Hydra reproduces by budding.

Stamens and carpels are reproductive parts of a flower, which contain germ cells.

Birth control pills, use of mechanical barriers and blocking of fallopian tubes or vas deferens are contraceptive methods.

Bacterial infections such as gonorrhoea and syphilis, and viral infections such as warts and HIV AIDS are sexually transmitted diseases.

Organisms look similar because their body designs are similar.

Planaria can be cut into any number of pieces and each piece grows into a complete organism. This is known as regeneration.

The chromosomes in the nucleus of a cell contain information for inheritance of features from parents to the next generation in the form of DNA (Deoxyribo Nucleic Acid) molecules.

Two different types of gametes give rise to differences in the male and female reproductive organs and in some cases, differences in the bodies of the male and female organisms.

Transfer of pollen from anther to stigma is called pollination. Each pollen grain is a male haploid gametophyte, adapted to being transported to the female gametophyte, where it can effect fertilisation by producing the male gamete (or gametes, in the process of double fertilisation). 

Ovary in females and testis in males are the primary sex organs in humans.

The germ cells are called gametes. In humans, sperms are the male gametes and ovum is the female gamete.

The formation of germ cells or sperms takes place in the testes.

The sperm enters through the vaginal passage during sexual intercourse. It travels upwards and reaches the oviduct where it may encounter the egg.

Menstrual cycle starts at puberty in human female.

The main advantage of vegetative propagation is that all plants produced by this method are genetically similar enough to the parent plant to have all its characteristics.