NCERT Exemplar Class 12 Biology Solutions Chapter 15 Biodiversity and Conservation

NCERT Exemplar Class 12 Biology Solutions Chapter 15 Biodiversity and Conservation

Edited By Priyanka kumari | Updated on Aug 26, 2022 03:59 PM IST | #CBSE Class 12th
Upcoming Event
CBSE Class 12th  Exam Date : 15 Feb' 2025 - 15 Feb' 2025

NCERT exemplar Class 12 Biology solutions chapter 15 is a very important topic to study for your Board exams conducted by CBSE. Our trained professionals who have experience in Biology over years have prepared the solutions of NCERT very carefully to guide the students perfectly. NCERT exemplar Class 12 Biology solutions chapter 15 provides easy and accurate solutions for NCERT questions that are prepared to serve students for better and easier understanding of different concepts. The examples and solutions provided by our experts are fully reliable and can be accessed offline in pdf format through NCERT exemplar Class 12 Biology solutions chapter 15 pdf download that makes it easier for students to study and learn.

This Story also Contains
  1. Introduction to NCERT Exemplar Class 12 Biology Chapter 15 Biodiversity and its Conservation
  2. NCERT Exemplar Class 12 Biology Solutions Chapter 15- Multiple Choice Questions:
  3. Very Short Answer Type Questions:
  4. Short Answer Type Questions:
  5. Long Answer Type Questions:
  6. Major Subtopics in NCERT Exemplar Class 12 Biology Solutions Chapter 15 Biodiversity and Its Conservation
  7. NCERT Exemplar Class 12 Biology Solutions Chapter 15 Biodiversity and its Conservation– Learning Outcomes
  8. NCERT Exemplar Class 12 Biology Chapter Wise Links:
  9. NCERT Exemplar Class 12 Solutions Subject Wise:

Introduction to NCERT Exemplar Class 12 Biology Chapter 15 Biodiversity and its Conservation

Lesson 15 of biology, biodiversity and its conservations covers various and all components and aspects of biodiversity that has been defined as the most crucial part of ecosystem important for maintaining a balance around the ecosystem. The NCERT exemplar Class 12 Biology chapter 15 solutions covers all the terms associated with bio diversity that has been defined as the sum total of diversity existing at all levels together.

Class 12 Biology NCERT exemplar solutions chapter 15 not only covers all the components and factors of biodiversity but also the need and importance of biodiversity along with means and ways to conserve and safeguard it in nature.

NCERT Exemplar Class 12 Biology Solutions Chapter 15- Multiple Choice Questions:

Question:1

Which of the following countries has the highest biodiversity?
a. South America
b. South Africa
c. Russia
d. India

Answer:

The answer is the option (a) Brazil
Explanation: This country falls in the area of Amazon rainforest, which is having the highest biodiversity in the world.

Question:2

Which of the following is not a cause for loss of biodiversity?
a. Destruction of habitat
b. Invasion by alien species
c. Keeping animals in zoological parks
d. Over-exploitation of natural resources

Answer:

The answer is the option (c) Keeping animals in zoological parks
Explanation: Keeping animals in zoological parks helps in conservation of biodiversity. It gives a natural and safe environment with supervision to check their decreasing numbers.

Question:3

Which of the following is not an invasive alien species in the Indian
context?

a. Lantana
b. Cynodon
c. Parthenium
d. Eichhornia

Answer:

The answer is the option (b) Cynodon
Explanation: Other species from the options were introduced into India from some other parts of the world. Cynodon has yet not introduced or spotted in India.

Question:4

Where among the following will you find pitcher plant?
a. The rain forest of North-East India
b. Sunderbans
c. The Thar Desert
d. Western Ghats

Answer:

The answer is the option (a) Rainforest of North-East India
Explanation: Pitcher plants are spotted in the rainforest of North-East India because the moist and humid climate is favourable to them.

Question:5

Which one of the following is not a major characteristic feature of
biodiversity hot spots?

a. A large number of species
b. An abundance of endemic species
c. Mostly located in the tropics
d. Mostly located in the polar regions

Answer:

The answer is the option (c) mostly located in the polar regions
Explanation: Polar Regions have the poorest biodiversity because of low sunlight, very low temperature and negligible precipitation.

