REPRODUCTION IN ORGANISMS

Reproduction in organisms is defined as a biological process in which an organism gives rise to young ones like itself. The offspring grow, mature and in turn produce new offspring. Thus, there is a cycle of birth, growth, and death. There is a large diversity in the biological world and each organism has evolved its own mechanism to multiply and produce offspring.

Here there are some factors that are collectively responsible for how the organism reproduces such as the organism’s habitat, its internal physiology and several other factors. Based on whether there is participation of one organism or two in the process of reproduction, it is of two types

  1. Asexual
  2. Sexual

Asexual Reproduction in organisms:

In this method, a single individual (parent) can produce offspring. And in this process the offspring that are produced are not only identical to one another but are also exact copies of their parent. The term clone is used to describe such morphologically and genetically similar individuals.

It is common among the single celled organisms and among the plants and animals with simple organisations.

Example: yeast, fungi, bacteria

Sexual reproduction in organisms:

This involves the formation of male and female gametes either by single individual or by different individuals of opposite sex. These gametes fuse to form the zygote which develops to form a new organism. It is complex and slow process as compared to asexual reproduction. And in sexual reproduction the offspring are not identical to the parents or amongst themselves.

Sexual reproduction is a complex process which includes various events such as
  1. Pre fertilization events
  2. Fertilization
  3. Post fertilization events
Example : Humans

Reproduction in Organisms - List of Topics

Asexual reproduction Budding (yeast)
Binary fusion(amoeba)
Encystation and sporulation (Amoeba) with diagrammatic explanation
Zoospore (Chlamydomonas)
Conidia (penicillium)
Buds (hydra)
Gemmules (sponges)
Fragmentation9(hydra)
Vegetative propagation
Definition and mentioning the vegetative propagules like runner
Sucker Rhizome (ginger and banana)
Tuber (potato)
Offset (water hyacinth) Bulbil(agave) Leaf buds (Bryophyllum)
Sexual reproduction Definition
Phases of life cycle
a.      Juvenile
b.      Reproductive and
c.      Senescence phases
Events in sexual reproduction
1. Pre- fertilization Events
a.      Gametogenesis
b.      Gamete Transfer
2. Fertilization
a.      External fertilization
b.      Internal fertilization: parthenogenesis
3. Post-fertilization events
a.      The Zygote
b.      Embryogenesis
c.      Oviparous and Viviparous animals