Reproduction in Organisms - Class 12 Biology CBSE Notes

Life Cycle and Reproduction

• The period between birth and natural death of an organism is called the life cycle.
• The biological process of continuity of a race in which the grown-up individuals give rise to offspring similar to them is called reproduction.

Types of Reproduction

• Asexual reproduction involves a single parent capable of producing offspring that are genetically and morphologically identical to the parent.
• Binary fission is a type of asexual reproduction that involves the division of the parent body into many daughter organisms.
• In transverse binary fission, division occurs along the transverse axis of the individual.

Asexual Reproduction Methods

• Vegetative propagation is a type of asexual reproduction that involves the formation of a new plant from vegetative parts like root, stem, leaf, etc.
• Budding is a type of asexual reproduction in which a new organism grows from a small outgrowth on the parent organism, and the complex budded condition is called a zooid.
• Sporulation is a type of asexual reproduction that occurs by tiny, single-celled, thin-walled spores that form new individuals.

Exceptions and Repair

• The only exception to the statement that no individual organism is immortal is the Turritopsis dohrnii, also known as the "immortal jellyfish", which can transform its body into a younger state through a process called transdifferentiation.
• Regeneration is the process in which the missing part of the organism is repaired by the proliferation of cells.