CBSE Class 12 Biology Biodiversity and Conservation Worksheet Set E

Question. 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: C

Question. Match the animals given in column I with their location in column II.
Column I Column II
A. Dodo (i) Africa
B. Quagga (ii) Russia
C. Thylacine (iii) Mauritius
D. Stellar’s sea cow (iv) 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: D

Question. Which one of the following is an example of ex situ conservation?
(a) Wildlife sanctuary
(b) Seed bank
(c) Sacred groves
(d) National park

Answer: B

Question. Amongst the animal groups given below, which one appears to be more vulnerable to extinction?
(a) Insects
(b) Mammals
(c) Amphibians
(d) Reptiles

Answer: C

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

Answer: D

Question. Which one of the following pairs of organisms are exotic species introduced in India?
(a) Lantana camara, water hyacinth
(b) Water hyacinth, Prosopis cinereria
(c) Nile perch, Ficus religiosa
(d) Ficus religiosa, Lantana camara

Answer: A

Question. 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 over exploitation
(d) All are exclusively present in the Eastern Himalayas.

Answer : C 

Question. Which one of the following is not observed in biodiversity hot spots?
(a) Lesser inter-specific competition
(b) Species richness
(c) Endemism
(d) Accelerated species loss

Answer: A

Question. Biosphere reserves differ from National Parks and Wildlife Sanctuaries because in the former
(a) Human beings are not allowed to enter.
(b) People are an integral part of the system.
(c) Plants are paid greater attention than animals
(d) Living organisms are brought from all over the world and preserved for prosperity

Answer: B

Question. 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: D

Question. What is common to the techniques (i) in vitro fertilisation, (ii) Cryopreservation 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: B

Question. Which of the below mentioned regions exhibit less seasonal variations?
(a) Tropics
(b) Temperate
(c) Alpines
(d) Both (a) and (b)

Answer: A

Question. Which one of the following is not a major characteristic feature of biodiversity hot spots?
(a) Large number of species
(b) Abundance of endemic species
(c) Mostly located in the tropics
(d) Mostly located in the Polar Regions

Answer: C

Assertion Reason Questions:

a. Both assertion and reason are true and the given reason is the correct explanation
b. Assertion and reason both are true but given reason is not the correct explanation
c. Assertion is true, reason is false
d. Assertion is false, reason is true

Question. Assertion: Island ecosystems are generally prone to invasion by introduced species.
Reason: Invasion is common when the introduced ecosystem is not similar to the one in which the invader evolved.

Answer: C

Question. Assertion: Endemic organisms with limited range are the least affected by habitat destruction.
Reason: These organisms are not found anywhere else within the world and hence have more chance of recovering.

Answer: D

Question. Assertion: Speciation is a function of time and tropical regions had got a long evolutionary time for species diversification as compared to temperate regions.
Reason: Temperate regions have undergone frequent glaciations in the past whereas tropical regions have remained relatively undisturbed for millions of years.

Answer: A

Question. Assertion: Tropical rain forests are disappearing fast from developing countries.
Reason: No value is attached to these forests as they are poor in biodiversity.

Answer: C

Question. Assertion: Communities that comprise of more species tend to be more stable.
Reason: A higher number of species results in less variation in total biomass.

Answer: A

Short Answer Type Questions:

Question. Why certain regions have been declared as biodiversity “hot spots” by environmentalists of the world? Name any two “hot spot” regions of India.
Answer: Co-extinction refers to the disappearance of a species with extinction of another species ofplant or animal with which it was associated in an obligatory way.
Eg: Extinction of a plant species, when its pollinator species become extinct.

Question. List any four factors which may lead to loss of biodiversity.
Answer: Sacred groves are highly protected - because of religious and cultural traditions, refuges for large number of rare and threatened plants / ecologically unique and biodiversity rich regions.

Question. Many plant and animal species are on the verge of their extinction because of loss of forestland by indiscriminate use by the humans. As a biology student what method would you suggest along with its advantages that can protect such threatened species from getting extinct?
Answer: Biodiversity refers to the totality of genes, species and ecosystem of a region. It is a matter of concern because the biodiversity is important for our survival and well-being of
the planet.

