Biodiversity And Conservation

Question 1

What is biodiversity and it was popularized by whom?

Answer 1

The term biodiversity means the sum total of diversity that exists at all levels of biological
organization.


The term biodiversity is popularized by the sociobiologist, Edward Wilson.

Question 2

Explain the three important components of biodiversity with examples
?

Answer 2

Genetic diversity, species diversity and ecological diversity are the three important components
of biodiversity

1. Genetic diversity

 The variation of genes within the species is known as genetic diversity.
Examples
a) The medicinal plant
Rauwolfia vomitoria growing in different Himalayan ranges
produce different varieties of active chemical
reserpine.
b)
India has more than 50,000 genetically different strains of rice and 1000 varieties of
mango.

2. Species diversity

The occurrence of different variety of species within a region is called species diversity.
Example
;-
The Western Ghats have greater number of amphibian species than Eastern Ghats.
3. Ecological diversity

Diversity at the level of community and ecosystem is known as ecological diversity.

Example
;-
India has greater ecosystem diversity in deserts, rain forests, mangroves, coral reefs, wet
lands, estuaries and alpine meadows than the country like Norway

Question 3

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

Answer 3


It is difficult to answer that how many species are there on the earth.

According to IUCN the total number of animals and plant species is more than 1.5 million.

It is doubtful that how many of the species are yet to be discovered and described.

Biologists often make statistical comparison of the temperate tropical species richness of the
studied group of insects and tried to calculate this ratio to other group of plants and animalsin
order to provide gross estimate of the total number of species on earth.

According to
Robert May, total global species biodiversity is around 7 million

Question 4

The figure given below represents the global biodiversity of major taxa of invertebrates,
vertebrates and plants. Study the figure and list out your conclusions.?

Answer 4

More than 70% of all the species recorded are animals. Plants include up to 22% of the total.
Among animals, insects are the most species rich taxonomic group, making up more than 70%
of the total. That is out of 10 animals on the planet 7 are insects.

Among vertebrates, fishes constitute the largest diversity group.

Among plants, fungi and angiosperms are the largest diversity group.

In the plant kingdom, the fungi species is more than the combined total species of the
amphibians, reptiles and mammals

Question 5

Comment on the biodiversity of India?

Answer 5



India is one of the 12 mega diversity countries of the world.
India shares about 8.1% of the global species diversity even though India has only 2.4% of the
world’s land area.

Nearly 45,000 species of plants and twice the number of animals have been recorded in India.

According to Robert May’s global estimates, in India only 22% of the total species have been
recorded so far.

As per the above estimate, there are 100,000 species of plants and 300,000 species of animals
yet to be discovered and described.

Question 6

PATTERNS OF BIODIVERSITY

Answer 6

Two patterns of biodiversity are present
I.Lattitudinal gradients
II.
Species area relationship

Question 7

Explain latitudinal gradient in biodiversity?

Answer 7


The diversity of plants and animals is not uniform throughout the world but shows a rather
uneven distribution.

The most well known gradient in diversity is latitudinal gradient.

In general, species diversity decreases as we move away from the equator towards the poles.

With very few exceptions, tropics (latitudinal range of 23.5
0 N to 23.50 S) harbor more species
than temperate or polar areas

Question 8

The tropical region of earth is rich in species diversity than temperate or polar regions. Explain
this statement with examples?

Answer 8

 Colombia, located near the equator has nearly 1400 species of birds while New York at 41
0 N
has 105 species and Green land at 71
0 N has only 56 species.

India, with much of its land area in the tropical region has more than 1200 species of birds.

The tropical Amazonian rain forest in South America has the greatest biodiversity on earth. It is
home to more than 40,000 species of plants, 3,000 species of fishes, 1,300 species of birds, 427
species of mammals, 427 species of amphibians, 378 species of reptiles and more than 1,25,000
species of invertebrates.

Question 9

What are the reasons for great species diversity or species richness in the tropical regions?

Answer 9

 Tropical regions have remained relatively undisturbed for millions of years and thus had a
long time for species diversification.

Tropical environments are less seasonal, relatively more constant and predictable.

Availability of more solar energy in this region contributes much productivity.

Question 10

Explain species area relationship in biodiversity?