Question:6

Match the animals given in column I with their location in column II:

Column IColumn II
A. Dodoi. Africa
B. Quaggaii. Russia
C. Thylacineiii. Mauritius
D. Stellar’s sea cowiv. Australia
Choose the correct match from the following:
a. A-i, B-iii, C-ii, D-iv
b. A-iv, B-iii, C-i, D-ii
c. A-iii, B-i, C-ii, D-iv
d. A-iii, B-i, C-iv, D-ii

Answer:

The answer is the option (d) (i)-(c), (ii)-(a), (iii)-(d), (iv)-(b)

Question:7

What is common to the following plants: Nepenthes, Psilotum, Rauwolfia and Aconitum?
a. All are ornamental plants
b. All are phylogenic link species
c. All are prone to overexploitation
d. All are exclusively present in the Eastern Himalayas.

Answer:

The answer is the option (c) All are prone to over exploitation
Explanation: These plants have various medicinal uses in traditional medicines and hence they are exploited and prone to increased exploitation.

Question:8

The one-horned rhinoceros is specific to which of the following sanctuary
a. Bitar Kanika
b. Bandipur
c. Kaziranga
d. Corbett park

Answer:

The answer is the option (c) Kaziranga
Explanation: Kaziranga national park is renowned for providing shelter to one-horned rhinoceros.

Question:9

Amongst the animal groups given below, which one appears to be more
vulnerable to extinction?

a. Insects
b. Mammals
c. Amphibians
d. Reptiles

Answer:

The answer is the option (c) Amphibians
Explanation: At present, 33% of all amphibian species face the threat of extinction.

Question:10

Which one of the following is an endangered plant species of India?
a. Rauwolfia serpentina
b. Santalum album (Sandalwood)
c. Cycas beddonei
d. All of the above

Answer:

The answer is the option (d)All of these

Question:11

What is common to Lantana, Eichhornia and African catfish?
a. All are endangered species of India.
b. All are keystone species.
c. All are mammals found in India.
d. All the species are neither threatened nor indigenous species of India

Answer:

The answer is the option (d) All the species are neither threatened nor indigenous species of India.
Explanation: All the species are neither threatened nor indigenous species of India.

Question:12

The extinction of passenger pigeon was due to:
a. Increased number of predatory birds.
b. Overexploitation by humans.
c. Non-availability of the food.
d. Bird flu virus infection.

Answer:

The answer is the option (b) Overexploitation by humans.
Explanation: Passenger pigeons were native birds to North America. They became extinct due to excessive hunting.

Question:13

Which of the following statements is correct?
a. Parthenium is an endemic species of our country.
b. African catfish is not a threat to indigenous catfishes.
c. Steller’s sea cow is an extinct animal.
d. Lantana is popularly known as carrot grass.

Answer:

The answer is the option (c) Steller’s sea cow is an extinct animal.

Question:14

Among the ecosystem mentioned below, where can one find maximum
biodiversity?

a. Mangroves
b. Desert
c. Coral reefs
d. Alpine meadows

Answer:

The answer is the option (c) Coral reefs
Explanation: Mangroves and alpine meadows can support only a selected number of species. The same condition is in deserts as well.

Question:15

Which of the following forests is known as the ‘lungs of the planet Earth’?
a. Taiga forest
b. Tundra forest
c. Amazon rain forest
d. Rain forests of North East India

Answer:

The answer is the option (c) Amazon rain forest

Question:16

The active chemical drug reserpine is obtained from:
a. Datura
b. Rauwolfia
c. Atropa
d. Papaver

Answer:

The answer is the option (b) Rauwolfia
Explanation: Rauwolfia extract is used in developing the drug serpentine.

Question:17

Which of the following group exhibit more species diversity?
a. Gymnosperms
b. Algae
c. Bryophytes
d. Fungi

Answer:

The answer is the option (d) Fungi
Explanation: Among plants, angiosperms and fungi show the largest number of species.

Question:18

Which of the below-mentioned regions exhibit less seasonal variations?
a. Tropics
b. Temperates
c. Alpines
d. Both (a) & (b)Solution:

Answer:

The answer is the option (a) Tropics
Explanation: Tropics get the same amount of illumination throughout the year and hence there is less seasonal variation.

Question:19

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

a. CITES Convention
b. The Earth Summit
c. G-16 Summit
d. MAB Programme

Answer:

The answer is the option (b) The Earth Summit

Question:20

What is common to the techniques (i) in vitro fertilisation, (ii) Cryo
preservation and (iii) tissue culture?

a. All are in situ conservation methods.
b. All are ex-situ conservation methods.
c. All require ultra-modern equipment and large space.
d. All are methods of conservation of extinct organisms

Answer:

The answer is the option (b) All are ex-situ conservation methods.
Explanation: Option (a) can be easily ruled out. Tissue culture does not require large space and hence option (c) can be ruled out. Extinct organisms cannot be conserved, so option (d) can be ruled out.

