Asexual reproduction is a process in which new organism is produced from a single parent without the involvement of gametes or cells. Many unicellular and multi cellular organisms reproduce asexually.
2. Asexual Reproduction in Plants
1. Involves only one parent,
2. Does not involve seeds or the fusion of gametes
3. Instead part of a plant’s stem, leaves or roots can become new
plants,
4. Produces offspring / clones genetically identical to the parent,
5. Allows plants to be produced much faster then sexual
reproduction.
There are six types of a sexual reproduction. They are:
1) fission
2) budding
3) spore formation
4) regeneration
5) fragmentation
6) vegetative propagation
4. There are two types Fission : In fission, unicellular organism splits to form new
organisms. It is a process of reproduction in organisms such as protozoa and many
bacteria.
Binary Fission:
In binary fission, the parent cell divides into two after reaching a point where it
has fully grown. In this process, after splitting parent cell do not exist and two new
organisms are formed. Examples of unicellular organisms that undergo binary
fission are amoeba, paramecium, Leishmania etc.
5. Multiple Fission:
Multiple fission is also a process of asexual reproduction in which parent cell
splits to form many new organisms. This happens when cyst is formed around a
unicellular organism. Inside this cyst the nucleus of an organism breaks in many
smaller nuclei. When the favorable conditions come, the cyst breaks and the
many daughter cells inside it are released. Plasmodium
6. Budding:
The word bud means small outgrowth. In the process of budding, a small
bud grows on the body of parent organism and when the time comes it
detaches itself to form a new organism. Hydra and yeast undergoes the
process of budding.
Hydra reproducing by the method of budding.
Yeast reproducing by the method of budding.
7. •Spore formation
The method of spore formation occurs in both unicellular and multi-cellular
organisms. This process takes place in plants. In spore formation, the parent plant
produces hundreds of reproductive units called spores in its spore case. When
this spore case of the plant bursts, these spores travel in air and land on food or
soil. Here they germinate and produce new plants.
EX: Fungi like Rhizopus, Mucor, etc., are examples of spore formation.
8. Regeneration
Regeneration is an asexual method of reproduction. In this process, if the body of
a parent organism gets cut, then each cut part can regenerate and form a whole
new organism from its body parts. This happens because when the body of an
organism that can undergo regeneration gets cut then the cells of cut body part
divide rapidly and form a ball of cells. These cells then move to their proper places
to form organs and body parts. Regeneration occurs in both plants and animals.
EX: Hydra and planaria undergo regeneration.
Regeneration in Planeria.
9. •Fragmentation
Fragmentation occurs in multicellular organisms, be it plants or animals. In this
process the multicellular organism breaks into two or more pieces on maturation.
Each piece than grows into a new organism. Spirogyra which is a plant and sea
anemones which is a sea animal undergoes the process of fragmentation.
10. Vegetative Propagation:
Vegetative propagation is a type of sexual reproduction in which the 1. Stems
(Runner, tuber, rhizome and &bulb) 2. Roots, 3.Leaves 4.Buds give rises in to
new plant. These are also called vegetative parts of the plants.
11. 1. Modified Stems
(a) Runners
• Horizontal stem which grows or runs over the soil surface.
• The terminal bud sends up new shoots & down new roots from it.
Ex: Strawberries
14. D. Bulbs:
Stem covered with modified leaves which can produce a new plant.
Ex: Onion
E. Food Storing Roots
Roots which are capable of producing a new plant
Ex: carrots & beets
15. 3. Modified Leaves
• Some plants produce Plantlets along the edges of the leaves.
• When they reach a certain size, they fall off and grow into new plants.
Ex: Cacti
16. 4. Modified Buds
Bulbs :
A bulb (an underground bud) has a reduced stem, roots, fleshy leaves swollen
with stored food and a main bud in the centre which grows into a new plant
Ex: Onion, Daffodil, Tulip
17. Vegetative Propagation
Artificial Method of Asexual reproduction most used in agriculture
1. Cuttings- pieces of stem cut from parent kept in water, moist soil or sand
Will put out new roots.
Ex:-Many garden plants like
18. Grafting- Buds or sections are cut from one plant is attached to another that is
already rooted in the soil.
Ex- Roses, Fruit Trees
19. 3. Layering : A branch of a plant is bent over and pinned down into the soil at a
node. It is covered over with soil & eventually new roots & shoots
develop useful for the propagation of woody plants.
Ex: blackberry, gooseberry.
20. 4.Tissue culture-
pieces of the center of stem are removed placed in flasks with growth
medium a whole new plant will develop
21. Advantages of artificial vegetative propagation
•The new plant will have exact features as that of parent plant.
•Fruit trees grown by grafting bear fruit much earlier.
•Plants need less attention in their early years.
•Many plants can be grown from just one parent.
•Can get seedless plants.
Thank you,
Nanditha Akunuri
B.Sc, B.Ed, M.sc, M.A, M.Ed, (P.hD)
Hinweis der Redaktion
2. Rhizomes-
modified stems that grow under the soil, produce new roots from stem.
Ex- Grasses
3. Tubers-
shorter, thicker stems that produce an “eye” which is capable of producing a new plant.
Ex-Potato