Answer 10

The great German Naturalist and Geographer
Alexander Von Humboldt observed that within
a region species richness increased with increasing explored area, but only up to a limit

The relation between species richness and area for a wide variety of taxa such as angiosperm
plants, birds, bats, freshwater etc turns out to be a rectangular hyperbola.

On a logarithmic scale, the relationship is a straight line described by the equation,
Log S = log C + Z log A
Where, S = species richness
C = Y intercept
Z = slope of the line (regression coefficient)
A = Area

Question 11

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

Answer 11


Ecologists have discovered that the value of Z lies in the range of 0.1 to 0.2 regardless of the
taxonomic group or the region.

But, if we analyse the species area relationship among very large areas like the entire
continents, we will find the slope of the line to be much steeper; that is Z values in the range of
0.6 to 1.2.

For example, for frugivorous (fruit eating) birds and mammals in the tropical forest of different
continents, the slope is found to be 1.15

Question 12

Rich biodiversity is not only essential for the ecosystem health but important for the very
survival of the human race on this planet. Explain this statement on the basis of ‘Rivet poper
hypotheses

Answer 12

 Survival of each and every species on this earth is important for the survival of the other
species.

One might think, what will happen if one species of tree frog of Western Ghats become extinct?
The answer for this question can be well explained with
‘Rivet poper hypotheses of Stanford
ecologist
Paul Ehrlich.

Ehrlich, compared ecosystem to an aeroplane.

In an aeroplane all parts are joined together using thousands of rivets.

The rivets are compared to species of the ecosystem.

If every passenger travelling in it starts to popping a rivet to take home (causing a species to
become extinct) it may not affect flight safety initially (proper functioning of the ecosystem)

As more and more rivets are removed, the plane become dangerously weak over a period of
time
 Furthermore, which rivet is removed may also be critical. Loss of rivets on the wings (key
species that drives major ecosystem function) is obviously a more serious threat to flight safety
than loss of a few rivets on the seats or windows inside the plane.

Question 13

The biological wealth of our planet has been declining rapidly and the accusing finger is clearly
pointing to human activities”. How far this statement is true?. Explain your answer with the
present situation of loss of biodiversity.

Answer 13

 The accelerated rates of species extinction that the world is facing now are greatly due to
human activities.

The colonization of tropical Pacific Islands led to the extinction of more than 2,000 species of
native birds.

As per IUCN Red list, 784 species extinct in the last 500 years. This include 338 vertebrates, 359
invertebrates and 87 plants.

Some examples of recent extinctions include the dodo (Mauritius), quagga (Africa) , thylacine
(Ausralia), Styeller’s sea cow (Russia) and 3 sub species of tiger (Bali, Javan, Caspian).

Currently, 15,500 species world wide are facing the threat of extinction.

Presently 12% of all bird species, 32% of all amphibian species, 23% of all mammal species and
31% of all gymnosperm species in the world face the threat of extinction.

The current species extinction rates are estimated to be 100 to 1000 times faster than in the prehuman times and our activities are responsible for the faster rates.

Ecologist warns that if the present trends continue, nearly half of all the species on earth might
be wiped out within the next 100 years.

Question 14

What are the causes of biodiversity losses or species losses in a geographical region ?
OR what
are “The Evil Quartlet”of biodiversity losses?

Answer 14

1.
HABITAT LOSS AND FRAGMENTATION

2. OVER EXPLOITATION
3. ALIEN SPECIES INVASIONS
4. CO-EXTINCTIONS

Question 15

Why should we conserve biodiversity?
OR How is biodiversity important for ecosystem
functioning?

Answer 15

The reasons for conserving biodiversity can be grouped into 3 categories.
1.
Narrowly utilitarian
2.
Broadly utilitarian
3.
Ethical argument

Question 16

Narrowly utilitarian

Answer 16

 This argument for conserving biodiversity is obvious; humans derive countless economic
benefits such as food, firewood, fibre, construction materials, industrial products (tannins,
dyes, lubricant, resins, and perfumes) and medicinal products etc.

More than 25% of medicines are derived from plants and nearly 25,000 species of plants
contribute to the traditional medicines used by the native people around the world.

Nobody knows how many more medicinally useful plants there are in tropical rain forests
waiting to be explored.

