses of chromosome sections (deletions), addition of sections, rotation of a chromosome section by 180°, and the appearance of repeats. The correct answer is 34.

Task No. 8.

Establish a correspondence between the method of reproduction and the example: for each position given in the first column, select the corresponding position from the second column.

Example

A. Sporulation in sphagnum

B. Seed propagation of spruce

B. Parthenogenesis in bees

D. Reproduction by bulbs in tulips

D. Laying eggs by birds

E. Egg spawning in fish

Reproduction method

1. Sexual

2. Asexual

Explanation: Examples of asexual reproduction among the listed answer options are sporulation in sphagnum (spores are not germ cells) and reproduction by bulbs in tulips (since the bulb is a modified shoot). Everything else is an example of sexual reproduction, since germ cells take part in it (even from at least one individual, as in parthenogenesis). The correct answer is 211211.

Task No. 9.

The similarity between animal cells and bacteria is that they have

1. Ribosomes

2. Cytoplasm

3. Glycocalyx

4. Mitochondria

5. Formed core

6. Cytoplasmic membrane

Explanation: all cells (both eukaryotic and prokaryotic) have cytoplasm, ribosomes and a cytoplasmic membrane. You can see more about different types of cells. The correct answer is 126.

Task No. 10.

Establish a correspondence between the insect and its type of development: for each position given in the first column, select the corresponding position from the second column.

Insect

A. Honey bee

B. May beetle

B. Asian locust

G. Cabbage white

D. Green grasshopper

Type of development

1. With incomplete transformation

2. With complete transformation

Explanation: development with incomplete transformation is characteristic of grasshoppers and locusts. For all the others listed - with a complete transformation. The correct answer is 22121.

Task No. 11.

Arrange the systematic categories of plants in the correct order, starting with the smallest. Write down the corresponding sequence of numbers in the table.

1. Ranunculaceae
2. Angiosperms
3. Acrid buttercup
4. Dicotyledons
5. Buttercup
Explanation: Let us give the systematic position of the buttercup.
Species: Buttercup
Genus: Buttercup
Family: Ranunculaceae
Class: Dicotyledons
Division: Angiosperms (Flowers)
Correct answer: 35142.

Task No. 12.
Choose three correct answers out of six and write down the numbers under which they are indicated in the table
Receptors are nerve endings in the human body that
1. Perceive information from the external environment
2. Receive impulses from the internal environment
3. They perceive excitation transmitted to them via motor neurons
4. Located in the executive body
5. Convert perceived stimuli into nerve impulses
6. Implement the body’s response to irritation from the external and internal environment
Explanation: A receptor is the ending of a sensitive neuron that perceives irritation from the external and internal environments and converts the irritation into a nerve impulse.
Therefore, the correct answer is 125.

Task No. 13.
Establish a correspondence between the function of the human gland and its type: for each position given in the first column, select the corresponding position from the second column.
Gland function
A. Form fat
B. Participate in thermoregulation
B. Produce nutritious food for the child
D. Remove minerals from the body
D. Increase skin elasticity
Gland type
1. Sweat
2. Greasy
3. Milky
Explanation: Sweat glands produce sweat and are part of the body's thermoregulation system, and they also remove minerals.
With the help of the mammary glands, women feed their children in the first year of life. And the sebaceous glands produce fat (fat), which increases the elasticity of the skin. The correct answer is 21312.

Task No. 14.
Establish the sequence of parts of the reflex arc as a nerve impulse passes through it. Write down the corresponding sequence of numbers in the table.
1. Sensory neuron
2. Working body
3. Interneuron
4. Section of the cerebral cortex
5. Receptor
6. Motor neuron
Explanation: Let's look at the reflex arc diagram.

The picture shows that the reflex arc begins with the receptor (the end of the sensitive neuron), then the signal travels along the sensitive neuron
to the interneuron in the brain (division of the cerebral cortex), then the processed signal from the brain goes along the process of the motor neuron to the working organ. The correct answer is 513462.

Task No. 15.
Choose three correct answers out of six and write down the numbers under which they are indicated in the table.
What examples illustrate the achievement of biological progress in plants through aromorphoses?
1. The presence of double fertilization
2. Root formation in ferns
3. Reducing evaporation by forming a waxy coating on the leaves
4. Increased pubescence of leaves in angiosperms
5. Formation of fruits with seeds in angiosperms
6. Reducing the growing season for plants growing in harsh climates
Explanation: aromorphosis is a change in the body that leads to an increase in its level of organization. That is, examples of aromorphoses are:
the presence of double fertilization, the formation of roots in ferns and the formation of fruits with seeds in angiosperms. The remaining changes are private and do not lead to an increase in the level of the organization. The correct answer is 125.