Very Short Answer Type Questions:

Question:1

What characteristics make a community stable?

Answer:

Following characteristics make a community stable:
(a) Least variation in productivity from year to year
(b) Resistance to occasional disturbances
(c) Resistance to invasion by alien species

Question:2

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

Answer:

Following are the reasons for mass extinctions of species in the past:
(a) Natural disturbances
(b) Alien invasion

Question:3

What accounts for the greater ecological diversity of India?

Answer:

Following are the reasons for greater ecological diversity of India:
(a) Low Latitude: Biodiversity is higher in lower latitudes than in higher latitudes
(b) Presence of rainforests and deciduous forests in the country
(c) Presence of mountain forests

Question:5

What does ‘Red’ indicate in the IUCN Red List (2004)?

Answer:

It indicates extinct species.

Question:6

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

Answer:

The number of species, which thrive in biodiversity hotspots, is extremely high. Hence, protection of biodiversity hotspots alone can reduce up to 30% the current rate of species extinction.

Question:7

What is the difference between endemic and exotic species?

Answer:

A species, which is confined to a particular geographical area, is called endemic to that area. On the other hand, a species, which has been introduced into a geographical area from some other area, is called exotic species.

Question:8

How does species diversity differ from ecological diversity?

Answer:

Ecological Diversity
(i) It shows the diversity in terms of type ecosystem in a geographical area.
(ii) Presence of rainforest, desert, deciduous forests, etc. in India is an example of ecological diversity.
Species Diversity
(i). It shows diversity in terms of species under a particular genus.
(ii) Presence of many species of frogs an example of species diversity.

Question:9

Why is genetic variation important in the plant Rauwolfia vomitoria?

Answer:

The plant Rauwolfia vomitoria produce various chemicals with medicinal properties. This could be possible because of genetic variation in Rauwolfia. Moreover, genetic variation also indicates towards richer biodiversity.

Question:10

What is Red Data Book?

Answer:

The IUGN releases Red List to show the number of extinct and endangered species. Different countries also release their own version of this list; which is usually termed as Red Data Book.

Question:11

Define gene pool.

Answer:

The set of all gene in a population of a particular species is called gene pool of that species.

Question:12

What does the term ‘Frugivorous’ mean?

Answer:

A fruit-eating animal is called ‘Frugivorous,’ e.g. monkeys.

Question:13

What is the expanded form of IUCN?

Answer:

International Union for the Conservation of Nature.

Question:14

Define the terms (i) Bioprospecting (ii) Endemism

Answer:

(i) Bioprospecting: The process of discovery and commercialization of new products; based on biological resources; is called bioprospecting.
(ii) Endemism: Certain geographical regions have a high prevalence of endemic species. This phenomenon is called endemism.

Question:15

What is common to the species shown in figures A and B?


Answer:

Both are invasive weed species.

Question:16

What is common to the species shown in figures A and B?



Answer:

Both the figures A and B are examples of Keystone species. A species, which has a very high impact on its environment and the impact, is disproportionate to its numerical strength; is called a keystone species.

Short Answer Type Questions:

Question:1

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

Answer:

Earlier mass extinctions were caused by natural disturbances. However, current mass extinction is happening because of fabricated interventions by human beings. Loss of habitat for a large number of organisms is because of human interventions.

Question:2

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.

Answer:

In my opinion, habitat loss and fragmentation are the major cause for the loss of biodiversity. Loss of habitat is mainly brought about by humans, through deforestation and pollution. Humans have cleared more than 50% of the Amazon rainforest. Since Amazon rainforest is richest in biodiversity; reduced forest cover in this region has led to a great loss of biodiversity. This speaks about the huge impact, which habitat loss and fragmentation can have on biodiversity.

Question:3

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

Answer:

Let us take the example of an insect. Let us assume that it plays an important role in the pollination of many plants. If the insect becomes extinct, that will mean a problem for those plants, which depend on this insect for pollination. Those plants will not be able to produce seeds and may become extinct in due course of time. After the extinction of those plants, any species, which depend on them for food, will be left with limited resources for food. This shows that the extinction of even a single species can prove disastrous for the whole ecosystem.

Question:4

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?

Answer:

While considering a large area to assess the species-area curve, we need to understand the advantages offered by a large area. A larger area means more resources and thus a higher number of plants. This will provide more food to sustain more individuals. Thus, it will result in a greater number of species than what is possible in a confined area. This explains the occurrence of the steeper slope when we draw a species-area curve for a large area.

