In binary fission, the organism is divided into two daughter organisms. Amoeba reproduces by binary fission.

Fusion of male and female gametes takes place in sexual reproduction. 

Organisms of higher level of organisation like rat, dog, humans, etc. reproduce sexually.

Hydra reproduces asexually by budding. In budding, a bud (bulge) grows from the organism to form the daughter organisms. 

The fusion of male and female gametes is called fertilization.   

In Spirogyra, the offsprings are formed by the process of fragmentation. In fragmentation, the parent organism is broken into small fragments, and each fragment is capable of reproducing new offspring/organism of the same kind.

Uterus is the female reproductive organ, where the zygote matures and grows till it is ready to be born. 

Urethra is a tube inside the penis through which semen and urine pass out of the body. 

Testosterone is the male sex hormone, which is produced inside the testis. 

Male gamete is called sperm, which fuses with an ovum to produce a new organism. 

Penis transfers the semen and with it the sperms into the female body. 

The ovary is an endocrine gland. There are two ovaries in a female body. Each ovary has the shape and a size almost that of an almond.

The testis is an endocrine gland in male body. The testes are stimulated by the pituitary gland to produce male gametes, i.e. sperms.

A single sperm fuses with the ovum in the oviduct, and fertilization takes place.  

The fusion of male and female gametes takes place in oviduct (fallopian tube). 

Uterus is the organ where the zygote matures and grows till it is ready to be born.