Task No. 16.
Establish a correspondence between the selection criterion and its type: for each position given in the first column, select the corresponding position from the second column.
Sign
A. Leads to the creation of new animal breeds and plant varieties
B. Promotes the creation of organisms with hereditary changes necessary for humans
B. Acts in nature for millions of years
D. Leads to the emergence of new species and the formation of adaptation to the environment
D. Conducted by a person
Type of selection
1. Natural
2. Artificial
Explanation: natural selection occurs in living nature over millions of years, leading to the emergence of new species and the formation of adaptation to the environment,
and artificial selection - carried out by humans, leads to the creation of new breeds of animals and plant varieties with hereditary characteristics needed by humans. The correct answer is 22112.

Task No. 17.
Choose three correct answers out of six and write down the numbers under which they are indicated in the table.
The biogeocenosis of the river's fresh water body is characterized by
1. The presence of producers of organic matter - autotrophs
2. The absence of organic destroyers - decomposers
3. The presence of flowering plants in shallow waters
4. Absence of predatory fish
5. The constant number of animal populations inhabiting it
6. Closed cycle of substances
Explanation: in a natural biogeocenosis all components of the food chain (producers, consumers, decomposers) are present, which means
autotrophs are present (for example, flowering plants in shallow water), consumers can be represented by predatory fish, natural biogeocenoses are not characterized by constancy in numbers, since population waves constantly occur in populations due to various factors,
But natural biogeocenosis is characterized by a closed circulation of substances. The correct answer is 136.

Task No. 18.
Establish a correspondence between the cause of speciation and its method: for each position given in the first column, select the corresponding position from the second column.
Causes
A. Expansion of the range of the original species
B. Stability of the range of the original species
B. Division of the species’ range by various barriers
D. Diversity of variability of individuals within the range
D. Diversity of habitats within a stable range
Methods of speciation
1. Geographical
2. Ecological
Explanation: reasons associated with changes in habitats (stability of the range of the original species, division of the range of the species by various barriers) we will attribute to geographical speciation, and
all other reasons are environmental (what happens inside the original area). The correct answer is 12122.

Task No. 19.
Establish the sequence of processes occurring during the change of biogeocenoses (succession).
1. Colonization by shrubs
2. Colonization of bare rocks by lichens
3. Building a sustainable community
4. Germination of herbaceous plant seeds
5. Population of the territory with mosses
Explanation: succession - change of biogeocenoses. Let’s imagine that the area has burned out and not a single herbaceous plant remains, which means we need to develop anew, starting with the colonization of bare rocks by lichens, then
mosses, then the seeds of herbaceous plants brought by the wind germinate, then shrubs appear and a stable community is formed (we can compare the change of biogeocenoses with the evolution of plants). The correct answer is 25413.

Task No. 20.
Analyze the table. Fill in the empty cells of the table using the concepts and terms, examples given in the list. For each lettered cell, select the appropriate term from the list provided.

List of terms and concepts
1. Hereditary
2. Birth of a white-eyed individual from red-eyed Drosophila parents
3. Change in fur color in the white hare depending on temperature
4. Combinative
5. Non-hereditary
Explanation: mutational variability is hereditary (this is the basis of evolution), A is hereditary. Combinative variability leads to the formation of a new phenotype in the offspring using a combination of parental gametes, B - combinative. Modification variability - variability depending on environmental conditions (for example, temperature) within the normal range of the reaction. B - 3. The correct answer is 143.

Task No. 21.
Study the graph showing the distribution of pumpkin seeds by size. Select statements that can be formulated based on the analysis of the proposed schedule. Write down the numbers of the selected statements in your answer.

1. The greater the deviation from the average value of a trait, the lower the frequency of occurrence of this trait

2. The variation curve of a graph is a graphic expression of the nature of the variability of a characteristic

3. The average value of the trait is not found in natural populations

4. The average value of a characteristic is a deviation from the norm

Explanation: as we see in the population there are a large number of individuals with an average trait, and fewer with deviations, therefore, the first statement is suitable. This graph also represents a graphic expression of the nature of the variability of the trait. The correct answer is 12.

Task No. 22.

The biosphere is a global ecosystem consisting of a large number of smaller systems. Each of them has a specific composition and structure. What is the structure of an ecosystem? Justify your answer.

Explanation: An ecosystem is a system of living organisms that live in a certain territory and have trophic connections with each other (and in natural ecosystems the cycle of substances is closed). The structure of an ecosystem is characterized by two indicators: species (number of species and their abundance) and spatial (distribution of organisms in the space of a given territory). The spatial indicator, in turn, includes two characteristics - horizontal (the distribution of organisms in the horizontal direction - for example, mosaic) and vertical (the arrangement of organisms in the vertical direction - for example, layering).