Question:5

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

Answer:

A climax community is a community in which productivity and diversity are constant. It takes millions of years for a community to progress from the primary stage to the climax stage. A period of one hundred years is just a small part of the timeline of community succession. Hence, in most of the cases, a community can easily maintain constancy of productivity and diversity over a time of hundred years.

Question:6

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

Answer:

Following are the reasons for greater biodiversity in tropical/subtropical regions:
(a) Tropical regions have remained undisturbed during the course of evolution on Earth. However, temperate regions had been subject to frequent glaciations in the past. This provided ample scope for evolution for the organisms in the tropical regions. This could have led to greater biodiversity in the tropical region.
(b) Tropical environment remains more or less constant throughout the year.
(c) More solar energy is available in tropical regions. This helps in higher productivity in this region, which sustains a diverse set of organisms.

Question:7

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

Answer:

Conventional methods are not sufficient to identify and assess many prokaryotic species. Scientists are yet to discover many species of bacteria, which are living on this Earth. Without complete knowledge of all the species present, it is not possible to properly assess the biodiversity of bacteria.

Question:8

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

Critical dispensation is one of the population dynamics that can be used in categorizing a species as threatened. It is a mathematical model and is used to categorize a species as threatened. When the population of a species reaches to such a low level that it is unable to sustain itself; this level is called a critical dispensation. Once the population reaches this level, it faces the threat of extinction.

Question:9

What could be the possible explanation for the greater vulnerability of amphibians to extinction as compared to other animal groups?

Answer:

The scientist has yet to understand the proper cause for large scale extinction of amphibians. Some of the possible reasons might include disease, habitat destruction and modification, exploitation, pollution, pesticide use, exotic species and ultraviolet-B radiation. Their complex reproductive need may be one of the causes of the high vulnerability of amphibians to extinction.

Question:10

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

Answer:

Scientists take the following steps to estimate the total number of species on Earth:
(a) Selecting an exhaustively studied group of insects.
(b) Comparing its number of species in tropics with that in subtropics.
(c) Extrapolating this ratio to estimate the number of other species.
(d) Finally, the total estimate about the number of species on Earth is made.

Question:11

Humans benefit from the diversity of life. Give two examples.

Answer:

Following are the two benefits which human beings derive from biodiversity:
(a) We get food, medicines, raw materials, wood, etc. from nature, and this is possible because of biodiversity.
(b) Biodiversity helps in maintaining the ecosystem. A healthy ecosystem is beneficial for all of us.

Question:12

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

Two major causes (other than anthropogenic causes) for the loss of biodiversity are as follows:
(a) Glaciations and Global warming: The Earth had been through many phases of glaciations and global warming. Mammoths are believed to have existed during the Ice Age. Global
warming led to the end of the Ice Age, which resulted in mass extinction.
(b) Meteor hit: Dinosaurs are believed to have become extinct because of meteor hit.

Question:13

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

Answer:

A species, which has been categorized by IUCN Red List as likely to become extinct, is called an endangered species. Examples are:
Platanthera praeclara (a type of orchid) is an endangered plant.
Panthera pardus Orientalis (a type of leopard) is an endangered animal.

Question:14

What are sacred groves and their role in biodiversity conservation?

Answer:

In many tribal areas, a part of the forest is set aside. All the plants and animals in this part are worshipped, and no harm is done to them. This part is called a sacred grove. Sacred grove helps in creating awareness about biodiversity conservation. This consciousness has been passed down through generations to tribal people. This has definitely helped the tribal in the conservation of flora and fauna around their dwelling.

Question:15

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

Answer:

For studying coral reefs, one should go to the coast along Tamil Nadu. For mangrove vegetation, one should go to the southern tip of West Bengal. For estuaries, one should go and travel through the backwaters of Kerala.

Question:16

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

Answer:

It is definitely true that more solar energy is available in the tropics. Sunlight falls directly at the tropics. Because of straight illumination, the duration of the day is longer at the tropics than at higher latitudes. Due to this, plenty of sunlight is available in the tropics. Better availability of solar energy results in higher productivity that is evident from the rich biodiversity in this region.

Question:17

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

Answer:

When a species becomes extinct, then plants and animals, which were obliquely dependent on it, also become extinct in due course of time. This phenomenon is called coextinction. If a fish becomes extinct, then many parasites, which got sustenance from the fish, become extinct. Many predators for which this fish was the main source of food would also become extinct.

