Chapter-16

Biodiversity and Conversation

1. Multiple choice questions.

Question 1(i).

Conservation of biodiversity is important for:

(a) Animals

(b) Animals and plants

(c) Plants

(d) All organisms.

Answer:

(d) All organisms

Question 1(ii).

Threatened species are those which:

(a) Threaten others

(b) Lion and tiger

(c) Are abundant in number

(d) Are suffering from the danger of extinction.

Answer:

(d) Are suffering from the danger of extinction

Question 1(iii).

National parks and sanctuaries are established for the purpose of:

(a) Recreation

(b) Hunting

(c) Pets

(d) Conservation.

Answer:
(d) Conservation

Question 1(iv).

Biodiversity is richer in:

(a) Tropical Regions

(b) Polar Regions

(c) Temperate Regions

(d) Oceans.

Answer:

(a) Tropical Regions

Question 1(v).

In which one of the following countries, the ‘Earth Summit’ was held?

(a) The UK

(b) Mexico

(c) Brazil

(d) China.

Answer:

(c) Brazil.

2. Answer the following questions in about 30 words.

Question 2(i).

What is biodiversity?

Answer:

Biodiversity itself is a combination of two words, Bio (life) and diversity (variety). In
simple words, biodiversity is the number and variety of organisms found within a
specified geographic region. It refers to the varieties of plants, animals and
microorganisms, the genes they contain and the ecosystems they form. It relates to
the variability among living organisms on the earth, including the variability within
and between the species and that within and between the ecosystems.

Question 2(ii).
What ‘are the different levels of biodiversity?

Answer:

Biodiversity itself is a combination of two words, Bio (life) and diversity (variety).

In simple words, biodiversity is the number and variety of organisms found within a
specified geographic region. It is a result of hundreds of millions of years of
evolutionary history. Biodiversity can be discussed at three levels:

1. Genetic diversity;

2. Species diversity;

3. 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 its richness, abundance and types.

3. Ecosystem diversity: The broad differences between ecosystem types and the
diversity of habitats and ecological processes occurring within each ecosystem type
constitute the ecosystem diversity.

Question 2(iii)

What do you understand by ‘hotspots’?

Answer:

Some areas are richer in species than others. Areas rich in species diversity are
called hotspots of diversity. Hotspots are defined according to their vegetation.
Plants are important because these determine the primary productivity of an
ecosystem. Most, but not all, of the hotspots rely on species-rich ecosystems for
food, firewood, cropland, and income from timber. In Madagascar, for example, about
85 per cent of the plants and animals are found nowhere else in the world.

Question 2(iv).

Discuss briefly the importance of animals to human kind.

Answer:

The earth, its ecosystems, and its creatures are all deeply connected. Thus, the
existence of many species depends on the survival of others, and don’t think human
beings are an exception. As disconnected from nature as many of us humans have
become, there are many animals we rely on for our benefit and wellbeing. Many
animals actually help people just by performing their natural roles in their
environment. And we’re benefiting from their services for free.
Question 2(v).

What do you understand by ‘exotic species’?

Answer:

Species which are not the natural inhabitants of the local habitat but are introduced
into the system, are called exotic species. There are many examples when a natural
biotic community of the ecosystem suffered extensive damage because of the
introduction of exotic species. During the last few decades, some animals like tigers,
elephants, rhinoceros, crocodiles, minks and birds were hunted mercilessly by
poachers for their horn, tusks, hides, etc. It has resulted in the rendering of certain
types of organisms as endangered category.

3. Answer the following questions in about 150 words.

Question 3(i).

What are the roles played by biodiversity in the shaping of nature?

Answer:

Species of many kinds perform some function or the other in an ecosystem. Nothing
in an ecosystem evolves and sustains without any reason. It implies that every
organism, besides extracting its needs, also contributes something of useful to other
organisms. Human beings contribute a great deal to the sustenance of ecosystems.

1. 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.

2. The more diverse an ecosystem, better are the chances for the species
to survive through adversities and attacks, and consequently, is more
productive.

3. Hence, the loss of species would decrease the ability of the system to
maintain itself. Just like a species with a high genetic diversity, an
ecosystem with high biodiversity may have a greater chance of adapting
to environmental change.

4. In other words, the more the variety of species in an ecosystem, the

more stable the ecosystem is likely to be.

Question 3(ii).

What are the major factors that are responsible for the loss of biodiversity? What
steps are needed to prevent them?

Answer:
Major causes for loss of biodiversity are as follows:

1. Since the last few decades, growth in human population has increased
the rate of consumption of natural resources. It has accelerated the loss
of species and habitation in different parts of the world.

2. Over-exploitation of resources and deforestation have become rampant

to fulfil the needs of large population. As these tropical rain forests
contain 50 per cent of the species on the earth, destruction of natural
habitats have proved disastrous for the entire biosphere.

3. Natural calamities such as earthquakes, floods, volcanic eruptions,

forest fires, droughts, etc. cause damage to the flora and fauna of the
earth, bringing changes to the biodiversity of respective affected
regions.

4. Pesticides and other pollutants such as hydrocarbons and toxic heavy

metals destroy the weak and sensitive species.

5. Conservation strategy has suggested the following steps for biodiversity

conservation:

a. Efforts should be made to preserve the species that are

endangered.

b. Prevention of extinction requires proper planning and

management.

c. Varieties of food crops, forage plants, timber trees,

livestock, animals and their wild relatives should be
preserved;

d. Each country should identify habitats of wild relatives and

ensure their protection.

e. Habitats where species feed, breed, rest and nurse their

young ones should be safeguarded and protected.

f. International trade in wild plants and animals be regulated.