Loss of Biodiversity

Q. When Pisaster was removed from an enclosed intertidal area of the American Pacific Coast, more than 10 species of ____(i)_______became extinct because of ____(ii)_______.

1. (i) - vertebrates, (ii) - intraspecific competition
2. (i) - invertebrates, (ii) - interspecific competition
3. (i) - vertebrates, (ii) - interspecific competition
4. (i) - invertebrates, (ii) - intraspecific competition

Q.

What is the definition of natural selection?

Q.

How does diversity enrich our lives?

Q. According to Darwin's theory of natural selection, the individuals that tend to survive are those that have

1. Characteristics their parents acquired by use and disuse
2. The greatest number of offspring
3. Large body size
4. Variations best suited to environmental conditions

Q. The historic convention on Biological Diversity held in Rio de Janeiro in 1992 is known as:

1. CITES Convention
2. The Earth Summit
3. G–16 Summit
4. MAB Programme

Q.

___ results in depletion of wildlife.

Q.

What is common to Lantana, Eichhornia, and African catfish?

1. All are keystone species

2. All the endangered species of India

3. All the species are neither threatened nor indigenous species of India

4. All mammals found in India

Q.

Which one is an example of alien species?

1. Introduction of water hyacinth into India

2. Introduction of Nile perch into Lake Victoria in East Africa

3. Introduction of African catfish into Indian rivers

4. All of the above

Q. During the period since the origin and diversification of life on earth, there have been episodes of mass extinction.

1. three
2. four
3. five
4. six

Q.

Quite a few species of plants and animals are endangered in India. Why?

Q.

A taxon which is facing an extremely high risk of extinct in the wild in immediate future is known as

1. Vulnerable

2. Critically endangered

3. Rare

4. Exotic

Q. The ‘Earth Summit’ held at Rio de Janeiro in 1992 resulted in

1. compilation of red list
2. establishment of biosphere reserves
3. convention on biodiversity
4. development of hotspots

Q. What is true regarding background extinction?

1. Calculated from widespread events that wipes out the majority of living plants and animals.
2. The extinction of individual species due to natural environmental or ecological factors.
3. Calculated from rate of extinction that occurred before homo sapiens appeared on Earth.
4. Species going extinct once every thousand years.

Q. Choose the correct statement(s) regarding the Amazon rainforest.
I. It is called the lungs of the planet.
II. It harbours probably millions of species.
III. It is the largest tropical rainforest in South America and has the greatest biodiversity on earth.
IV. They are being cut and cleared for cultivating soya beans or for the conversion to grasslands for raising beef cattle.

1. Only II, III and IV
2. Only I and II
3. Only I, II and III
4. I, II, III and IV

Q.

Why should we conserve biodiversity ? How can we do it ? [5]

Q.

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

Q. Which among the following statements is a part of Darwin's theory of evolution on the basis of natural selection?

1. Acquired characteristics that are inherited are the driving force of evolution
2. Clutch size or number of offspring is not related to fitness
3. There is high chance of survival if more offspring are produced
4. Nature always selects the largest and strongest

Q.

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

Q.

A new species X is introduced into a forest. How is it likely to affect the local species of that area?

Q. Assertion: Alien species invasion is the leading cause of species extinction

Reason: The ‘Evil Quartet’ is a sobriquet for biodiversity conservation

1. Both assertion and reason are true and the reason is the correct explanation of the assertion
2. Assertion is true but the reason is false
3. Both assertion and reason are false
4. Both assertion and reason are true but the reason is not the correct explanation of the assertion

Q. Assertion :Evolution is not a directed process in sense of determinism. Reason: Evolution is a stochastic process based on chance events in nature and chance mutation in the organisms.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. What are the threatened species? Give example any two such species.

Q. Natural selection really means:

1. Struggle for existence
2. Differential reproduction
3. Sexual selection
4. Survival of the fittest

Q. What will happen? If we go on cutting trees.

1. Biodiversity of many areas will be developed.
2. Biodiversity of many areas will be severely affected.
3. Both A and B.
4. None of the above.

Q. Which of the following is true about endangered species?

1. They can be threatened in the near future
2. They are species found in a particular region
3. They are at risk of getting extinct
4. They are also known as vulnerable species

Q. Mention the different threats of biodiversity.

Q. In stabilising selection

1. individuals with the mean value of the trait are favoured
2. individuals with the extreme value of the trait are favoured
3. individuals with the mean value of the trait are eliminated
4. Both a and b

Q. Habitat loss and habitat fragmentation cause loss of biodiversity and even lead to species extinction.

1. False
2. True

Q.

What name is given to those species.
That has died out completely?

Q. Name the three important components of biodiversity.