Genetics Class 10 Concise Descriptive Type Ans ICSE Biology Selina Solutions

Genetics Class 10 Concise Descriptive Type Ans ICSE Biology Selina Solutions Ch-3. In this article you will get the solutions of Descriptive Type Questions as council latest syllabus. Visit official website CISCE for detail information about ICSE Board Class-10 Biology.

Genetics Class 10 Concise Descriptive Type Ans ICSE Biology Selina Solutions

Board	ICSE
Subject	Biology
Class	10
Book	Selina Concise
Chapter-3	Genetics: Some Basic Fundamentals
Topics	Solutions of Descriptive Type Questions
Session	2024-25

Descriptive Type Questions on Genetics

Class 10 Concise ICSE Biology Selina Solutions Ch-3 Genetics: Some Basic Fundamentals

Que-1: Define the following terms:

(a) Pedigree chart

(b) Variations

Sol:

(a) Pedigree chart — Symbolic representation that shows the occurrence and appearance or phenotypes of a particular gene or organism and its ancestors from one generation to the next.

(b) Variations — The small but observable differences among the individuals of the same species are called variations.

(c) Mutation — sudden change in one or more genes, or in the number or in the structure of chromosomes. Mutation alters the hereditary material of an organism’s cells and results in a change in certain characters or traits for example :

Sickle cell anaemia
Radioactive radiations

Que-2: State the three Mendel’s laws of inheritance.

Sol: Mendel’s law of inheritance are as follows —

Law of Dominance — Out of a pair of contrasting characters present together, only one is able to express itself while the other remains suppressed. The one that expresses is the dominant character and the one that is unexpressed is the recessive one.
Law of Segregation (also called the law of purity of gametes) — The two members of a pair of factors separate during the formation of gametes. They do not blend but segregate or separate into different gametes. The gametes combine together by random fusion at the time of zygote formation.
Law of Independent Assortment — When there are two pairs of contrasting characters, the distribution of the members of one pair into the gametes is independent of the distribution of the other pair.

Que-3: Does the sex of the child depend on the father or is it just a matter of chance? Discuss.

Sol: The sex of the child depends upon the kind of sperm that fertilises the egg. The egg contains only one X chromosome, but half of the sperms released into the genital tract of the female during coitus are X-bearing and the remaining half are Y-bearing. It is simply a matter of chance as to which category of sperm fuses with the ovum:

If the egg (X) is fused by X-bearing sperm, the resulting combination is XX i.e. female constitution and the child produced is a female (Daughter).
If the egg (X) is fused by Y-bearing sperm, the resulting combination is XY i.e. male constitution and the child produced is a male (Son)

Que-4: Distinguish between the following pairs:

(a) Karyotype and Karyokinesis

(b) Autosomes and Sex chromosomes

Sol:

(a) Difference between karyotype and karyokinesis —

Karyotype	Karyokinesis
The complete set of chromosomes in the cells of an organism is its karyotype.	division of the nucleus during mitosis is called karyokinesis.

(b) Difference between autosomes and sex chromosomes

Autosomes	Sex chromosomes
determine the somatic traits.	They determine the sex of an organism.
numbered as 1 to 22.	recognized by the letters XO, XY, ZO, ZW.
show Mendelian inheritance.	do not show Mendelian inheritance.
Human show 22 pairs of autosomes.	Humans show only 1 pair of sex chromosome.