Discuss the advantages and disadvantages of asexual reproduction by making reference to different types of asexual reproduction in plants and animals(Refer to cloning, binary fission, formation, vegetative reproduction, parthenogenesis, budding and fragmentation).
To ensure the continuation of the species, plants and animals use two methods of reproduction - sexual and asexual. Sexual reproduction is the more common form of reproduction. It involves the fusing of two gametes, one from each partner to form a new being. Asexual reproduction doesn't require a second partner.
Vegetative reproduction is a form of asexual reproduction in plants, where parts of the plant fall off and develop into new plants. Potato tubers are one example of a plant that used this form of reproduction. Since asexual reproduction doesn't require another partner, or pollen transfer it is very quick and is guaranteed. This is very good for people using potatoes in their products, because reproduction is very fast, so they can make more potatoes, and hence make more money. The main disadvantage of this form of reproduction, is that the new plants will all grow very close to each other and to the parent. This will cause a struggle for soil, nutrients and light, and will consequently cause the plants to be less healthy.
Fragmentation is another form of asexual reproduction in plants, and is very similar to vegetative reproduction. This is when an organism is broken into 2 or more pieces, and each one grows into a new individual. For this type of reproduction the plant must have good powers of regeneration. This could be a disadvantage if the plant is in poor conditions, as it wouldn't have good powers of regeneration, and so it wouldn't be able to reproduce. On the positive side, it can produce many new individuals very quickly.
Hydra rely on a budding form of asexual reproduction, where it develops an outgrowth, which when detached from the parent, becomes a new individual. This is perfect for the Hydra, which doesn't move around much, so its chances of finding a partner are slim.
Spores are unicellular bodies, formed by the parent organism to carry out reproduction, and is very common in prokaryote and fungi. If environmental conditions are suitable, the spore will develop into a new individual. This is one of the disadvantages, as it will only occur during the correct conditions. Spores come in a wide variety of forms and are produced and dispersed in many different ways.
Spores are very effective, because they are small and light, and so can be carried by wind, water or animals; so they can travel far away from the parent, perhaps to better conditions. Some spores have thick walls which can give them protection against unfavourable conditions. Because the spores are so small, the organism can afford to release more of them, so there will be more spores surviving.
Each method of reproduction has its own set of advantages and disadvantages. Overall asexual is faster and easier than sexual reproduction, because another partner is not needed, and doesn't have to be found. Another advantage of asexual reproduction, is that the animal or pollen grains doesn't have to travel in order to propagate the species, which means it can conserve energy and be more discreet. Because genetic information is shared by the two gametes in sexual reproduction, variety is produced in the species. if one agrees with the theory of evolution, then this factor is a very good one, as variety ensures the death of species with a certain weak element, and the survival of species with an advantageous element. This will create a better species, who is better at surviving. On the other hand, asexual reproduction doesn't allow any type of genetic variation, this is an advantage, because any mutations or "bad" qualities will be passed on, and cannot leave the life chain of that species. Asexual reproduction is more reliable than sexual, because there are less steps to follow and therefore less can go wrong, for instance pollen transfer is very flimsy and since asexual reproduction doesn't need this, it is more reliable.