(a) Arrhenotoky: In this type, only males are produced by parthenogenesis. eg: honey bees
(b) Thelytoky: In this type of parthenogenesis only females are produced by parthenogenesis. e.g: Solenobia
(c) Amphitoky: In this type parthenogenetic egg may develop into individuals of any sex. e.g: Aphis.

(i) Buds are formed on the outer surface of the parent body, it is known as exogenous budding e.g. Hydra.
(ii) In Hydra when food is plenty, the ectoderm cells increase and form a small elevation on the body surface.
(iii) Ectoderm and endoderm are pushed out to form the bud. The bud contains an interior lumen in continuation with parent's gastrovascular cavity.
(iv) The bud enlarges, develops a mouth and a circle of tentacles at its free end.
(v) When fully grown, the bud constricts at the base and finally separates from the parent body and leads an independent life.

(i)  In Ovoviviparous animals, the embryo develops inside the egg and remains in the mother's body until they are ready to hatch.
(ii) This method of reproduction is similar to Viviparity but the embryos have no placental connection with the mother and receive their nourishment from the egg yolk. Ovoviviparity is seen in fishes like shark.

(i) It is a mode of asexual reproduction in sponges.
(ii) Internal buds called gemmules are formed which is a hard ball, consisting of an internal mass of food laden archaeocytes.
(iii) During unfavourable conditions, the sponge disintegrates, but the gemmule withstands adverse conditions.
(Iv) The gemmules hatch during favourable conditions.

(i) Reproduction by a single parent without the involvement of gamete formation is asexual reproduction and the offspring produced are genetically identical. (uniparental inheritance)
(ii) Asexual reproduction is usually by amitotic or mitotic division of the somatic (body) cells, hence is also known as somatogenic or blastogenic reproduction. Eg. members of Protista, Bacteria.