Biology

Biodiversity and Conservation

Question:

Give three hypothesis for explaining why tropics '”show greatest levels of species richness.

Answer:

(1) The tropical area have a more stable climate than temperate zones. Local species continues to live in absence of natural disturbances.
(2)Warm temperature and high humidity in most tropical areas provide favourable conditions for growth and survival of diverse species.
(3)Tropical areas receive more solar energy over year and thus tropical communities are more productive and can support a wide range of species.

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Biodiversity and Conservation

Q 1.

What could have triggered mass extinctions of species in the past?

Q 2.

The species diversity of plants (22 per cent) is much less than that of animals (72 per cent).What could be the explanations to how animals achieved greater diversification?

Q 3.

What are the major causes of species losses in a geographical region ?

Q 4.

Define gene pool.

Q 5.

What are sacred groves? What is their role in conservation?

Q 6.

What is an endangered species? Give an example of an endangered plant and animal species each.

Q 7.

How can you, as an individual, prevent the loss of biodiversity?

Q 8.

What does Red' indicate in the IUCN Red list (2004)?

Q 9.

Why is genetic variation important in the plant Rauwolfia vomitorial ?

Q 10.

List any two major causes other than anthropogenic causes of the loss of biodiversity.

Q 11.

How is the presently occurring species extinction different from the earlier mass extinctions?

Q 12.

Elaborate how invasion by an alien species reduces the species diversity of an area.

Q 13.

Name the three important components of  biodiversity.

Q 14.

How do scientists extrapolate the total number of species on Earth?

Q 15.

Is it true that there is more solar energy available in the tropics? Explain briefly.

Q 16.

Of the four major causes for the loss of biodiversity (Alien species invasion, habitat loss and fragmentation, over-exploitation and co-extinctions which according to you is the major cause for the loss of biodiversity? Give reasons in support.

Q 17.

According to David Tilman, greater the diversity, greater is the primary productivity. Can you think of a very low diversity man-made ecosystem that has high productivity?

Q 18.

What criteria should one use in categorizing a species as threatened?

Q 19.

What is Red Data Book?

Q 20.

Why are the conventional methods not suitable for the assessment of biodiversity of bacteria?

Q 21.

What is co-extinction? Explain with a suitable example.

Q 22.

Humans benefit from diversity of life. Give two examples.

Q 23.

Is it possible that productivity and diversity of a natural community remain constant over a time period of, say one hundred years?

Q 24.

Suggest a place where one can go to study coral reefs, mangrove vegetation and estuaries.

Q 25.

What is common to the species shown in figures A and B?
ncert-exemplar-problems-class-12-biology-biodiversity-conservation-6

Q 26.

What is an ecosystem service? List any four important ecosystem services provided by the natural ecosystems. Are you in favour or against levying a charge on the service provided by the ecosystem?

Q 27.

What are sacred groves and their role in biodiversity conservation?

Q 28.

Give three hypothesis for explaining why tropics '”show greatest levels of species richness.

Q 29.

What characteristics make a community stable?

Q 30.

What is common to the species shown in figures A and B?
ncert-exemplar-problems-class-12-biology-biodiversity-conservation-7

Q 31.

Can you think of a situation where we deliberately want to make a species extinct? How would you justify it?

Q 32.

How do ecologists estimate the total number of species present in the world?

Q 33.

What does the term Frugivorous' mean?

Q 34.

Though the conflict between humans and wildlife started with the evolution of man, the intensity of conflict has increased due to the activities of modem man. Justify your answer with suitable examples.

Q 35.

What is the significance of the slope of regression in a species – area relationship?

Q 36.

Match the animals given in column A with their location in column B.
ncert-exemplar-problems-class-12-biology-biodiversity-conservation-1
Choose the correct match from the following:
(a) i  ”A, ii ”C, iii B, iv D (b) i ”D, ii”C, iii ”A, iv”B
(c) i”C, ii”A, iii”B, iv”D (d) iâC, iiA, iii”D, iv”B

Q 37.

How is biodiversity important for ecosystem functioning?

Q 38.

Can you think of a scientific explanation, besides analogy used by Paul Ehrlich, for the direct relationship between diversity and stability of an ecosystem?

Q 39.

How does species diversity differ from ecological diversity?

Q 40.

What is the difference between endemic and exotic species?

Q 41.

Describe the consumptive use value of biodiversity as food, drugs and medicines, fuel and fiber with suitable examples.

Q 42.

The relation between species richness and area for a wide variety of taxa turns out to be a rectangular hyperbola. Give a brief explanation.

Q 43.

There is greater biodiversity in tropical /subtropical regions than in temperate region. Explain.

Q 44.

he one-homed rhinoceros is specific to which of the following sanctuary
(a) Bhitar Kanika (b) Bandipur (c) Kaziranga (d) Corbett park

Q 45.

A species-area curve is drawn by plotting the number of species against the area. How is it that when a very large area is considered the slope is steeper than that for smaller areas?

Q 46.

Discuss one example, based on your day-to-day observations, showing how loss of one species may lead to the extinction of another.

Q 47.

Explain as to how protection of biodiversity hot spots alone can reduce up to 30% of the current rate of species extinction.  

Q 48.

Explain briefly the ˜rivet popper hypothesis' of Paul Ehrlich.

Q 49.

What accounts for the greater ecological diversity of India?

Q 50.

Species diversity decreases as we move away from the equator towards the poles. What could be the possible reasons?