Males and females have sex organs for making new organisms {reproduction, animal}.
day length
In some birds and small mammals, reproduction cycles depend on number of daylight hours.
sex among humans
Only human females are always ready for sex, have permanent breasts, have continuous ability to have orgasms, have active roles in sexual activities, and are similar in size to males. Human sex can be face to face. Humans have wide territories. Humans have foreknowledge of children. Humans typically do not allow incest, so no old males can dominate female groups. Humans do not have estrus and so do not know exactly when they ovulate. People can have more children almost immediately after having a child, whereas apes wait five to six years between births.
Biological Sciences>Zoology>Organ>Reproduction
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Date Modified: 2022.0224