Question 17

Broadly utilitarian

Answer 17



This argument says that biodiversity plays a vital role in all ecosystem services.
Amazon rain forest alone produces 20% of the total oxygen in the atmosphere through
photosynthesis.
The other indirect benefits that we receive are,
a) Pollination:
Without pollination the plants cannot give us fruits and seeds. The
pollination is done by bees, birds, bats etc.
b)
Aesthetic and cultural benefits
 The aesthetic value includes
ecotourism, bird watching, wildlife, pet keeping,
gardening etc.

Walking through a forest, watching spring flowers in full bloom or walking up to a
bulbul’s song in the morning etc. also give pleasure.

Question 18

Ethical argument

Answer 18

This argument says that we have a moral responsibility to take care of earth’s biodiversity
such as millions of plants, animals, microbes etc. with whom we share the planet.
 We need to realize the philosophically or spiritually that each and every species on the earth
has its own intrinsic value.

Question 19

How do we conserve biodiversity?

Answer 19

The ecosystem is changed by natural as well as man made disturbances. So it is very important
to take necessary steps to conserve biodiversity effectively and efficiently to prevent further
destruction or degradation of habitats.

It is our duty to look after our planet, protect it and pass it on to coming generation without
any damage.
Conservation of biodiversity can be done by two ways.
1.ex situ conservation
2.In situ conservation

Question 20

In situ conservation

Answer 20

 The conservation of genetic resources through their maintenance within natural or even
human made ecosystem in which they occur is called in situ conservation.

In – situ includes protection of a group typical ecosystem through a network of protected
areas.

The areas of land or sea which are meant for the protection and maintenance of biodiversity
are called
protected areas.

Examples for protected areas are
National parks, sanctuaries, biosphere reserves, cultural
landscapes, natural monuments, hot spots, sacred groves et

Question 21

In situ conservation examples

Answer 21

.hotspots
. biosphere reserves
.national parks
. wildlife sanctuary
.sacred groves

Question 22

Ex situ conservation

Answer 22

The conservation of organisms outside their habitats such as Zoos ,botanical gardens ,wildlife
safari parks,
Cryopreservation
 It is a method of ex situ conservation in which the gametes of threatened species are preserved
in viable and fertile condition for long periods using cryopreservation technique.(the storage
of materials at very low temperature)

Eggs can be fertilized in vitro and plants can be propagated using tissue culture methods.

Seeds of different genetic strains of commercially important plants can be kept for long
periods in seed banks.
”The Earth Summit”
held in Rio de Janero in 1992
, called upon all nations
to take appropriate measures for conservation of biodiversity and sustainable utilization of its
benefits. The
World Summit On Sustainable Development
held in 2002 in Johannesburg
,
South Africa
in the current rate of biodiversity loss at global, regional and local levels.
, 190 countries pledged their commitment to archive by 2010, a si

Question 23

Among the ecosystem services there are control of floods and soil erosion. How is this achieved
by the biotic components of the ecosystem?

Answer 23

 The basic method of flood control includes
.reforestation,
.construction of dams,
. reservoirs,
.
artificial channel
which divert flood water etc.


Soil erosion is controlled by
•.growing a variety of plants or grasses on the bare land,
•agro
forestry (planting trees among the agricultural crops),
•minimum cultivation etc.

Question 24

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

Answer 24

 The great
•structural and
•resource heterogeneity provided by plants
is the principal reason of
high animal diversity.
 A single plant can accommodate many animal species.

Question 25

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

Answer 25

 If a particular species is extinct due to any activity, it will affect the existence of other related
plants and animals.

 Example is the relationship between CALVARIA TREE and DODO.

Question 26

As a biology student ,can you agree starting a multinational company in Eravikulam offering
employment of 20000 people?

Answer 26

•
We can agree if the company will not alter the biodiversity of that area
•
They should be eco friendly also
•
There must be no pollution.
•
Use only biodegradable substances

Question 27

Our wild life resources are depleting very fast .Suggest possible measures to check the same?

Answer 27

1. Strict legal measures must be given to the poachers. Aware about the depleting wildlife
   resources.
2. By protecting the ecosystem like biosphere reserves, national parks, sanctuaries etc.

