5
votes
1answer
88 views

Why are there so many sex determining systems in animals

There are several sex determining systems in animals. In mammals XY = male(except in rare cases where SRY crosses with genes on the X so that it is the reverse) and XX = female. In some birds it is ...
2
votes
2answers
267 views

How to know if a woman is fertile without actually making her pregnant?

How to know if a human female is fertile (can give birth to child in future) without making her pregnant? Any signs, tests?
4
votes
1answer
123 views

How does sex differentiation work in Paracerceis sculpta, the sexually tetramorphic isopod?

Paracerceis sculpta is a marine isopod species known for its unusual reproductive strategy: female: medium-sized; lives in harems run by an α male α male: large; keeps a harem of females β male: ...
13
votes
1answer
471 views

How do porcupines keep from pricking each other while mating?

How do porcupines keep from pricking each other while mating? It seems like they would constantly be scratching each other.
11
votes
1answer
297 views

How do members of cryptic species know who to mate with?

According to Wikipedia: In biology, a cryptic species complex is a group of species which satisfy the biological definition of species—that is, they are reproductively isolated from each ...