Question

Which of the following statements are correct regarding chromosomal basis of sex determination?

i. The mechanism of sex determination in insect is XX - XO type.

ii. In honey-bee, haplo-diploid type of sex determination is observed.

iii. Human males have homomorphic sex chromosomes.

iv. Human females have heteromorphic sex chromosomes.

v. Chromosomal mechanism of sex determination in birds is ZW-ZZ type.

• A. i, ii and v only
• B. iii and iv only
• C. i, ii and iv only
• D. ii, iv and v only

Hint:

Check each of the five statements separately.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept
Sex determination mechanisms differ between organisms.

Step 2: Check each statement
(i) true: grasshopper and other insects show XX-XO type.
(ii) true: honey bee shows haplo-diploid type.
(iii) false: human males have XY, which are heteromorphic.
(iv) false: human females have XX, which are homomorphic.
(v) true: birds show ZW-ZZ type.

Step 3: Compare the options
Statements i, ii and v are correct.

Final Answer:
Only statements i, ii and v are correct. \[ \boxed{\text{(A) }\text{i, ii and v only}} \]