Long Answer Type Questions:

Question:1

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

Answer:

When an alien species is introduced into an area accidentally or on purpose, it may become invasive and threaten other species. Invasive species can be a serious competitor, competing for the same resources. It can also turn out to be a predator for some species. There are many examples of invasive species, which played havoc with the local biodiversity. Some examples are as follows: -
(a) Water Hyacinth: Water Hyacinth is originally from the Amazon basin. It has proved to be invasive species in many countries. This plant grows at a rapid rate and covers the whole pond and lake. By covering the surface of the pond, this plant reduces the supply of sunlight and oxygen to the bottom of the pond. Thus, it proves detrimental for other organisms in the pond.
(b) Parthenium or Carrot Grass: This plant came as contaminant along with imported wheat from America. This plant proved to be highly invasive in India. This notorious breed becomes a big problem for farmers in India.

Question:2

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

Answer:

We know that human interventions have hastened the loss of biodiversity, and loss of habitat is a major cause for this. Reducing the loss of habitat can help in preventing the loss of biodiversity. Following steps can be taken to achieve this:
(i) Reduce: Reducing consumption of various items is essential. Reduction in demand will help in reducing the demand for natural resources. This will help in reducing deforestation and thus will help in preventing the loss of biodiversity.
(ii) Reuse: Reusing old items whenever possible. Old containers can be used for keeping household items. Reuse also helps in reducing the drain of natural resources.
(iii) Recycle: I will recycle various items. For example, an old newspaper can be used for making papier mache items. Old and discarded clothes can be used for making shopping bags and curtains.
Apart from reducing the drain on natural resources, the above-mentioned three Rs also help in minimizing pollution. If pollution can be checked, it will surely help in protecting biodiversity.

Question:3

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

Answer:

An ecosystem works on continuous exchange and interdependencies among various components. All living beings depend on various abiotic factors to obtain raw material and energy. Producers depend on soil, air and sunlight to produce food. Primary consumers depend on producers for food. Secondary consumers depend on primary consumers for food. Now let us consider the following scenario.
Imagine two herbivores A and B. Animal A can feed on a variety of plants, while animal B can feed on only one plant. If the sole plant that is eaten by animal B is somehow wiped out from the area, then animal B will also face extinction. However, loss of a few plant species will not pose any danger to the existence of animal A. This shows the advantage of diversity in terms of available plants for animal A.
The above logic applies to other organisms as well. This means that if there is rich biodiversity in the ecosystem, then primary and secondary productivity is at an optimum level. This helps in maintaining stability in the ecosystem.

Question:4

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

Answer:

Modern man is capable of doing many activities that were not possible by earlier species of hominid. Following examples illustrate this suitably:
(a) Modern man began agriculture. The land was cleared to make way for farming. This changed the climate in a dramatic way. Farming also increased the level of conflict between humans and wildlife.
(b) Modern man began industries and developed various infrastructures. Many natural resources began to be exploited to promote industrialization and construct buildings. This not only resulted in the exploitation of forests and wildlife but also created pollution. All of this disturbed the wildlife. Clearing large tracts of forest area to make habitat for human beings is very common these days.
(c) Railways revolutionized the way we travel. But trains are a big cause for loss of habitat and life for many wild animals.

Question:5

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

Answer:

The product of ecosystem processes is called ecosystem service. Following is the list of four important ecosystem service:
(a) Purification of air and water
(b) Rainfall
(c) Pollination of crops
(d) Assimilation of excess carbon
There should be no charge for ecosystem services because nature provides everything free. However, there should be proper attempts to estimate the cost of these services. Data about the costs of these services should be made available to the public. Every person should be educated about the real value of ecosystem services. This will help us in appreciating the real value of services that we get from the ecosystem.

Question:6

Describe the consumptive use value of biodiversity as food, drugs and medicines, fuel and fibre with suitable example

Answer:

Consumptive Use Value: Many natural products are consumed at the local level by human beings. However, we neither sell nor buy these products. These products do not make a direct contribution to the nation’s economy. The value of these products is called consumptive use value of biodiversity.
(a) We pay for almost all the food we consume, but we do not pay for the soil, water and air
which play an important role in food production.
(b) Many naturally occurred herbs are used for their medicinal use by indigenous people. In most of the cases, people do not need to pay for using such plants. This also shows the consumptive use-value.
(c)Almost 2.4 million people all over the world use firewood for cooking and heating. People who use firewood do not need to pay for that. Had they been using some other fuel; they would have paid some money for that. This shows consumptive use-value of firewood.
(d) In a rural area, people often use naturally growing fibre plants for making ropes and other useful items. They do not pay for the fibre. This shows consumptive use-value of fibre.

