- Home
- Standard 12
- Biology
4.Principles of Inheritance and Variation
normal
Barr body in mammals represents
A
All the heterochromatin in female cells
B
One of the two $X$ chromosomes in somatic cells of females
C
All the heterochromatin in male and female cells
D
The $Y$ chromosome in somatic cells of male
(AIPMT-1995)
Solution
(b)Barr body is nothing but ‘$X$’ chromosome which has become heterochromatic, thus appear as deeply stained body. Of the two ‘$X$’ chromosomes are remains normal while the other appears as a Barr body.
Standard 12
Biology
Similar Questions
In Drosophila, the allele for a normal grey body colour $G$ is dominant to ebony body $g.$ The following table summarises the results of several crosses
| S.No | Cross | Result |
| $I.$ | Strain $1 \times$ gg | All wild type |
| $II.$ | Strain $2 \times$ gg |
$1$ wild type $:\;1$ ebony |
| $III.$ | Strain $3 \times$ gg | All ebony |
| $IV.$ | Strain $4 \times$ Gg |
$3$ wild type $:\,1$ ebony |
Which strains both have the genotype Gg?
normal
