Selina solutions for Concise Biology [English] Class 10 ICSE chapter 3 - Genetics: Some Basic Fundamentals [Latest edition]

Which one of the following is the phenotypic monohybrid ratio in F₂ generation?

If a pure tall plant is crossed with a pure dwarf plant, then offspring will be ______.

The 9 : 3 : 3 : 1 dihybrid ratio is due to ______.

A plant with green pods and smooth seeds with the genotype Ggss will give rise to the following gametes:

The disease colour blindness is a ______.

The physical expression of a character is called ______.

Purity of gametes is linked to ______.

The phenotypic dihybrid ratio of F₂ generation is ______.

In the human male, a sperm contains autosomes and ______.

If the mother is normal and the father is haemophilic, then their two daughters will be ______.

Match the terms in column I with their explanations in column II. 

Name any two genetic diseases in humans.

Which one of the following genotypes is homozygous dominant and which one homozygous recessive in regards to tongue rolling:

Rewrite the correct form of the statement by changing the first or last word only:

Duplicated chromosomes remain attached at a point termed as centrosome.

Rewrite the correct form of the statement by changing the first or last word only:

The full complement of DNA of an organism is termed as genetics.

Rewrite the correct form of the statement by changing the first or last word only:

The inheritable feature of an organism is termed as heredity.

Rewrite the correct form of the statement by changing the first or last word only:

Terminal flower position is a dominant trait of pea flower.

Rewrite the correct form of the statement by changing the first or last word only:

Alternative forms of a gene are called traits.

Among lion, tiger and domestic cat, all three have the same number of 38 chromosomes, yet they have different appearances. How do you account for such differences ?

List any three features of garden pea with their dominant and recessive traits. 

Explain why generally only the male child suffers from colour blindness and not the female?  

Define the following term:

Pedigree chart

Define the following term:

Variations

Define the term Mutation.

State the three Mendel’s laws of inheritance. 

Does the sex of the child depend on the father or it is just a matter of chance? Discuss. 

Distinguish between the following pair:

Karyotype and Karyokinesis

Distinguish between the following pair:

Autosomes and Sex chromosomes

Distinguish between the following pair:

Homozygous and Heterozygous chromosomes

In a certain species of animals, black fur (B) is dominant over brown fur (b) Predict the genotype and phenotype of the offspring when both parents are ‘Bb’ or have heterozygous
black fur . 

Two pairs (A & B) of rabbits were crossed, as given below: 

1. Can you tell which coat colour (black or white) is dominant?
2. Is the coat colour sex-linked?

Make a Punnett square and find out the genotypic and phenotypic ratios of F₂ generation in the progeny of a genetic cross between:

1. A pure tall (TT) pea plant with a pure dwarf (tt) pea plant.
2. Red flower variety of pea (RR) with white flower variety of pea (rr).

Mendel crossed a homozygous pea plant having round seeds (RR) with a homozygous pea plant having wrinkled seeds (rr). He got different results. On the basis of it, answer the following questions:

1. Which character of seed is studied in the experiment?
2. Which of the above two traits is dominant?
3. Write the phenotype and genotype of F₁ offspring.
4. Mention and state Mendel's law as shown in the above cross.
5. Make a Punnett square for F₂ generation when two plants of F₁ offspring are crossed with each other.
6. Write the phenotypic ratio of F₂ progeny.
7. What will be the genotypic ratio of F₂ offspring?
8. What are the two traits of seed colour ? Also mention which is dominant and recessive?
9. Write the scientific name of the garden pea.
10. Write two main features of the pea plant, due to which Mendel selected it for his hybridisation studies.

A homozygous plant having round (R) and yellow (Y) seeds is crossed with another homozygous plant having wrinkled (r) and green (y) seeds. Answer the following questions:

1. Give the genotype of the F₁ generation.
2. Mention the phenotype of the F₁ offspring.
3. Give the possible combinations of gametes that can be obtained from F₁ hybrids.
4. Give the dihybrid phenotypic ratio and the phenotype of the offspring of the F₂ generation when two plants of F₁ generation are crossed.
5. Name and state the law which explains the dihybrid phenotypic ratio.