Question. Why are sacred groves highly protected?
Answer: The introduction of Nile Perch into Lake Victoria in East Africa, led to the extinction Of more than 200 species of cichlid fish in the lake.
- Parthenium (carrot grass) introduced to our country have become invasive and caused environmental damage, and posing a threat to the native species.

Question. List the features that make a stable biological community.
Answer: Hot spots of biodiversity are the regions with very high levels of species richness and high degree of endemism. Environmentalists are in the opinion that the protection of hot
spots couldreduce the ongoing mass extinction by almost 30 per cent.
Two hot spot regions of India are: Western Ghats and Sri Lanka, and Indo-Burma.

Question. Suggest two practices giving one example of each, that help to protect rare or threatened species.
Answer: (a) Alexander Von Humboldt. He observed that with in a region species richness
Increased with increasing explored area, but only up to a limit.
(b) (1) Explored area is very small.
(2) Explored area is very large.
(c) When the area exhibit species richness.

Question.What is Mass extinction?
Answer: A large number of species become extinct due to natural calamities like volcanic eruptions,prolonged drought, heavy rain,earthquakes etc which is called mass extinction.

Question. Enlist the three levels of biodiversity with the help of suitable examples.
Answer: Narrow Utilitarian Aspect – Human derive direct benefit from nature in the form of food,firewood, medicine etc.
Broad Utilitarian Aspect- Biodiversity plays a major role in the ecosystem services that Nature provides - oxygen availability, pollination, aesthetic pleasure etc.
Ethical Aspect- Each species has its own intrinsic value. It is our moral duty to take care of well-being of plants and animals. We must conserve the present for the future of our children.

Question. Explain co- extinction with a suitable example.
Answer: (1) Habitat loss and fragmentation
(2) Over- exploitation of natural resources.
(3) Alien species invasions, which compete with the native species and cause theirextinction.
(4) Co-extinction of associated species in an obligatory way.

Question. What are the three basic arguments put forward regarding conservation of biodiversity?
Answer: In-situ conservation- It is an approach of conservation and protection of the whole ecosystem
and its biodiversity at all levels in order toprotect the threatened species. Endangered species is protected in itsnatural habitat.
E.g. National parks, Wild life sanctuaries, Biosphere reserves etc.
Ex-situ conservation- It is an approach of protecting the endangered species of plants and animals by removing it from the threatened habitat and placing under human care.
The endangered species is protected in places outside their natural habitats, E.g. Botanical gardens, Zoological parks, Seed banks etc.

Question. Differentiate between in-situ and ex-situ approaches of conserving biodiversity.
Answer: An endangered / threatened species can be conserved
1. genetic strains of commercially important plants can be preserved for a long time (seedbanks)
2. biodiversity loss is reduced
3. gametes of threatened species can be preserved in a viable and fertile condition for long periods (using cryopreservation)
4. eggs can be fertilized in -vitro
5. plants can be propagated using tissue culture
6. economically beneficial / conserve large number of species
7. aesthetic value 

Question. List six advantages of “ex-situ” approach to conservation of biodiversity.
Answer: Ex-situ conservation
Threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care
Botanical garden / tissue culture / micro propagation / seed bank /Zoological Park / wild life safari park /cryopreservation.

              Very Short Answer

Q1)       What kind of biodiversity is vital for the survival of mankind?

Q2)       Who popularised the term biodiversity?

Q3)       Define biodiversity?

Q4)       When and where the historic convention on biological diversity?

Q5)       Who estimated the conservative and scientifically sound?

              Short Answer

Q6)       What are the regions leads to the loss of biodiversity?

Q7)       What are the levels of the biological organisation?

Q8)       What are the various hypotheses proposed by the ecologists and evolutionary biologist?

Q9)       How can we conserve the biodiversity?

Q10)     What is the role of the conservation?

              Long Answer

Q11)     What are the causes of biodiversity losses?

Q12)     Difference between genetic diversity and species diversity?

Q13)     Explain the patterns of the biodiversity?

Q14)     State the difference between biodiversity and species richness?

Q15)     State the difference between in situ conservation and ex situ conservation?

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