ICSE solutions for Biology [English] Class 10 chapter 2 - Fundamentals of Genetics [Latest edition]

What is a gene? How is it related to heredity?

Define the term Mutation.

 Give the significance of mutation.

What is crossing-over? What are the factors affecting it?

Why did Mendel select pea plants for his experiment?

Define Mendel’s law of segregation.

What is a monohybrid cross? How did Mendel perform this cross?

A certain couple got four daughters in a sequence and no son. Does it mean that the husband does not produce Y-chromosome bearing sperms? Explain. What is the chance of this couple having a daughter?

Mutation alerts the hereditary material. Give reasons.

Why do men suffer from hemophilia and colour blindness? Under what conditions do women suffer from these disorders?

Give Reason:

 The Law of independent assortment holds good for the gene pairs that occur in different pairs of chromosomes.

Give Reason:

Heritable variations are called genetic variations.

Give Reason:

Discontinuous variations are inheritable.

Give Reason:

Why X-linked recessive diseases are more common among males than females.

Give Reason:

In the honey bee, the female is diploid and the male is haploid.

Give Reason:

Hemophilia shows criss-cross inheritance.

Differentiate Between Homozygous shows Heterozygous.

Differentiate Between Y-linked inheritance and X-linked inheritance.

Differentiate Between Haemophilia and Colour blindness.

Differentiate Between Genotype and Phenotype.

Differentiate Between  Monohybrid and Dihybrid cross.

State Mendel’s Law of Dominance.

A pure tall plant (TT) is crossed with a pure dwarf plant (tt).
Draw Punnet squares to show
(1) F₂ generation
(2) F₂ generation.

Give the Phenotype of the F₂ generation.

Give the Phenotypic and Genotypic ratio of the F₂ and F₂ generation.

Name anyone X-linked disease found in humans.

Write a short note on sex determination in man.

 A woman with normal vision marries a man with normal vision. They have a colourblind son. Her husband dies and she marries a colourblind man. Show the type of children that might be expected from this marriage and the proportion of each.

What is a dihybrid cross? How did Mendel perform this cross?

A woman had normal vision, but her father was colourblind. She marries a man, who is colourblind.
Find out the probability of the first child being colourblind, whether it is a boy or girl.

The karyotype (set of chromosomes) shown below is taken from a dividing cell in a certain individual.
(i) Is the individual male or female? Explain your answer.
(ii) How would you expect
(a) a female cell and
(b) sperm cell to differ in chromosome composition?

State Mendel’s law of Independent Assortment.

A homozygous Tall plant (T) bearing red coloured (R) flowers is crossed with a homozygous dwarf plant (t) bearing white flowers (r):
(1) Give the Genotype and Phenotype of the F₂ generation.
(2) Give the possible combinations of the gametes that can be obtained from the F₂ hybrid.
(3) Give the dihybrid ratio and the phenotype of the offsprings of the F₂ generation when two plants of the F₁ generation above are crossed.

A haemophilic man marries a carrier women. Find out the probability of their offsprings being haemophilic.

Given below is a schematic diagram showing Mendel’s Experiment on sweet pea plants having axial flowers with round seeds (AARR) and Terminal flowers with wrinkled seeds (aarr). Study the same and answer the questions that follow :

(i) Give the phenotype of F₁ progeny.
(ii) Give the phenotypes of F₂ progeny produced upon by the self-pollination of F₁ progeny.
(iii) Give the phenotypic ratio of F₂ progeny.
(iv) Name and explain the law induced by Mendel on the basis of the above observation.

Explain the Term Heredity.

Explain the Term Variation.

Explain the Term Dominance.

Explain the Term Linkage.

Explain the Term Mutation.

Explain the Term Crossing-over.

Explain the Term Heterosome.

Explain the Term Recessive character.

Explain the Term Genotype.

Explain the term Alleles.

Name the following:

The study of heredity and variation.

Name the following:

Cells having a single set of chromosomes.

Name the following:

The genetic composition of an organism.

Name the following:

Pairs of chromosomes, present in human egg cells.

Name the following:

The number of chromosomes present in human gametes.

Name the following:

The diploid number for cell of man.

Name the following:

Chromatids where Recombination of characters occurs.

Name the following:

A specific part of a chromosome that determine hereditary characteristics.

