ADAPTATIONS OF GAMETES

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Adaptive features of the sperm.
  1. The head is oval thus making it streamlined hence can easily swim faster.
  2. The head has an acrosome which contains lytic enzymes that dissolve the egg membrane during fertilization.
  3. The head has a large haploid nucleus which carries the male genetic materials.
  4. The neck has centrioles which form axial filaments for movement.
  5. The middle piece has numerous mitochondria and respiratory enzymes to produce energy for swimming.
  6. The middle piece has axial filaments that enable the tail to lash from side to side thus propelling it.

Adaptive features of the egg.
1. Haploid nucleus that carries genetic materials in the form of chromosomes.
2. The cytoplasm contains organelles such as centrioles, mitochondria, golgi bodies, rough endoplasmic reticulum. It also contains food reserves in the form of yolk proteins which provides nutrients during the early stages of development.
3. Vitelline membrane.
Located just above the plasma membrane. It prevents the entry of more sperms once the first one has entered.
4. Zona pellucida.
It is a jelly-like glycoprotein which prevents the entry of sperms from different species.
5. Corona radiata.
Contains a layer of follicle cells that provide nourishment during development in the ovary. In addition, the cells also protect the egg until fertilization.

Comments

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