What will you look for to identify the sex of the following?
- Female Ascaris – sharply curved posterior end
- Male frog – a copulatory pad on the first digit of the hind limb
- Female cockroach – anal cerci
- Male shark – claspers borne on pelvic fins
Answer
(4) Male shark – claspers borne on pelvic fins
Solution
∵ In Ascaris the male (not the female) has a sharply curved posterior end ⇒ (1) is wrong.
∵ The male frog has a copulatory pad on the first digit of the fore limb ⇒ (2) is wrong.
∵ Anal cerci are present in both sexes of cockroach; only males bear anal styles ⇒ (3) is wrong.
As per NCERT, in cartilaginous fishes the pelvic fins of males bear claspers ⇒ (4) is right.
Answer: (4)