NEET AIPMT Biology Chapter Wise Solutions – Reproduction in Organisms
1. Which of the following pairs is not correctly ma tched? (AlPMT 2015)
2. In ginger, vegetative propagation occurs through (AlPMT2015, Cancelled)
3. In oogamy, fertilization involves (2004)
(a) a small non-motile female gamete and a large motile male gamete
(b) a large non-motile female gamete and a small motile male gamete
(c) a large non-motile female gamete and a small non-motile male gamete
(d) a large motile female gamete and a small non- motile male gemete.
4. During regeneration, modification of an organ to other organ is known as (2001)
(d) accretionary growth.
5. The process of series of changes from larva to adult after embryonic development is called (1999)
6. ‘Nothing lives for ever, but life continues’. What does it mean? (1995)
(a) older die but new are produced due to reproduction
(b) nothing can produce without death
(c) death has nothing to do with the continuation of life
(d) parthenogenesis is must for sexual reproduction.
Sargassum is a brown alga. In brown algae, asexual reproduction occurs by means of spores and sexual reproduction varies from isogamy, anisogamy to oogamy.
The rhizome is a thickened, underground, dorsiventral stem that grows horizontally at a particular depth within the soil. It is brown in colour and shows cymose branching. It can be distinguished from the modified root by the presence of nodes, internodes, terminal buds, axillary buds and scale leaves. The rhizome are perennial and propagate vegetatively. They store food materials and appear tuberous. E.g., Zingiber officinale (ginger), Curcuma longa (turmeric), Canna indica.
Oogamy is the sexual reproduction involving the formation and subsequent fusion of a large, usually stationary, female gamete and a small motile male gamete. The female gamete may contain nourishment for the development of the embryo, which is often retained and protected by the parent organism.
There are two mechanisms of regeneration morphallaxis and epimorphosis.
(i) Morphallaxis. It involves the reconstruction of the whole body from a small fragment by reorganizing the existing cells. The regenerated organism is smaller than the original one, e.g., Amoeba. However, after the completion of the process it grows and attains normal size after some time.
(ii) Epimorphosis. It replaces a lost organ of the body by proliferating new cells from the surface of the wound or injured part. Regeneration of an appendage in an arthropod, arm in a starfish, and tail in a lizard occurs by the process of epimorphosis.
Metamorphosis is a process of series of changes of form from larva to adult after embryonic development. Regeneration is defined as replacement, repair or restoration of the lost or damaged structures or reconstitution of the whole body from a small fragment of it during the post-embryonic life of an organism. Growth is the result of greater anabolic (synthetic) processes over the catabolic (destructive) processes in the organism. Ageing may be defined as the progressive deterioration in the structure and functions of the cells, tissues and organs of an organism with the advancing age.
Death is a natural process by which the individuals die either naturally or due to illness, accident etc. But, before dying generally, individuals leave new individuals of their own kind through reproduction and thus the life continues.