Question:7

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

Answer:

Following are the reasons for greater species diversity near the equator than at the poles. The equator receives direct illumination and hence has experienced uniform climatic conditions throughout the history of evolution. Stable conditions near the equator have given rise to a large number of species. When we consider about the temperate regions, the climatic conditions have changed dramatically in these regions. Many species, which lived in these regions, become extinct during dramatic climatic changes. Hence, we find a lower number of species in these regions. In polar regions, due to extreme cold climatic condition and less availability of sunlight species diversity is very less.

Question:8

Explain briefly the ‘rivet popper hypothesis’ of Paul Ehrlich.

Answer:

Paul Ehrlich gave the ‘rivet’ (species) popper hypothesis’, which can be explained as follows:
(a) An airplane has thousands of rivets which are important for joining different parts of the plane.
(b) Some rivets are more important (key species) than others because they may be present on a part which is structurally crucial (has major ecosystem function) for airplane.
(c) If a person takes out a rivet from a seat to keep it as a memento (causing a species to extinct); nothing is going to happen to the airplane. Even if subsequent passengers take out all the rivets from a seat, the only damage will be the collapse of that particular seat.
(d) If a person takes out a rivet from the wing of the aircraft (key species), there can be some issue of stability during flight. If all the rivets form the wing are taken out, then the flight will end in a disastrous crash.
This analogy shows that if an organism is highly crucial for an ecosystem, then its extinction can spell doom for the ecosystem.

Question:9

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

Answer:

Species richness in any area depends on various factors. Some of them are as follows:
(a) Balance between immigration and extinction
(b) Rate and magnitude of disturbance in small area Vs large area
(c) Predator-prey dynamics
(d) Clustering of individuals of the same species because of dispersal limitations.
When the area increases up to a certain extent, the number of species increases, as shown by the graph, this can happen because of the reduced rate of disturbance and because of favourable predator-prey dynamics. Once the area increases beyond the threshold level, there is no growth in the number of species. This can happen because of dispersal limitations.

Major Subtopics in NCERT Exemplar Class 12 Biology Solutions Chapter 15 Biodiversity and Its Conservation

  • 15.1 Biodiversity
  • (i) Genetic Diversity
  • (ii) Species Diversity
  • (iii) Ecological Diversity
  • 15.1.1 How Many Species are there on Earth and How Many in India?
  • 15.1.2 Patterns of Biodiversity
  • (i) Latitudinal Gratitudes
  • (ii) Species-Area relationships
  • 15.1.3 The importance of Species Diversity to the Ecosystem
  • 15.1.4 Loss of Biodiversity
  • (i) Habitat loss and fragmentation
  • (ii) Over exploitation
  • (iii) Alien species invasions
  • (iv) Co-extinctions
  • 15.2 Biodiversity Conservation
  • 15.2.1 Why Should We Conserve Biodiversity?
  • 15.2.3 How to conserve Biodiversity?
Pearson | PTE

Register now for PTE & Unlock 20% OFF : Use promo code: 'C360SPL20'. Valid till 30th NOV'24! Trusted by 3,500+ universities globally

NCERT Exemplar Class 12 Biology Solutions Chapter 15 Biodiversity and its Conservation– Learning Outcomes

Class 12 Biology NCERT exemplar solutions chapter 15 will teach students about the various aspects of biodiversity and the factors associated with it. In NCERT exemplar solutions for Class 12 Biology chapter 15, students will also learn about the emerging issues and need of loss of biodiversity and what all could be done to conserve the biodiversity present around us. The lesson will also enlighten students about different components of biodiversity, their relationship, and their importance in creating a balance in biodiversity.

The NCERT exemplar Class 12 Biology solutions are prepared by professionals practicing in this field for over years that will help students to understand different concepts and methods easily through their guidance. They are precise and have been formulated with proper review and guidelines from CBSE to enhance learning and scoring for examinations.

NCERT Exemplar Class 12 Biology Chapter Wise Links:

Important Topics in NCERT exemplar Class 12 Biology Solutions Chapter 15

Chapter 15 of Biology, biodiversity and its conservation solutions have been provided by our experts so that they can learn anywhere hassle free. NCERT exemplar Class 12 Biology solutions are a perfect way to learn briefly about biodiversity and its conservation including some of the main topics including the meaning of biodiversity, different types of biodiversity, types of biodiversity patterns, importance of diversity in ecosystem, loss of biodiversity and its causes.

NCERT exemplar Class 12 Biology solutions chapter 15 also covers the issue and importance of biodiversity conservation and different methods used and employed to conserve biodiversity.

NCERT exemplar solutions for Class 12 Biology chapter 15 briefly deals with biodiversity, their survival and its conservation with respect to mankind. There are more than 1.5 million species present around the world that have diversified life forms on earth forming a part of biodiversity.

