Question.2. Answer the following questions in about 30 words.

(i) What is biodiversity?
Answer. The word “biodiversity” is a compound of the words “bio” (for life) and “diversity” (variety). The quantity and variety of species that may be discovered within a certain geographic area are known as biodiversity. It refers to the different species of plants, animals, and microorganisms and the genes and ecosystems each contains. It has to do with the variation among earth’s living things, including within and between species and between ecosystems.

(ii) What are the different levels of biodiversity?
Answer. Biodiversity can be discussed at three levels:
(a) Genetic diversity
(b) Species diversity
(c) Ecosystem diversity

1. Genetic diversity: Genetic diversity refers to the variation of genes within species.
2. Species diversity: Species diversity refers to the variety of species. It relates to the number of species in a defined area. The diversity of species can be measured through their richness, abundance and types.
3. Ecosystem diversity: The broad differences between ecosystem types and the diversity of habitats and ecological processes occurring with in each ecosystem type constitute ecosystem diversity.

(iii) What do you understand by ‘hotspots’?
Answer. There are some regions with more species than others. Hotspots of diversity are places with high levels of species variety. Hotspots are classified based on the vegetation they contain. Because they control an ecosystem’s primary production, plants are significant. Most of the hotspots, but not all of them, depend on ecosystems with a variety of species for their food, fuel, agriculture, and timber income.

(iv) Discuss briefly the importance of animals to human kind.
Answer. Species capture and store energy, produce and decompose organic materials, help to cycle water and nutrients throughout the ecosystem, fix atmospheric gases and help regulate the climate. These functions are important for ecosystem function and human survival.

(v) What do you understand by ‘exotic species’?
Answer. Exotic species are those that have been introduced into a system but are not native inhabitants of the area. There are several instances where the introduction of alien species caused significant harm to an ecosystem’s indigenous biotic community.

Question.3. Answer the following questions in about 150 words.

(i) What are the roles played by biodiversity in the shaping of nature?
Answer. In an ecosystem, several species provide a variety of purposes. Nothing changes or persists in an ecosystem without a cause. It suggests that each creature provides something valuable to other species in addition to meeting its own requirements. The maintenance of ecosystems is greatly aided by human activity.

1. Species contribute to the cycle of water and nutrients through the ecosystem, fix atmospheric gases, control climate, generate and degrade organic materials, and collect and store energy. These processes are necessary for both human existence and ecological health.
2. The likelihood that a species will survive challenges and predators is higher in a more diversified habitat, which is more productive.
3. Hence, the loss of species would decrease the ability of the system to maintain itself. Like a species with high genetic diversity, an ecosystem with high biodiversity may have a greater chance of adapting to environmental change.

(ii) What are the major factors that are responsible for the loss of biodiversity? What steps are needed to prevent them?
Answer. The pace of natural resource use has grown during the previous several decades due to populatio n expansion. It has hastened the extinction of animals and the loss of human settlement in several places on the earth.

1. To meet the requirements of a huge population, overuse of resources and deforestation have become widespread. The loss of natural ecosystems has severely affected the biosphere since these tropical rainforests are host to 50% of the world’s species.
2. Flora and fauna of the planet are harmed by natural disasters like earthquakes, floods, volcanic eruptions, forest fires, droughts, etc., which alter the biodiversity of the afflicted regions.
3. Pesticides and other contaminants like hydrocarbons and harmful heavy metals wipe out the weak and vulnerable species.

Conservation strategy has suggested the following steps for biodiversity conservation:

1. Efforts should be made to preserve the species that are endangered.
2. Prevention of extinction requires proper planning and management.
3. Varieties of food crops, forage plants, timber trees, livestock, animals and their wild relatives should be preserved.
4. Each country should identify habitats of wild relatives and ensure their protection.
5. Habitats where species feed, breed, rest and nurse their young ones should be safeguarded and protected.
6. International trade in wild plants and animals should be regulated.