Name the following:

The pattern of arrangement of genes along a chromosome.

Name the following:

Pair of genes responsible for a particular characteristic.

Name the Following

The type of gene which is not expressed in the presence of a contrasting allele.

Give Technical Term:

Transmission of characters through generations.

Give Technical Term:

Differences occurring within offsprings of the same progeny.

Give Technical Term:

Cell organelle directly involved in genetics.

Give Technical Term:

The cell which determines the sex of a baby.

Give Technical Term:

A virus with DNA as heredity material.

Give Technical Term:

The hereditary unit, which is responsible for inheritance.

Give Technical Term:

Transmits characteristics from parents to offsprings.

Give Technical Term:

The individual having similar pair of genes.

Give Technical Term:

The individuals having dissimilar pairs of genes.

Give Technical Term:

The ratio of offspring on F2 generation in a dihybrid cross.

Give Technical Term:

A single egg was fertilized by a single sperm. But twins derived from that egg were born. What is the name of such type of twins?

Give Technical Term:

A twin consisting of a brother and a sister were born to a lady. What is the name of such a type of twins?

Give Technical Term:

Name a genetic disease in which a person cannot distinguish red and green colour.

Complete the following sentence with appropriate word:

The chromosomal theory of inheritance was proposed by ____________in 1902.

Complete the following sentence with appropriate word:

______is the hereditary unit.

Complete the following sentence with appropriate word:

In mammals, the female is homozygous while the male is _________.

Complete the following sentence with appropriate word:

A chromosome is composed of 50 % DNA and 50% ________.

Complete the following sentence with appropriate word:

___________ is the Father of Genetics.

Complete the following sentence with appropriate word:

The number of chromosomes in humans is ________.

Complete the following sentence with appropriate word:

The physical expression of genes is called _________.

Complete the following sentence with appropriate word:

The small differences among individuals are called ________.

Complete the following sentence with appropriate word:

The dissimilar pairs of genes present in an individual are known as _______________.

Complete the following sentence with appropriate word:

___________ chromosomes do not take part in sex determination.

Complete the following sentence with appropriate word:

______are the alternative forms of a gene producing different effects.

Complete the following sentence with appropriate word:

_______ is the ratio of dihybrid cross.

Complete the following sentence with appropriate word:

A character that is suppressed is _________.

Complete the following sentence with appropriate word:

Upon _______the diploid condition is restored.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Most genetic diseases in man are recessive in character.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

DNA has a double-helical structure.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Genes are responsible for genetic characters.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Linkage is a permanent feature of few genes.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Mutation can be brought about artificially.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

A female is responsible for the sex of the progeny.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Mendel experimented upon plants of Oryza sativa.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

 Male act as a carrier for colourblindness.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Females are more affected by sex-linked genetic disorders.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Colour blindness is a Y-linked character.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Haemophilia exhibits X linked inheritance.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

A colourblind male cannot distinguish any colour.

Mention, if the following statement is True or False. If false rewrite the wrong statement in its correct form:

Cancer is a genetic disorder.

Write the functional activity of the following structure:

DNA

Write the functional activity of the following structure:

Chromosomes

Write the functional activity of the following structure:

Genes

Write the functional activity of the following structure:

Autosomes

Write the functional activity of the following structure:

Heterosomes

Choose the Odd One Out

Choose the Odd One Out

Choose the Odd One Out

Choose the Odd One Out

Multiple Choice Question

Genetics is a branch of biology dealing with:

Multiple Choice Question

Who among the following is called father of genetics?

Multiple Choice Question

When an individual has both the genes of a contrasting character, it is said to be:

Multiple Choice Question

When two individuals differing in at least one character are crossed, the process is known as:

Multiple Choice Question

A cross was made between tall and dwarf plants. In F1 generation all plants were tall, when the F1 plants were selfed, the tall and dwarf plants appeared in a 3 : 1 ratio in the F2 generation. This phenomenon is known as:

Multiple Choice Question

What is the effect of sexual reproduction?

Multiple Choice Question

DNA structure was discovered by:

Multiple Choice Question

Chromosomal aberrations are caused by:

Column ‘II’ is a list of items related to ideas in Column ‘I’. Match the term in Column ‘II’ with a suitable idea given in Column ‘I’.