Task No. 23.

Determine the type and class of the animal depicted in the picture. By what signs can this be done? What are the digestive features of this animal? Explain your answer.

Explanation: The figure shows an organism of the Arachnida class of the Arthropod type. We determined this because this organism has four pairs of walking legs, a cephalothorax and an abdomen. Digestion of spiders is extraorganismal, that is, the spider catches its victims in the web (they stick to the web), then injects a mixture of gastric enzymes into the victim and leaves it for a while. The spider then sucks up the semi-digested internal contents of the victim.

Task No. 24.

Find errors in the given text. Indicate the numbers of the sentences in which errors were made and correct them.

1. The educational tissue of angiosperms ensures plant growth. 2. When cambium cells divide, the plant stem grows in length. 3. Sieve tubes carry water and minerals. 4. The integumentary tissue is formed by cells tightly adjacent to each other. 5. Stomata are located between the cells of the conducting tissue.

Explanation: sentence 2 - when cambium cells divide, the plant stem grows not in length, but in thickness. 3 - sieve tubes carry organic substances from the leaves to all plant organs, and water and minerals are carried through the xylem. 5 - stomata are located between the cells of the integumentary tissue rather than the conductive tissue.

Task No. 25.

Why is the bud of an angiosperm plant considered an embryonic shoot? Provide at least three pieces of evidence.

Explanation: Let's consider the structure of the vegetative bud of an angiosperm plant

A bud is considered a rudimentary shoot, since it has all the shoot organs (but in an embryonic state) - leaves, stem, buds. And from such a vegetative bud a real shoot grows.

Task No. 26.

Give at least three examples of changes in a mixed forest ecosystem that could result from a decline in the number of insectivorous birds.

Explanation: Insectivorous birds eat insects. If the number of insectivorous birds decreases, then the number of insects increases (since few people eat them) and they begin to destroy plants, that is, the number of plants decreases. On the other hand, insectivorous birds are eaten by predators, particularly birds of prey. As the number of insectivorous birds decreases, the number of birds of prey also decreases.

Task No. 27.

The chromosome set of a somatic plant cell is 20. Determine the chromosome set and the number of DNA molecules in the ovule cells before the start of meiosis prophase 1 and at the end of meiosis 1 telophase. Explain the results obtained.

Explanation: somatic cells have a diploid set of chromosomes (that is, double), and sex cells have a haploid set. In interphase (before division), DNA doubling occurs, which means that in prophase of meiosis 1 set remains diploid - 2n (20 chromosomes), and the number of DNA molecules is double, that is, 40. In telophase of meiosis 1, division has already occurred (it happened back in anaphase) and the number of both chromosomes and DNA was divided in half, that is, the chromosome set is n (1 chromosomes), and the number of DNA molecules is 2c (20 DNA molecules).

Rear No. 28.

A blue-eyed, fair-haired man and a diheterozygous brown-eyed, dark-haired woman entered into marriage. Determine the genotypes of the married couple, as well as the possible genotypes and phenotypes of the children. Establish the probability of having a child with a dihomozygous genotype.

Explanation: A - brown eyes

a - blue eyes

B - dark hair

c - blond hair

R: aavv x AaVv

G: av x AB, av, Av, aV

F1: AaBv - brown eyes, dark hair

aavv - blue eyes, blond hair

Aaav - brown eyes, blond hair

aaVv - blue eyes, dark hair

The probability of having a child with each genotype is 25%. (and the probability of having a child with a dihomozygous genotype (aabb) is 25%)

Signs are not gender-linked. This is where the law of independent inheritance comes into play.

G.S. Kalinova, T. V. Mazyarkina Biology Typical test tasks. Unified State Exam 2017. 10 options.

A selection of materials for task No. 27 on the topic: “Task in cytology” is presented. To perform successfully, you need to know the theory. Having familiarized themselves with the plan for completing assignments, graduates will accurately understand the technology for completing such assignments. The topic of the assignment covers the school subject of biology. Here are tasks to find errors in the text from part 2

task 27.doc

subject Text

image With pictures

Task 27 “Cytology problem” “Protein biosynthesis” 1. The tRNA anticodons arrive at the ribosomes in the following nucleotide sequence UCG, CGA, AAU, CCC. Determine the sequence of nucleotides on mRNA, the sequence of nucleotides on DNA encoding a specific protein and the sequence of amino acids in a fragment of a synthesized protein molecule, using the genetic code table: Genetic code (mRNA) First base Second base Third base U Ph e n P H E N L E Y L E Y L E Y L E Y L E Y L E Y I L E I L E I L E M E T W A L C S E R S E R S E R S E R P about P about P about P about T t e T t t t t t e t t re A la AT T ir T t ir - - G s G s Gln Gln A s n A s n L i z L i z A s p G C i s C i s - T r i A r g A r g A r g A r g S e r S e r A r g A r g G l and U C A G U C A G U C A G U C A U C A G