NCERT Exemplar Class 12 Solutions Subject Wise:

Check NCERT solutions for questions given in the book:

NEET Highest Scoring Chapters & Topics
Most Scoring concepts For NEET (Based On Previous Year Analysis)
Download EBook

Also, Read NCERT Solution subject wise

Must Read NCERT Notes subject wise

Also Check NCERT Books and NCERT Syllabus here

Frequently Asked Questions (FAQs)

1. What are some of the important topics to cover from this chapter?

The chapter is important to study for your Board examination and NCERT exemplar Class 12 Biology solutions chapter 15 gives apt and precise solutions to questions.

2. Is this material available offline?

Yes, the material available on our site can be accessed online as well as offline through NCERT exemplar class 12 Biology solutions chapter 15 pdf download in pdf form free of cost.

3. Are NCERT exemplar Class 12 Biology chapter 15 solutions reliable for study of Board examination?

Yes, the solutions have been carefully formed and reviewed by experts that have practiced in biology for over years and are formed keeping in mind the marking scheme and guidelines of CBSE

Articles

Upcoming School Exams

Application Date:04 November,2024 - 03 December,2024

Application Date:04 November,2024 - 03 December,2024

Application Date:06 November,2024 - 03 December,2024

Application Date:06 November,2024 - 03 December,2024

View All School Exams

Explore Top Universities Across Globe

Questions related to CBSE Class 12th

Have a question related to CBSE Class 12th ?

Hello there! Thanks for reaching out to us at Careers360.

Ah, you're looking for CBSE quarterly question papers for mathematics, right? Those can be super helpful for exam prep.

Unfortunately, CBSE doesn't officially release quarterly papers - they mainly put out sample papers and previous years' board exam papers. But don't worry, there are still some good options to help you practice!

Have you checked out the CBSE sample papers on their official website? Those are usually pretty close to the actual exam format. You could also look into previous years' board exam papers - they're great for getting a feel for the types of questions that might come up.

If you're after more practice material, some textbook publishers release their own mock papers which can be useful too.

Let me know if you need any other tips for your math prep. Good luck with your studies!

It's understandable to feel disheartened after facing a compartment exam, especially when you've invested significant effort. However, it's important to remember that setbacks are a part of life, and they can be opportunities for growth.

Possible steps:

  1. Re-evaluate Your Study Strategies:

    • Identify Weak Areas: Pinpoint the specific topics or concepts that caused difficulties.
    • Seek Clarification: Reach out to teachers, tutors, or online resources for additional explanations.
    • Practice Regularly: Consistent practice is key to mastering chemistry.
  2. Consider Professional Help:

    • Tutoring: A tutor can provide personalized guidance and support.
    • Counseling: If you're feeling overwhelmed or unsure about your path, counseling can help.
  3. Explore Alternative Options:

    • Retake the Exam: If you're confident in your ability to improve, consider retaking the chemistry compartment exam.
    • Change Course: If you're not interested in pursuing chemistry further, explore other academic options that align with your interests.
  4. Focus on NEET 2025 Preparation:

    • Stay Dedicated: Continue your NEET preparation with renewed determination.
    • Utilize Resources: Make use of study materials, online courses, and mock tests.
  5. Seek Support:

    • Talk to Friends and Family: Sharing your feelings can provide comfort and encouragement.
    • Join Study Groups: Collaborating with peers can create a supportive learning environment.

Remember: This is a temporary setback. With the right approach and perseverance, you can overcome this challenge and achieve your goals.

I hope this information helps you.







Hi,

Qualifications:
Age: As of the last registration date, you must be between the ages of 16 and 40.
Qualification: You must have graduated from an accredited board or at least passed the tenth grade. Higher qualifications are also accepted, such as a diploma, postgraduate degree, graduation, or 11th or 12th grade.
How to Apply:
Get the Medhavi app by visiting the Google Play Store.
Register: In the app, create an account.
Examine Notification: Examine the comprehensive notification on the scholarship examination.
Sign up to Take the Test: Finish the app's registration process.
Examine: The Medhavi app allows you to take the exam from the comfort of your home.
Get Results: In just two days, the results are made public.
Verification of Documents: Provide the required paperwork and bank account information for validation.
Get Scholarship: Following a successful verification process, the scholarship will be given. You need to have at least passed the 10th grade/matriculation scholarship amount will be transferred directly to your bank account.

Scholarship Details:

Type A: For candidates scoring 60% or above in the exam.

Type B: For candidates scoring between 50% and 60%.

Type C: For candidates scoring between 40% and 50%.

