monohybrid cross

Task 1.

In the Iranian dog, the gene for normal vision dominates the gene for blindness. After crossing a female and a male with normal vision in a litter of four puppies, one turned out to be blind. Determine the genotypes of parents and offspring.

Dihybrid cross

Task 2

In humans, brown-eyedness dominates over blue-eyedness, and right-handedness –

over left-handedness. Brown-eyed left-hander married a blue-eyed woman –

right-handed. They had a blue-eyed left-handed child. Determine the genotypes of parents and children.

Task 3

In humans, a free earlobe (A) dominates over a non-free one (a) , and a chin with a triangular fossa (B ) dominates over a smooth chin (c) . A man has a loose earlobe and a chin with a triangular fossa, while a woman has a loose earlobe and a smooth chin. They had a son with a loose earlobe and a smooth chin. Solve the problem using the Punnett lattice.

A) How many types of gametes does a man produce?

B) How many different phenotypes can children in this family have?

B) How many different genotypes can children in this family have?

D) What is the probability of having a baby with a free earlobe and a smooth chin?

E) What is the probability of having a child with a triangular fossa on the chin?

E) What is the probability that recessive homozygotes will be born in this family twice in a row?

G) What is the probability that recessive homozygotes will be born in this family four times in a row?

sex-linked inheritance

Task 4

Phenotypically healthy parents have two healthy daughters and a son with hemophilia. The hemophilia gene is located on the X chromosome. What are the genotypes of parents and children?

test questions

1. What does genetics study?

2. Who is the founder of genetics?

3. What is the essence of the law of uniformity of hybrids of the first generation?

4. What genes are called allelic?

5. What genes are called non-allelic?

6. What is the essence of the splitting law?

7. What are alternative features?

8. What is the essence of the law of independent inheritance of traits?

9. What is the meaning of the expression “the trait is sex-linked”?

Practice #4

“Identification of adaptations in organisms to the environment”

Purpose: to learn to identify the features of the adaptability of organisms to the environment and establish its relative nature.

Equipment: herbarium plant specimens, indoor plants, stuffed animals or drawings of animals from various habitats.

Working process

1.Determine the habitat of the plant or animal proposed to you for research. Identify the features of its adaptation to the environment. Reveal the relative nature of fitness. Enter the data obtained in the table “The fitness of organisms and its relativity.”

Fitness of organisms and its relativity

Table 1 *

species name Habitat Habitat adaptation traits What is the relativity of fitness

2. After studying all the proposed organisms and filling in the table, based on knowledge of the driving forces of evolution, explain the mechanism for the emergence of adaptations and write down the general conclusion.

test questions

1. What is the importance of the adaptability of organisms to the environment?

2. What are the mechanisms for the emergence of adaptive coloration in animals?

3. Does the action of natural selection extend to the behavior of animals?

4. How to explain the relative nature of fitness?

5. What is the essence of mimicry?

6. How do desert dwellers adapt to the lack of water?

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