V a l V a l V a l A l a A l a A la A s p G l u G l u G l and G l and G l and G 2. The sequence of amino acids in a fragment of a protein molecule is as follows: FENGLUMET. Using the genetic code table, determine the possible DNA triplets that encode this protein fragment. 3. It is known that all types of RNA are synthesized on a DNA matrix. The fragment of the DNA molecule on which the tRNA section is synthesized has the following nucleotide sequence TTGGAA AAACGGATCT. Establish the nucleotide sequence of the tRNA region that is synthesized on this fragment. Which mRNA codon will correspond to the central anticodon of this tRNA? Which amino acid will be transported by this tRNA? Explain your answer. To solve the task, use the genetic code table. 4. 30 tRNA molecules were involved in the translation process. Determine the number of amino acids that make up the synthesized protein, as well as the number of triplets and nucleotides in the gene that encodes this protein. 5. Determine the nucleotide sequence of the mRNA, tRNA anticodons and the amino acid sequence of the corresponding fragment of the protein molecule (using the genetic code table), if the fragment of the DNA chain has the following nucleotide sequence: GT GCTGTCAAAA. 6. One of the DNA chains has the nucleotide sequence: TsATGGCTGT–TCC–GTC. Explain how the structure of a protein molecule will change if the fourth triplet of nucleotides in the DNA chain is doubled? 7.TRNA molecules with anticodons UGA, AUG, AGU, GGC, AAU participate in the biosynthesis of the polypeptide. Determine the nucleotide sequence of the section of each chain of the DNA molecule that carries information about the polypeptide being synthesized, and the number of nucleotides containing adenine (A), guanine (G), thymine (T), cytosine (C) in a double-stranded DNA molecule. Explain your answer. 8.TRNAs with anticodons participated in protein biosynthesis: UUA, GGC, CGC, AUU, CGU. Determine the nucleotide sequence of the section of each chain of the DNA molecule that carries information about the polypeptide being synthesized, and the number of nucleotides containing adenine, guanine, thymine, cytosine in a double-stranded DNA molecule. 9. Ribosomes from different cells, the entire set of amino acids and identical mRNA and tRNA molecules were placed in a test tube, and all conditions for protein synthesis were created. Why will one type of protein be synthesized in a test tube on different ribosomes? 10. Determine: the nucleotide sequence of the mRNA, the anticodons of the corresponding tRNAs and the amino acid sequence of the corresponding fragment of the protein molecule (using the genetic code table), if the fragment of the DNA chain has the following nucleotide sequence: GTGTATGGAAGT. 11. A fragment of a DNA chain has the following nucleotide sequence: TACCCTCTCTTG. Determine the nucleotide sequence of mRNA, anticodons of the corresponding tRNAs and ami

the acid sequence of the corresponding fragment of a protein molecule using a genetic code table. 12. A fragment of a DNA chain has the following nucleotide sequence: TTACAGGTTTTAT. Determine the nucleotide sequence of the mRNA, the anticodons of the corresponding tRNAs, and the amino acid sequence of the corresponding fragment of the protein molecule using the genetic code table. 13. Protein consists of 100 amino acids. Determine how many times the molecular weight of the gene region encoding a given protein exceeds the molecular weight of the protein if the average molecular weight of an amino acid is 110, and of a nucleotide is 300. Explain your answer. 14. 30 tRNA molecules were involved in the translation process. Determine the number of amino acids that make up the synthesized protein, as well as the number of triplets and nucleotides in the gene that encodes this protein. 15. It is known that all types of RNA are synthesized on a DNA matrix. The fragment of the DNA molecule on which the region of the central loop of tRNA is synthesized has the following nucleotide sequence ATAGCTGAACGGATCT. Establish the nucleotide sequence of the tRNA region that is synthesized on this fragment and the amino acid that this tRNA will carry during protein biosynthesis if the third triplet corresponds to the tRNA anticodon. Explain your answer. To solve the problem, use the genetic code table. 16. A section of a DNA molecule has the following composition: - GATGAATAGTGCTTC. List at least 3 consequences that can result from an accidental replacement of the seventh nucleotide of thymine with cytosine (C). 17. A fragment of a DNA chain has the nucleotide sequence GTGTATGGAAGT. Determine the sequence of nucleotides in the mRNA, the anticodons of the corresponding tRNAs, and the sequence of amino acids in a fragment of the protein molecule using the genetic code table. 18. The ribosomal gene fragment has the sequence ATTGCCGATTACCAAAGTACCAAAT. What will be the RNA sequence encoded by this region? What class of RNA will it belong to? What will be its function? 19. The ribosomal gene fragment has the sequence CCCTATTGTATTACGGGAAGAGGGCATT. What will be the RNA sequence encoded by this region? What class of RNA will it belong to? What will be its function? 20. A section of a DNA molecule has the following composition: GATGAATAGTGCTTC. List at least 3 consequences that can result from an accidental replacement of the seventh nucleotide of thymine with cytosine (C). 21.TRNA anticodons are given. Using the genetic code table, determine the amino acid sequence in a fragment of a protein molecule, mRNA codons and triplets in a fragment of the gene encoding this protein. tRNA anticodons: GAA, GCA, AAA, ACC. 22. It is known that all types of RNA are synthesized on a DNA matrix. The fragment of the DNA chain on which the region of the central loop of tRNA is synthesized has the following nucleotide sequence: TCCGCATACGATAGG. Determine the nucleotide sequence of the tRNA region that is synthesized on this fragment and the amino acid that this tRNA will carry during protein biosynthesis if the third triplet is a tRNA anticodon. Explain your answer. To solve the task, use the genetic code table. 23.IRNA consists of 156 nucleotides. Determine the number of amino acids included in the protein it encodes, the number of tRNA molecules involved in the biosynthesis of this protein, and the number of triplets in the gene encoding the primary structure of the protein. Explain your results.

