Reproduction System

The gestation period is the period of foetal development starting from fertilisation and ending at parturition or childbirth. During this period, the single-celled zygoteundergoes gradual changes that help it to become afunctional multicellular organism. The gestation period in human beings is about 270-280 days (9 months).

Vas deferens is a part of the male reproductive system. It is a duct that carries sperms from epididymis to copulatory organ. Along the way, secretions from seminal vesicles and prostate glands are added to the sperms. Ovary, uterus, fallopian tubes are parts of the female reproductive system.

Hydra and yeast can reproduce by budding. Amoeba reproduces by fission. Lizard does not reproduce by asexual reproduction. Spirogyra reproduces by fragmentation.

The process of doubling and replicating the genetic material in the human cells is known as DNA replication and meiotic cell division reduces chromosome number to half in sex cells. DNA replication is essential for cell division to take place.

Pollination is the transfer of pollen grains from the anther of one flower to the stigma of the same or another flower. Pollen grains contain the male gamete and are present in the anthers of the flower. If the pollen grains land on the sticky surface called stigma of a suitable flower of the same species, a chain of events happen that ends in the development of seeds. The pollen grain on the stigma, grows a tiny tube, all the way down the style to the ovary. The ovary develops into a fruit after fertilisation.

One pair of ovaries and testis are present in human females and males respectively. Ovaries produce ovum and sperm is produced by the testis. Ovum is the female gamete and sperm is the male gamete. Ovum and sperm fuse to form the zygote.

The egg cell, or ovum (plural ova), is the female reproductive cell (gamete) in sexually producing organisms. The egg cell is typically not capable of active movement, and it is much larger (visible to the naked eye) than the sperm. The motile germ cell is sperm. The primary function of the sperm is to pass on the necessary biological information required to produce a new organism. This is true for all the organisms which reproduce sexually.

Ovum or ova is the female gamete produced by the ovaries. It is a non-motile structure larger than a sperm. It is a single, haploid cell with several protective layers outside its cell membrane.

Vasectomy is a surgical procedure for male sterilisation and/or permanent contraception. During the procedure, the male vasdeferens are severed and then tied/sealed in a manner so as to prevent sperms from entering into the seminal stream (ejaculate) and thereby preventing fertilisation. Tubectomy is asimilar process in females where the fallopian tube is sealed. Hysterectomy is theremoval of uterus which is carried out only is severe disease conditions. Mastectomy is the medical term for the surgical removal of one or both breasts, partially or completely.