The cones and pollen are not themselves sexual organs. They also produce most of the primary hormones that affect sexual development, and regulate other sexual organs and sexually differentiated behaviors. Male the male reproductive system pdf female genitals have many nerve endings, resulting in pleasurable and highly sensitive touch.
The absence of it allows the gonads to continue to develop into ovaries. Furthermore, differences in brain structure arise, affecting, but not absolutely determining, behavior. Some parents allow their doctors to choose. A great variety of genital form and function may therefore be found among animals. Excretory systems with analogous purpose in certain invertebrates are also sometimes referred to as cloacae. There are sexual and asexual planaria.
Sexual planaria are hermaphrodites, possessing both testicles and ovaries. Each planarian transports its excretion to the other planarian, giving and receiving sperm. Any sex organs that are produced by the plant will develop on the gametophyte. Within each pollen grain is a male gametophyte which consists of only three cells.