A type of reproduction by which offspring is produced from s single parent with or without...
Asexual reproduction
A type of reproduction by which offspring is produced from s single parent with or without the involvement of gamete formation. (uniparental).
Types of asexual reproduction
I. Fission:
A mode of asexual reproduction in which a parental cell splits up into two or more daughter cells.
Binary fission: A parental cell divides into two equal daughter cells and each rapidly grows into an adult.
Multiple fission: The splitting of a parental cell into numerous daughter cells, each of which grow into an adult. E.g., Plasmodium.
II. Fragmentation:
It is a mode of asexual reproduction in which the parental body breaks into two or more fragments and each fragment grows into a new individual, e.g., Spirogyra.
III. Budding:
It is a mode of asexual reproduction in which one or more outgrowths (buds) are produced which initially remain attached to the parent cell and eventually get separated from it to grow into a new individual, e.g., yeast, Hydra.
IV. Regeneration:
It is a mode of asexual reproduction in which the missing parts of an organism is repaired by proliferation of cells, e.g., Planaria.
V. Spore formation:
Zoospores: These are endogenously produced unicellular, naked and motile spores with one or two flagella. Zoospores are produced in a sac-like structure called zoosporangium, e.g., Chlamydomonas.
Conidia: Asexual non-motile spores cut off externally either singly (e.g., Phytophthora) or in chains (e.g., Penicillium) from the tip of a special hyphae called conidiophore.
Gemmules: Internal asexual reproductive units or buds are called gemmules, e.g., sponges. These develop within the parental body and are released during germination.
VI. Vegetative propagation:
It is a mode of reproduction in which new plants are formed from vegetative parts (vegetative propagules) of the plant like root, stem, etc. It is very common in higher angiosperms.
Following are some units of vegetative propagation:
Bulbil – Agave
Bulbs – Onion, Garlic
Eyes – Potato
Leaf buds – Bryophyllum
Offset – Hyacinth and Pistia
Rhizome – Ginger
Runner – Oxalis
Sucker – Mint