Question 28

Biodiversity has some aesthetic and cultural values. Substantiate?

Answer 28

• The aesthetic values include ecotourism, bird watching, wild life, pet keeping, gardening
etc.
•
Plants like tulsi ,peepal etc are considered as sacred and are used by many Indians for
religious purposes
•
Several birds and snakes are considered as sacred
•
Naga temples are common in India.
•
Today plants and animals are recognized as symbols of national pride and cultural heritage.

Question 29

“Biodiversity conservation in India is up to the mark” Do you agree?

Answer 29

•
In my view, it is not up to the mark. Because,
1.
We are not controlling pollution.
2.
Population growth may lead to shortage on land or habitation.
3.
Not giving awareness to people
4.
Laws are not strictly followed

Question 30

Hotspots

Answer 30

Hot spots are the 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)

Now there are 34 biodiversity hot spots in the world.

Western Ghats and Sri Lanka, Indo-Burma and Himalayacovers our country’s high
biodiversity regions.

Eastern himalayas and Western Ghats are the hot spots of Kerala
 Even though hot spots cover less than 2% of the total earth’s land area, they accommodate
extremely high number of species.
 They also reduce the ongoing mass extinction by almost 30%.

Question 31

Biosphere reserves

Answer 31

These are protected areas of land or coastal environments to conserve the ecosystem and the
genetic resources within the ecosystem.

India has 14 Biosphere Reserves.

Agasthyamalai and part of Nilgiris are the biosphere reserves in kerala.

Question 32

National park

Answer 32

A national park is an area which is strictly reserved for the welfare of the wild life where
activities such as cultivation, grazing etc. are strictly prohibited.

India has 90 national parks.

The first national park of india is Jim Corbet National Park Of Uttar Pradesh

Question 33

Wildlife sanctuary

Answer 33

The area in which protection is given only to animals is called sanctuary.

India has 448 wildlife sanctuaries.

Periyar sanctury in Kerala protects a wide range of wild life

Question 34

Sacred groves

Answer 34

What are sacred groves? What is their role in conservation?)

These are forests protected by tribal communities, which are free from all disturbances.

Tribal give religious sanctity to the forest.

The flora and fauna is well protected here.

Cutting of trees is not done for commercial purposes.

Sacred groves are the last refuges for a large number of rare and threatened species
E.g. ., forests of Karnataka, Maharashtra, Meghalaya and the traditional “
sarpakavu” of Kerala

Question 35

Habitat loss and fragmentation

Answer 35

1.
Habitat loss and fragmentation
 It is due to cutting down of trees, ploughing a grassland, filling a wetland or burning a
forest.

The best example is the tropical rain forest. Once the forest covered the 14% of earth’s
land. Now it covers only 6%.

The Amazonian rain forest, the
lungs of the planet,
harboring millions of species is being
cut for cultivating
soya beans or for conversion to grasslands for raising
beef cattle.

The fragmentation of the forest i.e., broken down into small fragments due to human
activities also led to the disappearance of many species.

Question 36

Over exploitation

Answer 36

 Biodiversity satisfies all the human needs. But when need turns to greed, it leads to the
over exploitation of nature and natural resources.

The extinction of
Steller’s sea cow and passenger pigeon were due to over exploitation by
humans.

Question 37

Alien species invasions
(Introduction of exotic species is one of the major threats to biodiversity. Substantiate?)

Answer 37


New species entering a geographical region are known as
exotic or alien species.

Introduction of alien species to a new habitat may adversely affect the native species.
Some time it may leads to the extinction of the species.
 For example, the
Nile perch introduced into Lake Victoria in east Africa led to the
extinction of 200 species
cichlid fish
in the lake.

Carrot grass (Parthenium), Lantana
and water hyacinth
(
eicchornia) is also alien invasive
species that destroyed the environment.

The introduction of African cat fish
Clarias gariepinus
for aquaculture purpose is posing a
threat to the native cat fishes.

The introduction of American cockroach,
Periplaneta americana into india with food
ships has replaced the native cockroach
Blatta orientalis

Question 38

Co extinction

Answer 38


When a species extinct, the animal or plant associated with it also extinct. This is known as
co-extinction.

For example, the extinction of a host fish leads to the extinction of parasites associated
with it.