Question

Give the gender (male, female, meta-male, meta-female) and number of Barr bodies (where asked) for the following organisms with the indicated karyotypes. Assume:

A = a full haploid set of autosomes

M = male

F = female

I = intersex / indeterminate meta-F = meta-female

meta-M = meta-male

T = Turner’s Syndrome

K = Kleinfelter’s Syndrome:

__________ (M / F) A crocodile displaying the gender determination curve shown above, assuming cold temperatures (assume most likely outcome) __________ (M / F) A haploid ant.

__________ (M / F) An insect with gender chromosome X under the Protenor model

__________ (M / F) An insect with gender chromosome XX under the Protenor model

__________ (M / F / meta-M / meta-F) A fruit fly with chromosomes XXX/2A

Answer 1

1, Cold temperature (low temperature) induces femaleness in crocodile and vice versa. So outcome in cold temperature will be F i.e., Female.

2. A haploid ant will be Male.

2. An insect with gender chromosome X under the Protenor model will be M i.e., Male. Males are heterogametic.

3.An insect with gender chromosome XX under Protenor model will be F i.e., Female . Females are homogametic.

4.A fruit fly ( Drosophila) with chromosome XXX/2A will be Meta - F i.e., Meta female / super female.

Barr Body:

Barr body can be easily calculated by using below formula:

No. of Barr body = (No. of X chromosomes - 1).