Question

Penis is bifid in
a) Marsupials
b) Placentals
c) Both of the above
d) Prototherians

Answer 1

Hint: Penis bifid is a condition in which two penises are present instead of one. It is a rare congenital disorder. It is in association with an ecstrophia of the urinary bladder or due to abnormalities in the region of the urinary tract.

Complete answer:
In Marsupials, it can be seen as a characteristic feature of the male having a bifid penis. The females also have two vaginas present hence bifurcated penis can be used in the vaginas. They also have a distinct character of keeping their young ones in the pouch. They are only found in the Australian region due to geographical isolation. In marsupials, the young ones when born are not well nourished hence they are kept in the pouches present in the female. They then grow in the pouch and when they are strong enough, they are removed from the pouch.

Additional information: Placentals are the most diverse group of mammals. They don’t have a bifurcated penis. The most distinctive feature of the placental is that the mother carries the child in the uterus and feeds it through the placenta. The placenta in the uterus is the only source through which the developing embryo is nourished when inside the womb. Hence, the name placentals. They include all the living mammals excluding marsupials and monotremes. Humans can be categorized under placentals as they have placenta present and bear live young ones.
- Prototherians are egg-laying mammals. They are limited to the Australian region. They are under mammals as they have the presence of notochord in some part of their life cycle. Testes are abdominal.
So, the answer is ‘a) Marsupials’.

Note: Bifid penis is present in the kangaroos. They are present to fertilize the female from the kangaroos two vaginas present in them. In humans, if a bifid penis is present it may be due to some disorder or due abnormality.