Question

In oogamous reproduction,
A) Both male and female gametes are motile
B) Both gametes are product of division of protoplast
C) Both male and female gametes are non-motile
D) For male gametes protoplast divides but for female gametes it does not

Answer 1

The fertilization process takes place through the fusion of male and female gametes, the two gametes are fused to form zygote, the zygote then undergo development and form the fetus. The fetus is developed into a young one.

Complete Answer:
- Reproduction is the fertilization of male sperm and female egg gets fused to form zygote that develops into a fetus inside the uterus. During this process the semen that ejaculates by the males while sexual intercourse comprise thousands of sperm cells.
- The sperm moves towards the uterus and reaches to the fallopian tube opening. From the thousand of sperm few only can reach the fallopian tube.
- Now, the secondary oocytes produced from the mature graafian follicle of the ovary enter inside the fallopian tube where it gets fertilized and released from the ovary.
- The oocyte is surrounded by several sperms but it gets fertilized only by one sperm. The sperm enter in the secondary oocyte in meiosis II phase and completes the meiosis this results in the formation of egg. After this phase, within 48 to 72 hours the sperm and the egg fused and form the zygote
- Now, oogamy is a sexual reproduction system in which the female gametes that is the egg is large and nonmotile and the male gametes that is the sperm cell is motile and small. It is a type of anisogamy.
- During the spermatogenesis process, the protoplast of sporangium is divided equally into four spermatids but during oogenesis, the ovum retains the protoplast bulk and shares the polar bodies.

Thus, the correct option is ‘D’. For male gametes protoplast divides but for female gametes it does not.

Note: Another sexual reproduction system is isogamy, the isogamy involves the gametes of similar shape and size but different in the expression of allele in more than one region. This type of reproduction is found in fungi and algae.