24. As a result of a mutation in a fragment of a protein molecule, the amino acid threonine (tre) was replaced by glutamine (gln). Determine the amino acid composition of a fragment of a normal and mutated protein molecule and a fragment of a mutated mRNA, if normally the mRNA has the sequence: GUCAGCAGUCCA-AU. Explain your answer. To solve the task, use the genetic code table. 25. It is known that all types of RNA are synthesized on a DNA matrix. The fragment of the DNA chain on which the central loop region of tRNA is synthesized has the following nucleotide sequence: ACGGTAATTGCTATC. Determine the nucleotide sequence of the tRNA region that is synthesized on this fragment and the amino acid that this tRNA will carry during protein biosynthesis if the third triplet corresponds to the tRNA anticodon. Explain your answer. To solve the task, use the genetic code table. 26. As a result of a mutation in a fragment of a protein molecule, the amino acid phenylalanine (phen) was replaced by lysine (lys). Determine the amino acid composition of a fragment of a normal and mutated protein molecule and a fragment of a mutated mRNA, if normally the mRNA has the sequence: CCTGCAACGUUCCAAU. Explain your answer. To solve the task, use the genetic code table. 27.TRNA molecules with the anticodons UAC, UUU, GCC, CAA in this sequence participate in the biosynthesis of the polypeptide. Determine the corresponding nucleotide sequence in mRNA, DNA, and amino acid sequence in a fragment of a protein molecule using the genetic code table. 28. The biosynthesis of a fragment of a protein molecule involved sequential tRNA molecules with anticodons ACC, GUC, UGA, CCA, AAA. Determine the amino acid sequence of the synthesized fragment of the protein molecule and the nucleotide sequence of the section of the double-stranded DNA molecule in which information about the primary structure of the protein fragment is encoded. Explain the sequence of your actions. To solve the problem, use the genetic code table. 29. The biosynthesis of a fragment of a protein molecule involved sequential tRNA molecules with anticodons AAG, AAU, GGA, UAA, CAA. Determine the amino acid sequence of the synthesized fragment of the protein molecule and the nucleotide sequence of the section of the double-stranded DNA molecule in which information about the primary structure of the protein fragment is encoded. Explain the sequence of your actions. To solve the problem, use the genetic code table. 30. The biosynthesis of a fragment of a protein molecule involved sequential tRNA molecules with anticodons AGC, ACC, GUA, CUA, CGA. Determine the amino acid sequence of the synthesized fragment of the protein molecule and the nucleotide sequence of the section of the double-stranded DNA molecule in which information about the primary structure of the protein fragment is encoded. Explain the sequence of your actions. To solve the problem, use the genetic code table. 31. A fragment of a double-stranded DNA molecule is given. Using the genetic code table, determine which fragments of protein molecules can be encoded by the DNA encoded by this region. List at least three steps in this process. Prove your answer. DNA AAA – TTT – YYY – CCC 32. It is known that all types of RNA are synthesized on a DNA matrix. The fragment of the DNA chain on which the region of the central loop of tRNA is synthesized has the following nucleotide sequence: TGCCATTCGTTACG. Establish the nucleotide sequence of the tRNA region that is synthesized on this fragment and the amino acid that this tRNA will transfer into TTT - AAA - CCC - YGG