Cash Scholarship:

Scholarships can range from Rs. 2,000 to Rs. 18,000 per month, depending on the marks obtained and the type of scholarship exam (SAKSHAM, SWABHIMAN, SAMADHAN, etc.).

Since you already have a 12th grade qualification with 84%, you meet the qualification criteria and are eligible to apply for the Medhavi Scholarship exam. Make sure to prepare well for the exam to maximize your chances of receiving a higher scholarship.

Hope you find this useful!

hello mahima,

If you have uploaded screenshot of your 12th board result taken from CBSE official website,there won,t be a problem with that.If the screenshot that you have uploaded is clear and legible. It should display your name, roll number, marks obtained, and any other relevant details in a readable forma.ALSO, the screenshot clearly show it is from the official CBSE results portal.

hope this helps.

Hello Akash,

If you are looking for important questions of class 12th then I would like to suggest you to go with previous year questions of that particular board. You can go with last 5-10 years of PYQs so and after going through all the questions you will have a clear idea about the type and level of questions that are being asked and it will help you to boost your class 12th board preparation.

You can get the Previous Year Questions (PYQs) on the official website of the respective board.

I hope this answer helps you. If you have more queries then feel free to share your questions with us we will be happy to assist you.

Thank you and wishing you all the best for your bright future.

View All

A block of mass 0.50 kg is moving with a speed of 2.00 ms-1 on a smooth surface. It strikes another mass of 1.00 kg and then they move together as a single body. The energy loss during the collision is

Option 1)

0.34\; J

Option 2)

0.16\; J

Option 3)

1.00\; J

Option 4)

0.67\; J

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times.  Assume that the potential energy lost each time he lowers the mass is dissipated.  How much fat will he use up considering the work done only when the weight is lifted up ?  Fat supplies 3.8×107 J of energy per kg which is converted to mechanical energy with a 20% efficiency rate.  Take g = 9.8 ms−2 :

Option 1)

2.45×10−3 kg

Option 2)

 6.45×10−3 kg

Option 3)

 9.89×10−3 kg

Option 4)

12.89×10−3 kg

 

An athlete in the olympic games covers a distance of 100 m in 10 s. His kinetic energy can be estimated to be in the range

Option 1)

2,000 \; J - 5,000\; J

Option 2)

200 \, \, J - 500 \, \, J

Option 3)

2\times 10^{5}J-3\times 10^{5}J

Option 4)

20,000 \, \, J - 50,000 \, \, J

A particle is projected at 600   to the horizontal with a kinetic energy K. The kinetic energy at the highest point

Option 1)

K/2\,

Option 2)

\; K\;

Option 3)

zero\;

Option 4)

K/4

In the reaction,

2Al_{(s)}+6HCL_{(aq)}\rightarrow 2Al^{3+}\, _{(aq)}+6Cl^{-}\, _{(aq)}+3H_{2(g)}

Option 1)

11.2\, L\, H_{2(g)}  at STP  is produced for every mole HCL_{(aq)}  consumed

Option 2)

6L\, HCl_{(aq)}  is consumed for ever 3L\, H_{2(g)}      produced

Option 3)

33.6 L\, H_{2(g)} is produced regardless of temperature and pressure for every mole Al that reacts

Option 4)

67.2\, L\, H_{2(g)} at STP is produced for every mole Al that reacts .

How many moles of magnesium phosphate, Mg_{3}(PO_{4})_{2} will contain 0.25 mole of oxygen atoms?

Option 1)

0.02

Option 2)

3.125 × 10-2

Option 3)

1.25 × 10-2

Option 4)

2.5 × 10-2

If we consider that 1/6, in place of 1/12, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

Option 1)

decrease twice

Option 2)

increase two fold

Option 3)

remain unchanged

Option 4)

be a function of the molecular mass of the substance.

With increase of temperature, which of these changes?

Option 1)

Molality

Option 2)

Weight fraction of solute

Option 3)

Fraction of solute present in water

Option 4)

Mole fraction.

Number of atoms in 558.5 gram Fe (at. wt.of Fe = 55.85 g mol-1) is

Option 1)

twice that in 60 g carbon

Option 2)

6.023 × 1022

Option 3)

half that in 8 g He

Option 4)

558.5 × 6.023 × 1023

A pulley of radius 2 m is rotated about its axis by a force F = (20t - 5t2) newton (where t is measured in seconds) applied tangentially. If the moment of inertia of the pulley about its axis of rotation is 10 kg m2 , the number of rotations made by the pulley before its direction of motion if reversed, is

Option 1)

less than 3

Option 2)

more than 3 but less than 6

Option 3)

more than 6 but less than 9

Option 4)

more than 9

Back to top