Ovules are relatively large, motionless, round-shaped cells. In some fish, reptiles and birds, they contain a large supply of nutrients in the form of yolk and have sizes from 10 mm to 15 cm. The eggs of mammals, including humans, are much smaller (0.1-0.3 mm) and the yolk is practically do not contain. Spermatozoa are small mobile cells, in humans their length is only about 60 microns. In different organisms, they differ in shape and size, but, as a rule, all spermatozoa have a head, neck and tail, which ensures their mobility. In the sperm head is the nucleus containing the chromosomes, and the acrosome is a special vial with the enzymes necessary to dissolve the egg membrane. Mitochondria are concentrated in the neck, which provide the moving sperm with energy of only about 60 microns in length.
The ovum has:
– the presence of a large amount of yolk (nutrients of the future embryo)
-the presence of egg shells
-Sperm cells have:
– small sizes
-various forms in different mammals
-organ of movement (flagella from 1 to several)
– a large number of mitochondria
– the absence of ribosomes and EPS, a modified Golgi apparatus.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.