in the process of protein biosynthesis, if the third triplet corresponds to the tRNA anticodon. Explain your answer. To solve the task, use the genetic code table. 33. A fragment of an mRNA chain has the nucleotide sequence: TsGAGUAUGTSUGG. Determine the sequence of nucleotides on one chain of a DNA molecule, tRNA anticodons and the sequence of amino acids that corresponds to a given gene fragment using the genetic code table. 34. A fragment of a DNA chain has the following sequence of nucleotides: TTA GAA TAT TsAG GAC Determine the sequence of nucleotides on mRNA, the anticodons of the corresponding tRNAs and the sequence of amino acids in a fragment of a protein molecule encoded by the specified DNA fragment, using the genetic code table 35. A fragment of a DNA chain has the following nucleotide sequence: TTA GAA TAT CAG GAC Determine the nucleotide sequence on the mRNA, the anticodons of the corresponding tRNA and the amino acid sequence in the fragment of the protein molecule encoded by the indicated DNA fragment, using the genetic code table. 36. It is known that all types of RNA are synthesized on a DNA matrix. The fragment of the DNA molecule on which the region of the central loop of tRNA is synthesized has the following nucleotide sequence: CGTGGGGGCTAGG CTG. What amino acid will be carried by tRNA synthesized on this DNA fragment if its third triplet corresponds to an anticodon? Explain your answer. Use the genetic code table to solve. 37. A fragment of a DNA chain has the nucleotide sequence TTTAGCTGTCGGAAG. As a result of the mutation that occurred in the third triplet, the third nucleotide was replaced by nucleotide A. Determine the sequence of nucleotides in the mRNA from the original fragment of the DNA chain and the changed one. Explain what happens to a fragment of a protein molecule and its properties after a DNA mutation occurs. Use the genetic code table to solve. 38. The genetic apparatus of the virus is represented by an RNA molecule, a fragment of which has the following nucleotide sequence: GUGAAAAGAUCAUGCGUGG. Determine the nucleotide sequence of a double-stranded DNA molecule, which is synthesized as a result of reverse transcription on the RNA of the virus. Establish the sequence of nucleotides in mRNA and amino acids in the protein fragment of the virus, which is encoded in the found fragment of the DNA molecule. The matrix for the synthesis of mRNA, on which the synthesis of the viral protein occurs, is the second strand of double-stranded DNA. To solve the problem, use the genetic code table. 39. A fragment of a DNA chain has the nucleotide sequence TTTAGCTGTCGGTGTAG. As a result of the mutation that occurred in the fifth triplet, the first nucleotide T was replaced by nucleotide A. Determine the sequence of nucleotides in the mRNA from the original fragment of the DNA chain and from the changed one. Using the genetic code table, identify the amino acid resulting from the mutation and explain what can happen to the protein molecule and its properties after the DNA mutation occurs. “Cell division” 1. The total mass of all DNA molecules in the 46 somatic chromosomes of one human somatic cell is 6x10-9 mg. Determine the mass of all DNA molecules in the sperm and in the somatic cell before the start of division and after its completion. Explain your answer.

2.What division of meiosis is similar to mitosis? Explain how it is expressed and what set of chromosomes in the cell it leads to. 3. Explain the similarities and differences between mutational and combinational variability. 4.What chromosome set is characteristic of the cells of the embryo and endosperm of the seed and leaves of a flowering plant. Explain the result in each case. 5. The chromosome set of somatic wheat cells is 28. Determine the chromosome set and the number of DNA molecules in one of the ovule cells before the onset of meiosis, in anaphase of meiosis 1 and in anaphase of meiosis 2. Explain what processes occur during these periods and how they affect change decrease in the number of DNA and chromosomes. 6.What chromosome set is characteristic of the cell nuclei of the epidermis of the leaf and the eight-nucleated birth sac of the ovule of a flowering plant? Explain from what initial cells and as a result of what division these cells are formed. 7.Down syndrome in humans occurs with trisomy 21 pairs of chromosomes. Explain the reasons for the appearance of such a chromosome set in humans. 8.Indicate the number of chromosomes and the number of DNA molecules in the prophase of the first and second meiotic cell division. What event happens to chromosomes during prophase of the first division? 9.A somatic cell of an animal is characterized by a diploid set of chromosomes. Determine the chromosome set (n) and the number of DNA molecules (c) in the cell in prophase of meiosis I and metaphase of meiosis II. Explain the results in each case. 10.What chromosome set is characteristic of gametes and spores of the cuckoo flax moss plant? Explain from which cells and as a result of what division they are formed. 11. Drosophila somatic cells contain 8 chromosomes. How will the number of chromosomes and DNA molecules in the nucleus change during gametogenesis before the start of division and at the end of the telophase of meiosis I? Explain the results in each case. 12.A somatic cell of an animal is characterized by a diploid set of chromosomes. Determine the chromosome set (n) and the number of DNA molecules (c) in the cell at the end of telophase of meiosis I and anaphase of meiosis II. Explain the results in each case. 13What are the features of meiosis that provide gamete diversity? Please indicate at least three features. 14.A somatic cell of an animal is characterized by a diploid set of chromosomes. Determine the chromosome set (n) and the number of DNA molecules (c) in the cell before meiosis I and prophase of meiosis II. Explain the results in each case. 15.What chromosome set is characteristic of the gametophyte and gametes of sphagnum moss? Explain from what initial cells and as a result of what division these cells are formed? 16.What chromosome set is characteristic of the gametophyte and gametes of sphagnum moss? Explain from what initial cells and as a result of what division these cells are formed? 17.Indicate the number of chromosomes and the number of DNA molecules in the prophase of the first and second meiotic cell division. What event happens to chromosomes during prophase of the first division?

