How Do Organisms Reproduce?

What you will learn

• Reproduction, unlike other life processes, is not essential to maintain the life of an individual organism.

• Reproduction involves creation of a DNA copy and additional cellular apparatus by the cell involved in the process.

• Various organisms use different modes of reproduction depending on their body design.

• In fission, many bacteria and protozoa simply divide into two or more daughter cells.

• Organisms such as hydra can regenerate if they are broken into pieces. They can also give out buds which mature into new individuals.

• Roots, stems and leaves of some plants develop into new plants through vegetative propagation.

• These are examples of asexual reproduction where new generations are created from a single individual.

• Sexual reproduction involves two individuals for the creation of a new individual.

• DNA copying mechanisms creates variations which are useful for ensuring the survival of the species. Modes of sexual reproduction allow for greater variation to be generated.

• Reproduction in flowering plants involves transfer of pollen grains from the anther to the stigma which is referred to as pollination. This is followed by fertilisation.

• Changes in the body at puberty, such as increase in breast size in girls and new facial hair growth in boys, are signs of sexual maturation.

• The male reproductive system in human beings consists of testes which produce sperms, vas deferens, seminal vesicles, prostate gland, urethra and penis.

• The female reproductive system in human beings consists of ovaries, fallopian tubes, uterus and vagina.

• Sexual reproduction in human beings involves the introduction of sperm in the vagina of the female. Fertilisation occurs in the fallopian tube.

• Contraception to avoid pregnancy can be achieved by the use of condoms, oral pills, copper-T and other methods.