Reproduction, Biology


  • It is not only production of new ones to increases its number but a means for the survival of a population on earth.
  • Main aim is "survival and continuation or race".
  • If there is no reproduction, species will become extinct just after one generation.
  • Reproduction is mainly of 2 types -

S .No.



Se x ua l


W ithout reproduc tive organs

Reprodutive organs present


No formation of gametes

Formation of gametes



Uni or biparental


Meiosis absent

Meiosis present


Offsprings are genetically similar to parents



No variation

Variation occur


Possibility of extinction is increased

Evolution occur

  • Animal may be unisexual or diocious (male & female are separate) and bisexual or monocious (male & female in same animal).
  • Unisexual are - insects, aschahelminthes & vertebrates.
  • Bisexuals are hydra, earthworm & platyhelminthes.
  • Fertilization may internal (inside body) e.g. sponges, platyhelminthes, aschahelminthes, arthropoda, reptiles, birds, mammals or external (outside body) e.g. coelenterata, earthworm, some pisces & amphibia.
  • Fertilization may be self (in same animal), e.g. tapeworm and crossed e.g. bisexual (protandrous e.g. hydra, earthworm, progynous e.g. sponges) & all unisexual animals.
  • Protandrous means testes mature first.
  • Progynous means ovary mature first.
Posted Date: 10/8/2012 5:44:11 AM | Location : United States

Related Discussions:- Reproduction, Assignment Help, Ask Question on Reproduction, Get Answer, Expert's Help, Reproduction Discussions

Write discussion on Reproduction
Your posts are moderated
Related Questions
Since the availability of flu vaccine is limited, who should receive any future pandemic flu vaccine?

Q. Define Premotor Cortex Located in the frontal lobes? Premotor Cortex - Involved in control of more complex, learned motor skills like writing, driving, etc. Broca's area or

Class of Crustacea - Copepoda Copepoda is a huge class of small (1-5mm) crustaceans occupying both marine and freshwater environments. Copepods form the several abundant and c

Syngamy The pollen tube grows to a very limited extent in the synergid. It releases the contents either through a terminal or a subterminal pore. The contents include the two

Oxygen Stratification - Lake Ecosystem In most lakes, oxygen stratification nearly parallels that of temperature during the summer season. The amount of oxygen is greatest on

The dynamic response of the building to earthquake ground motion is the most important cause of damages to the building that are induced by earthquake. Failure of the ground and so

Q. What is hematosis? In humans where does hematosis occur? Hematosis is the oxygenation of the blood, venous blood (oxygen-poor) after hematosis is transformed into arterial b

The presence of advanced plaques of types IV and Va allows clinical symptoms to develop. Atherosclerosis is a biphasic disease; in the first stage, advanced plaques are generated b

Rothera's Test It is highly sensitive for both acetoacetic and acetone. Although it is one of the oldest methods still it is widely used. Procedure: - Take about 5ml of