Principles of Inheritance and Variation Question 137
137. Match the items of Column-I with Column-II :
| Column-I | Column-II |
|---|---|
| (A) XX-XO method | (i) Turner’s syndrome of sex determination |
| (B) XX-XY method | (ii) Female heterogametic of sex determination |
| (C) Karyotype-45 | (iii) Grasshopper |
| (D) ZW-ZZ method of sex | (iv) Female homogametic determination |
Select the correct option from the following :
(a) (A)-(iv), (B)-(ii), (C)-(i), (D)-(iii)
(b) (A)-(ii), (B)-(iv), (C)-(i), (D)-(iii)
(c) (A)-(i), (B)-(iv), (C)-(ii), (D)-(iii)
(d) (A)-(iii), (B)-(iv), (C)-(i), (D)-(ii)
Show Answer
Answer : d
Hints & Solution
(d) XX- XO type of sex determination is seen in crickets, grasshoppers, and some other insects. In all these organisms the female is $XX$ and is the homogametic sex. The male is the heterogametic sex but only has one sex chromosome. The male in XX-XO systems produce gametes with $(X)$ or without $(O)$ a sex chromosome.
In XX - XY method of sex determination, the sex of an individual is determined by a pair of sex chromosomes. Females typically have two of the same kind of sex chromosome (XX), and are called the homogametic sex. Males typically have two different kinds of sex chromosomes (XY), and are called the heterogametic sex. Turner’s syndrome is also known as $45, X$ or 45 , X,. It is a condition that affects only females, and results when one of the $X$ chromosme (sex chromosomes) is missing or partially missing. ZW-ZZ method of sex determination can be seen in some birds, butterflies, moths, and other organisms. Instead of X and Y chromosomes, they have $Z$ and $W$ chromosomes. The female is the heterogametic sex. In all these organisms female has a pair of dissimilar ZW chromosomes and male has two similar ZZ chromosomes.
