Test: Biodiversity & Conservation - 1 - NEET MCQ

Urbanization means the increasing number of people that live in urban areas due to shifting from rural areas to urban areas. It affects the population density and leads to more loss of flora and fauna since more space for residence is occupied by humans.

The on-site or the protection and conservation of species (genetic resources) in their natural habitat (populations of plant or animal species) is called in-situ conservation. Areas such as biosphere reserves, national parks, and wildlife sanctuaries are the places were in-situ conservation is done.

The off-site or the protection and conservation of species (genetic resources) outside their natural habitat (populations of plant or animal species) is known as ex-situ conservation. Areas such as botanical gardens, zoos, Gene banks, Tissue culture banks are the places were ex-situ conservation is done.

If all members fo a host species die the parasite that obtain their food from the particular host also die off due to lack of food. This represent co-existence of species.

When we will move away from the equator towards poles there is a gradual decrease in the species diversity. This is because climatic condition becomes gradually adverse as we move from equator to poles.

Wetlands are areas where water is the primary factor controlling the environment and the associated plant and animal life. They occur where the water table is at or near the surface of the land, or where the land is covered by water.

India has about 50,000 type of rice and 1000 types of varieties of mango. This thigh level of diversity indicates very high genetic diversity and one of the largest in the world.

Species area relationship is the relationship between the area and the particular habitat. It is dependent on immigration, extinction and clustering etc. It was first studied by Alexander Von Humbolt.

International Union for Conservation of Nature (IUCN) was founded on 5 October 1948 in France by Julian Huxley. It is working in the field of conservation of nature and sustainable use of natural resources.

Those species whose number of individuals is greatly reduced to a critical level and are at a high risk of extinction in the wild are known as endangered species. Some examples of endangered species are Brown spider monkey, Bengal tiger, Ganga river dolphin, Indian Rhino, Black buck, etc.

A total of 34 hotspots in the world has been identified till date by Norman Myers.

When a graph is drawn to compare the relationship between species richness and area for wide variety of texa, the graph appears to be a rectangular hyperbola.

• The species of plants contribute to the traditional medicines used by native peoples around the world are approximately 25,000.
• Some examples of traditional plants used for medicinal purposes are ginger, garlic, chamomile, tulsi, etc.

The extent to which numbers of different species are equal or skewed well refer to species eveness or relative abundance. Species eveness or relative abundance depends upon availability of natural resources essential for organisms.

Cryopreservation is the method of preserving living organisms or their parts at extremely low temperature. To preserve seeds that rapidly lose viability and cannot survive desiccation are preserved by this method.

The impacts of introducing a non-native or invasive species to an ecosystem will vary depending on a number of factors.

In some instances, the introduced species may not survive. If there is no ecological niche for the species to fill or the species cannot adapt to fill a different ecological niche, the species will likely go extinct relatively quickly at the local level.

However, if the species is a generalist, or a species able to thrive in a variety of environments and consume many food sources, that species will likely do well. If the ecosystem has reached its stable state, this means that the invasive species will have to replace a native species. No two species can share the same ecological niche, thus one will be better adapted and survive. If the invasive species is better adapted, it will out compete the native species.

If the species reproduces quickly, it is also more likely to thrive in a new ecosystem. If it can reproduce and grow faster than its competitor, it will eventually out compete that species.

Typically, invasive species harm an ecosystem. For example, the Burmese python is found in the US but it isn't supposed to be here. These snakes were likely released by humans and were pets at one time. The environment is suitable for them and they have adapted to the area.

Introducing a new species can also introduce any diseases that species has. These new diseases can spread to other native species and negatively affect them.

Introducing exotic species into new areas will increase competition for food and space. Sometimes, exotic species brings disease along with them. Exotic species in new area do not lead to extinction of native species.

More than 15,500 species worldwide is facing threat of extinction which includes amphibians, gymnosperms, reptiles, birds and mammals etc.

• The Amazon rainforest is the world’s largest tropical rainforest and is also known as the Amazon Jungle or Amazonia.
• Approximately 20 percent of the total oxygen in the Earth’s atmosphere is released by the Amazon forest by the process of photosynthesis.

The organisms that has been completely eliminated or died out from earth are called extinct organisms. For example Dodo.

In general, loss of biodiversity in a region may lead to (a) decline in plant production, (b) lowered resistance to environmental perturbations such as drought and (c) increased variability in certain ecosystem processes such as plant productivity, water use, and pest and disease cycles.

Amzonian rain forests are called as lungs of forest because it contains different kinds of vegetation that purify the atmosphere of the earth.

• More than 70 per cent of all the species recorded are animals, while plants (including algae, fungi, bryophytes, gymnosperms and angiosperms) comprise no more than 22 per cent of the total.
• Among animals, insects are the most species rich taxonomic group, making up more than 70 per cent of the total.

• They identified for maximum protection certain ‘biodiversity hotspots’ regions with very high levels of species richness and high degree of endemism (that is, species confined to that region and not found anywhere else).
• These hotspots are also regions of accelerated habitat loss.

• India has also a history of religious and cultural traditions that emphasised protection of nature.
• In many cultures, tracts of forest were set aside, and all the trees and wildlife within were venerated and given total protection.
• Such sacred groves are found in Khasi and Jaintia Hills in Meghalaya, Aravalli Hills of Rajasthan, Western Ghat regions of Karnataka and Maharashtra and the Sarguja, Chanda and Bastar areas of Madhya Pradesh.