Test: Gametogenesis & Menstrual Cycle

• Spermatogenesis is the process in which spermatozoa (male gametes) are formed from the primordial germ cells.
• Estrogen, progesterone are female sex hormones while oxytocin is the hormone which causes the uterus to contract during childbirth and stimulates the release of milk during nursing.
• Testosterone is the male hormone which is responsible for maintenance of male reproductive system.

Spermatogenesis​:

• The process of formation of a mature female gamete is called oogenesis.
• Unlike sperm formation that starts at puberty, egg formation begins before birth.
• Primordial germ cells complete the proliferative stage or oogenesis in the early embryonic stage when million of gamete mother cells (oogonia) are formed within each fetal ovary, no more oogonia are formed and added after birth. 

• The ovum is enclosed by the inner thin, transparent, non-cellular coat zona pellucida and outer thick coat corona radiata.
• During fertilization sperm first comes in contact with the corona radiata and zona pellucida to reach the plasma membrane of the egg(ovum).
• The figure represents Ovum.
  

• Menopause marks the end of a woman's fertility and the cease of the menstrual cycle.
• The ovaries stop producing hormones and in humans, the menstrual cycle ceases at around 50 years of age. 

1. Zygote is also diploid and fertilized ovum formed by fusion of male and female gametes.

2. Spermatogonia are the cells on the inside wall of seminiferous tubules and consist of 46 chromosomes.

3. Secondary oocyte has 23 chromosomes and is formed by meiosis-I of primary oocyte.

4. Oogonia are also diploid and are formed in the fetal ovary.​