Asexual reproduction

Asexual Reproduction

= formation of new individuals from the cells of a single parent. Offspring are identical to their parent. Does not involve meiosis.

Advantages

-         Allows an organism to rapidly produce many offspring, saving time and energy for courtship,finding a mate,and mating.

-         Combination of genes to be handed down unchanged.

Disadvantages

-         Reduces genetic variation, disadvantage in the long term for the evolution and adaption of a species to its changing environment.

-         Harmful mutation sometimes pass on to progeny.

(1)  Binary fission

(2) Fragmentation

- parts of plant break off and grow into new plant.

(3) Sporulation

- formation of spores

- haploid

(4) Budding

- a small protuberance on the surface of parent cell increases in size until a wall forms to separate the new individual or bud from the parent.

(5) Regeneration

- ability of body to replace lost parts of an organism

(6) Vegetative reproduction

- that describes all the natural methods of asexual reproduction used by plants.

(7) Parthenogenesis

- an individual develops from an unfertilized egg.

- in most species, reproduction by parthenogenesis occurs when conditions are right and food is plentiful, at other times, sexual reproduction takes place.

(8) Polyembryony

- ability of fertilised egg to develop into mass of cells that will then form numerous embryos.

- e.g.: identical twins

(9) Paedogenesis

- reproduction by an animal that still in larvae form or pre-adult

- e.g.:Lancelet (amphioxus)