Answer:
a) Indicator species are like the messenger. These species provide warning of damage for a community or ecosystem, for example birds. Amphibian species like frogs, toads are the major adapters of the environmental conditions. These by reacting to the changing environment conditions informs to the ecosystem.
b) Key stone species are those species which are having a very large effect on the other species of the ecosystem. These species are present in limited number in the ecosystem but these species have very large effect. These species helps in maintaining the balance in ecosystem.
Answer:
Human species are not key stone species because these species are present in very large number and thus have a very large effect on the ecosystem. If the humans are on the verge to extinct then species which are dependent on the humans were also become extinct. Most of the pets like dogs, cats and pigs live with the humans and is dependent on the food provided by the humans. Birds are also dependent on the agriculture fields. The species which were grow are fish, insects, and tropical forest animals.
Answer:
The key concept of this section states that if there is change in the environmental condition then balance between the new species and extinction of other species determines the earth biodiversity. The second key concept of this section is about the human activities. Human activities are affecting the biodiversity. The process in which one species split in to two are more species is called as speciation. When the organisms of the same species or population of the species is not in physical touch for a very long time then it is called as geographic isolation. The earth tectonic movement causes some of the geographic isolation. In the graphically isolated populations the change in the gene pool and mutation in the gene pool is called as reproductive isolation. Reproduction process led to many different and new species and genetic variation exist in the population.
In artificial selection the breeding is done according to choice. For example a species such as fruit, dog is selected and crossbreed with the other species in such a way that to bring the fruitful results and variation in the population. Genetic engineering is branch of science which deals with the manipulation of genes. In this genes are manipulated according to the need of desired traits. For example cold water fish can be used enhance the tomato plant so that it can develop resistance to cold.