Asexual reproduction
Definition:
Asexual reproduction is a type of reproduction in which a single parent produces offspring without the fusion of gametes. The offspring are genetically identical to the parent and to one another (except for rare mutations). These genetically identical offspring are called clones.
Advantages
Only one parent is needed.
An organism can reproduce without finding a mate, allowing reproduction even when it is isolated or when few members of its species are nearby.
Reproduction is rapid.
Because no gametes or fertilization are involved, offspring can be produced quickly, allowing populations to increase rapidly.
Less energy is required.
Energy is not spent producing gametes, finding a mate, or carrying out courtship, leaving more energy for growth, survival, and reproduction.
Successful in stable environments.
If the parent is well adapted to its environment, its genetically identical offspring are also likely to survive and reproduce successfully as long as conditions remain unchanged.
Rapid colonisation.
A single organism can quickly produce many offspring and establish a large population in a suitable habitat.
Disadvantages
Little genetic variation.
The offspring are genetically identical, so there is very little variation within the population. This reduces the likelihood that some individuals will survive new diseases or environmental changes.
Greater risk from diseases and environmental changes.
Because the organisms are genetically similar, a disease or sudden environmental change may affect most or all of the population.
Harmful mutations can be inherited.
If the parent has a harmful mutation, it can be passed on to its offspring and spread through the population.
Cloning:
Definition:
Cloning is the process of producing one or more genetically identical copies (clones) of a cell or an organism. Clones have the same DNA as the original cell or organism (except for rare mutations) and therefore usually have the same inherited characteristics.
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Natural Cloning:
Natural cloning occurs without human involvement.
Examples include:
• Binary fission in bacteria.
• Budding in yeast.
• Spore formation in fungi.
• Vegetative propagation in plants.
• Fragmentation in some algae, fungi, and simple animals.
In each of these methods, the offspring are genetically identical to the parent because they are produced without fertilization.
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Artificial Cloning:
Artificial cloning is carried out by humans to produce organisms that are genetically identical to another organism.
The best-known method is somatic cell nuclear transfer (SCNT).
How SCNT Works:
1. The nucleus is removed from an egg cell.
2. The nucleus from a body (somatic) cell of the organism to be cloned is inserted into the empty egg cell.
3. The egg cell is stimulated to divide and develop into an embryo.
4. The embryo is implanted into the uterus of a surrogate mother, where it develops into a new organism.
The cloned organism has the same DNA as the organism that donated the nucleus and is therefore genetically identical to it (except for rare mutations).
Good.