Asexual Reproduction in Organisms – NEET Biology Class 12
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Asexual Reproduction in Organisms – NEET Biology Class 12

Welcome to NEETLab. This is a 100% free online self learning platform
to improve your intelligence and to clear NEET examination. In this video we are going to understand the
asexual reproduction. In asexual reproduction method, a single individual
is capable of producing offspring. As a result, the offspring that are produced
are not only identical to one another but are also exact copies of their parent. Naturally the question will rise whether these
offspring are genetically identical to the parent or different? The term clone is answer for this question. What is clone. A plant or animal that has the same genes
as the original from which it was produced. It means youngones are genetically identical
to its parent. Now, Let us see different kinds of asexual
reproduction in different groups of organisms. As we know asexual reproduction is common
among single-celled organisms like amoeba, bacteria, and asexual reproduction is seen
in plants and animals with relatively simple organisations for example in Protists and
Monerans, the organism or the parent cell divides into two to give rise to new individuals
. Thus, in these organisms cell division is itself a mode of reproduction. As we know, in Many single-celled organisms
reproduce by binary fission, where a cell divides into two halves and each rapidly grows
into an adult. For example reproduction process in amoeba
and Paramecium. But in yeast, the division is unequal and
small buds are produced that remain attached initially to the parent cell which, eventually
gets separated and mature into new yeast organisms. In Fungi and simple plants such as algae reproduce
through special asexual reproductive structures. Look at this picture. These are the different reproductive structures
by which organism reproduce. Zoospores of chlamydomonas; (b) Conidia of
Penicillium; (c) Buds in Hydra; (d) Gemmules in sponge are the most common of these structures. In plants, the units of vegetative propagation
such as runner, rhizome, sucker, tuber, offset, bulb are all capable of giving rise to new
offspring . These structures are called vegetative propagules. Please note vegetative propagule is a vegetative
structure that can become detached from a plant and give rise to a new plant. Obviously, since the formation of these structures
does not involve two parents, the process involved is asexual. Are you aware how plants like potato, ginger
and other such plants are cultivated? Look at this picture small plants emerging
from the buds (called eyes) of the potato tuber it is called eyes of potato and from
the rhizomes of ginger, from the bulbil of agave, from the leaf buds of Bryophyllum and
from offset of water hyacinth . If you carefully try to determine the site of origin of the
new plantlets in the plants listed above, you will notice that they invariably arise
from the nodes present in the modified stems of these plants. When the nodes come in contact with soil or
water, they produce roots and new plants. Similarly, adventitious buds arise from the
notches present at margins of leaves of Bryophyllum. This ability is fully exploited by gardeners
and farmers for commercial propagation of such plants. It is interesting to note that asexual reproduction
is the common method of reproduction in organisms that have a relatively simple organisation,
like algae and fungi and that they shift to sexual method of reproduction just before
the onset of adverse conditions. Find out how sexual reproduction enables these
organisms to survive during unfavourable conditions? Why is sexual reproduction favoured under
such conditions? Asexual (vegetative) as well as sexual modes
of reproduction are exhibited by the higher plants. On the other hand, only sexual mode of reproduction
is present in most of the animals. Lets discuss the sexual reproduction in organisms
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