18. In cattle there are 60 chromosomes in somatic cells. Determine the number of chromosomes and DNA molecules in ovarian cells during oogenesis in interphase before the start of division and after division of meiosis I. Explain the results obtained at each stage. 19. Drosophila somatic cells contain 8 chromosomes. What number of chromosomes and DNA molecules are contained in the nucleus during gametogenesis before the onset of meiosis I and meiosis II? Explain how such a number of chromosomes and DNA molecules are formed. 20. Consider the human karyotype and answer the questions. 1. What gender is this person? 2. What abnormalities does this person’s karyotype have? 3. What events can cause such deviations? 21. Consider the human karyotype and answer the questions. 1. What gender is this person? 2. What abnormalities does this person’s karyotype have? 3. What events can cause such deviations? 22.What chromosome set is characteristic of vegetative, generative cells and sperm pollen grains of a flowering plant? Explain from what initial cells and as a result of what division these cells are formed. 23. Rabbit somatic cells contain 44 chromosomes. How will the number of chromosomes and DNA molecules in the nucleus change during gametogenesis before the start of division and at the end of the telophase of meiosis I? Explain the results in each case. 24. The somatic cells of the Drosophila fly contain 8 chromosomes. Determine the number of chromosomes and DNA molecules in cells during spermatogenesis in the reproduction zone and at the end of the gamete maturation zone. Justify your answer. What processes occur in these zones? 25.What chromosome set is characteristic of the spore, gametophyte and sporophyte of the cuckoo flax moss? From what initial cells and as a result of what division are these stages of moss development formed? 26.What chromosome set is characteristic of the flesh cells of pine needles and sperm cells? Explain from what initial cells and as a result of what division these cells are formed

27. The total mass of all DNA molecules in 46 chromosomes of one human somatic cell is about 6∙10−9 mg. Determine the mass of all DNA molecules in the cell nucleus during spermatogenesis before the start of meiosis and after the end of meiosis. Explain your results. 28. Signs that determine blood type and Rh factor are not linked. Blood group is controlled by three alleles of one gene – i0, IA, IB. Alleles IA and IB are dominant to allele i0. The first group (0) is determined by the recessive genes i0, the second group (A) is determined by the dominant allele IA, the third group (B) is determined by the dominant allele IB, and the fourth (AB) is determined by two dominant alleles IAIB. The positive Rh factor (R) dominates the negative Rh factor (r). The father has the second blood group and is Rh negative, the mother has the first group and is Rh positive (homozygous). Make a diagram for solving the problem. Determine the possible genotypes of the parents, possible blood groups, Rh factor and genotypes of the children. Explain your results. What law of heredity will manifest itself in this case? 29.What chromosome set is characteristic of vegetative, generative cells and sperm pollen grains of a flowering plant? Explain from what initial cells and as a result of what division these cells are formed. 30. The total mass of all DNA molecules in 46 chromosomes of one human somatic cell is about 6 × 10−9 mg. Determine the mass of all DNA molecules in the nucleus during spermatogenesis before the start of meiosis, after meiosis I and meiosis II. Explain your results. 31.The karyotype of a dog includes 78 chromosomes. Determine the number of chromosomes and the number of DNA molecules in cells during oogenesis in the reproduction zone and at the end of the gamete maturation zone. What processes occur in these zones? Justify your answer (the answer must contain four criteria). 32. The field mouse has 40 chromosomes. How many chromosomes does a male mouse have in the spermatogonia, from which sperm formation begins, in mature sperm and in the cells of the embryo? What division leads to the formation of these cells? What cells are they formed from? 33. There are 34 chromosomes in the karyotype of an apple tree. How many chromosomes and DNA will be contained in the apple egg, the endosperm cells of its seed and the leaf cells? From what cells are these cells formed? 34. The chromosome set of somatic potato cells is 48. Determine the chromosome set and the number of DNA molecules in cells during meiosis in prophase of meiosis I and metaphase of meiosis II. Explain all your results. 35. The mass of DNA molecules in somatic cells is 6*109. What is the mass of DNA molecules before the start of meiosis and in anaphase of meiosis 1? Explain your answer. 36. There are 42 chromosomes in the somatic cells of oats. Determine the chromosome set and the number of DNA molecules before the onset of meiosis I and in the metaphase of meiosis II. Explain your answer. 37. In Chlamydomonas, the predominant generation is the gametophyte. Determine the chromosome set of an adult organism and its gametes. Explain from which initial cells adult individuals and their gametes are formed, as a result of which division sex cells are formed. 38. The number of chromosomes in a somatic cell of Drosophila 8. Determine the number of chromosomes and DNA molecules in Drosophila during oogenesis in anaphase of meiosis 1 and prophase of meiosis 2. Explain the results. "Chargaff's Rule"

