Biodiversity and Conservation

Previous Years' CBSE Board Questions

13.1 Biodiversity

MCQ

1 The IUCN Red Data List (2004) in the last 500 years documents the extinction of nearly 784 species including

1. 330 invertebrates
2. 338 invertebrates
3. 359 invertebrates
4. 362 invertebrates. (2023) R

June 22 Dec. 22 June 22

Dec. 22

Solarradiation Solarradiation radiation Solar radiation Solar

1. hr. 12 24 hr. 1. hr. 12 24 hr. 1.hr. 12 24 hr. 1.hr. 12 24 hr.

Time of the day Time of the day Time of the day Time of the day (X) 2 Human settlement often leads to habitat loss which leads to fragmentation, forming smaller patches of habitats. Select the statements that describe how a small patch differs from a large patch of the same habitat. Invasive species will never be seen here.

1. Population of large animals decreases.
2. Biodiversity decreases.
3. Competition from surrounding habitats increases.
4. (ii), (iii) and (iv) only
5. (ii) and (iv) only
6. (i) and (iii) only
7. (i), (ii) and (iii) only (2023) R

1. It is observed that the species diversity decreases as we
2. move away from equator to poles
3. move towards equator from poles
4. move along the equator
5. move from deserts to rainforests. (2020) R

<math>S = CA^2</math>

1. Species-area relationship is represented on a log scale as
2. hyperbola
3. rectangular hyperbola
4. linear
5. inverted.

Species richness log-log-scale <math>log S = log C + Z log A</math>

VSA. (1 mark)

Area ---

1. Identify'a' and 'b' in the figure given below representing proportionate number of major vertebrate taxa.

SA I (2 marks)

The graphs (X) and (Y) below depict the diurnal

variations in the solar radiations in the month of

June (Summer) and in December (Winters):

Which of the two graphs depicts tropical region

and temperate regions respectively?

Which of the two region (X) or (Y) will show high

biological diversity and why?

(Term II, 2021-22) [An

Substantiate with the help of one example that in an

ecosystem mutualists (i) tend to co-evolve and (ii)

are also one of the major causes of biodiversity loss.

(Delhi 2019)

List four causes of biodiversity loss. (Delhi 2014C)

SA II (3 marks)

1. Explain the concept of "co-extinction" by taking two examples. (Term II, 2021-22)
2. (a) Write the inference drawn by Alexander von Humboldt after his extensive explorations of South American jungle.
3. Study the graph given below:

As per Alexander von Humboldt, what do the symbols

S, A, Z and C in the graph stand for, in respect of a

species and area relationship?

Vertebrates а

(Term II, 2021-22)

Fishes Birds etting filler 11. How have the following factors affected the

biodiversity of an area?

Reptiles Explain.

1. Habitat loss and fragmentation
2. Over-exploitation (Term II, 2021-22 C)

(Delhi 2014)

1. The graph given below shows species-area relationship of a certain region.

500 Vertebrates

% 400-<br>$ 300-<br>$ 200- Х Mammals 100 0 0 10 20 30 40 50 60. Area evaluated (in hectares)

1. Study the graph and explain what it represents.
2. After a while, a small area was taken for constructing a road which divided the region into two. Write the impact this construction would have on species richness of the region.

(Term II, 2021-22) (Ap)

How did Dr. David Tilman relate experimentally, the stability of a community and its species richness? Explain. (Term II, 2021-22) U

1. Study the pie chart given below, representing the global diversity: proportionate number of species of

major taxa and answer the following questions based on it.

<math>S = CA^{\mu}</math>

Invertebrates Other animal groups 17/1 Species richness Crustaceans 108-1085Cale log S = log C + Z log A 'X' Area →

1. Identify 'X' and 'Y' in the given pie chart.
2. Whichone of the two, 'X' or 'Y', is the most species- rich taxonomic group and by what percentage? (Term II, 2021-22 C)

What are the consequences of loss of biodiversity in a region? Explain. (Term II, 2021-22) R

Given below is an equation describing the Species-Area relationship between species richness and area for a wide variety of taxa as angiosperm plants, birds, bats etc.

<math>S = CA^{Z}</math>

1. Give a graphical representation of the given equation showing Species-Area relationship.
2. What does 'S' represent in the given equation?
3. What is the value of 'Z' (regression coefficient) for frugivorous birds and mammals in the tropical forests of different continents? (Term II. 2021-22)
4. Given below is a 'pie chart' representing the global biodiversity: proportionate number of species of major taxa.

Identify (X) and (Y) in the given 'pie chart'.

1. "Extinction of species across taxa are not random." Which group amongst the vertebrates is more vulnerable to extinction?
2. Give one example each of recent extinctions of species in Russia, Mauritius and Australia.

(Term II, 2021-22)

1. Study the graphical representation of Species richness-Area relationship given below and answer the questions that follow:
2. What do S, C, Zand A represent in the given graph?
3. What will be the range value of 'Z line' if we analyse the species-area relationship among very large areas like entire continent? (2021 C)

Alien species invasion has been a threat to biodiversity.

Justify with the help of a suitable example. List any

other three causes responsible for such a loss. (2020)

Tigers inhabit forests. Over the past many decades

the tiger population was on the decline in our

country. A project 'Save Tiger' was launched in 1973

to conserve this precious species. It is heartening

to see in the last couple of decades that there has

been a gradual increase in the tiger population in our

country.

Answer the questions:

1. Mention one major cause responsible for the decline in tiger population.
2. Write one main effort of the biodiversity conservationists that must have helped in the increase in tiger population.