1. It is known that all types of RNA are synthesized on a DNA template. The fragment of the DNA molecule on which the tRNA section is synthesized has the following nucleotide sequence ATA-GCT-GAA-CHG-ACT. Determine the nucleotide sequence of the tRNA region that is synthesized on this fragment. Which mRNA codon will correspond to the anticodon of this tRNA if it transfers the amino acid GLU to the site of protein synthesis. Explain your answer. To solve the problem, use the table of the genetic code: 2. A gene contains 1500 nucleotides. One of the chains contains 150 nucleotides A, 200 nucleotides T, 250 nucleotides G and 150 nucleotides C. How many nucleotides of each type will there be in the DNA chain encoding a protein? How many amino acids will be encoded by this DNA fragment? 3. In one DNA molecule, nucleotides with thymine (T) make up 24% of the total number of nucleotides. Determine the number (in %) of nucleotides with guanine (G), adenine (A), cytosine (C) in a DNA molecule and explain the results obtained. 4. Given a DNA chain: CTAATGTAATCA. Determine: A) The primary structure of the encoded protein. B) The percentage of different types of nucleotides in this gene (in two chains). B) The length of this gene. D) The length of the protein. 5. Somatic cells of Drosophila contain 8 chromosomes. Determine how many chromosomes and DNA molecules are contained in nuclei during gametogenesis before division in interphase and at the end of telophase of meiosis I. Explain how such a number of chromosomes and DNA molecules are formed. 6. The specimen revealed tissues with the following structures: a) a layer of cells closely adjacent to each other, b) the cells are separated by a well-developed intercellular substance, c) the cells are highly elongated, and transverse striations are observed in them. Write which tissue each of these structures belongs to. 7. A fragment of an mRNA chain has the following nucleotide sequence: TSUATSAAGGTSUAU. Determine the sequence of nucleotides on DNA, the anticodons of the corresponding tRNAs and the amino acid sequence of the corresponding fragment of the protein molecule using the genetic code table. 8. The bracken fern sporophyte has 52 chromosomes. How many chromosomes does it have in the sporangial cells, in the mature spores and in the prothalla cells? What division leads to the formation of these cells? What cells are they formed from? 9. A fragment of the DNA nucleotide chain has the sequence CCATAGC. Determine the nucleotide sequence of the second strand and the total number of hydrogen bonds that form between the two DNA strands. Explain your results. “Energy metabolism” 1. Explain the similarities and differences between the biological oxidation of organic substances in a cell and the process of their combustion in inanimate nature.

2. In the process of glycolysis, 112 molecules of pyruvic acid (PVA) were formed. How many glucose molecules are broken down and how many ATP molecules are formed during the complete oxidation of glucose in eukaryotic cells? Explain your answer. 3. During the oxygen stage of catabolism, 972 ATP molecules were formed. Determine how many glucose molecules were broken down and how many ATP molecules were formed as a result of glycolysis and complete oxidation? Explain your answer. 4. During the oxygen stage of catabolism, 1368 ATP molecules were formed. Determine how many glucose molecules were broken down and how many ATP molecules were formed as a result of glycolysis and complete oxidation? Explain your answer.

1. In an animal cell, the diploid set of chromosomes is 34. Determine the number of DNA molecules before mitosis, after mitosis, after the first and second division of meiosis.

Solution: According to the condition, 2n=34.

Genetic set:

1. Before mitosis there is 2n4c, so there are 68 DNA molecules in this cell;
2. After mitosis 2n2c, so this cell contains 34 DNA molecules;
3. After the first meiotic division, n2c, so this cell contains 34 DNA molecules;
4. After the second meiotic division nc, therefore this cell contains 17 DNA molecules.