2nd PUC Biology Question Bank Chapter 15 Biodiversity and Conservation

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Karnataka 2nd PUC Biology Question Bank Chapter 15 Biodiversity and Conservation

2nd PUC Biology Biodiversity and Conservation One Mark Questions and Answers

Question 1.
What are sacred species?
Answer:
Traditionally conserved species of plants and animals which are of religious or cultural importance are called sacred species.

Question 2.
Define species diversity.
Answer:
Species diversity refers to variety of species within the region i.e., the species richness of an area.

Question 3.
What is Biosphere?
Answer:
The portion of the earth and its atmosphere inhabited by living organisms.

Question 4.
What is a buffer Zone?
Answer:
It is a part of biosphere reserve which lies in the middle and surrounds the core zone. It is managed to accommodate a greater variety of resources and support educational activities and research.

Question 5.
Define Endemic species?
Answer:
A species native to particular region and found nowhere else in the world is called as endemic species.

Question 6.
Name any four animals that Indians respect as sacred species.
Answer:

Elephant
Cobra
Peacock
Monkey

Question 7.
Name any 2 sacred plants with their scientific name.
Answer:
(a) Peepal tree – Ficus religiosa.
(b) Tulsi – ocimum sanctum.

Question 8.
What are threatened species?
Answer:
The species who are in the danger of becoming extinct in the near future due to decreasing population are called threatened species.

Question 9.
What is biodiversity?
Answer:
The variety and variability of living organisms is known as biodiversity.

Question 10.
What is a sacred grove?
Answer:
A patch of trees protected in the name of God is called sacred groves.

Question 11.
Who proposed the term biodiversity?
Answer:
Walter G. Rosen.

Question 12.
What is species richness?
Answer:
It is the number of species in a unit area.

Question 13.
What is alpha biodiversity?
Answer:
Alpha diversity refers to the diversity of organisms in the same community or habitat. (It is therefore intra-community diversity). This type of diversity is represented by a combination of species richness and species evenness.

Question 14.
What is beta diversity?
Answer:
Species undergo frequent changes when the habitat or environmental conditions get changed. Due to this a given area may be replaced by some other species. The rate of replacement of N species along a gradient of habitats or communities is called beta diversity (It is therefore inter-community diversity).

Question 15.
What is Gamma biodiversity?
Answer:
Diversity of the habitats over the total landscape or geographical area is called gamma diversity. Ecosystem diversity describes the number of niches, tropic levels and various ecological processes that support energy flow, food webs and the recycling of nutrients. It focuses on various biotic interactions, the role and function of keystone species.

Question 16.
What are alien species?
Answer:
These species are exotic species that are introduced from a foreign country.

Question 17.
What is IUCN?
Answer:
International Union for Conservation of Nature.

Question 18.
What is an extinct species?
Answer:
These species no longer exist. For e.g., dinosaurs.

Question 19.
What are critically endangered or CE species?
Answer:
They have a high probability of extinction in the wild. They can become extinct in 2 generations or 5, years if they are not protected.

Question 20.
What are endangered species or E species?
Answer:
These species have a probability of extinction in 20 years of 10 generations.

Question 21.
What is vulnerable or VU species?
Answer:
These taxa have a 10% probability of becoming extinct in 100 years.

Question 22.
What is insitu method of biodiversity conservation?
Answer:
Conservation steps taken in natural ecosystems like a forest is called insitu conservation (in there natural habitat)

Question 23.
What is exsitu conservation of biodiversity?
Answer:
In this method of conservation, organisms are conserved outside their natural habitats like animals in a zoo or plants in a botanical garden.

Question 24.
What is a sacred forest?
Answer:
It is a forest area where the flora and fauna are totally protected in the name of local deities.

Question 25.
Name any two biosphere reserves of India.
Answer:
The Nilgiris and Sunderbans.

Question 26.
What are ecological pyramids?
Answer:
The graphical representation of different trophic levels in an ecosystem is called as an ecological pyramid.

Question 27.
Give an example for ex-situ conservation.
Answer:
Zoological parks/botanical gardens/widlife safari.

Question 28.
What is endemism?
Answer:
The species which are confined to a specific geographical region and not found elsewhere.

Question 29.
What are biodiversity hotspots?
Answer:
Hot spots are the regions with very high levels of species richness and high degree of endemism and also regions of accelerated habitat loss.

2nd PUC Biology Biodiversity and Conservation Two Marks Questions and Answers

Question 1.
Name the three important components of biodiversity.
Answer:

Genetic diversity
Species diversity and
Ecological/Ecosystem diversity.

Question 2.
How is biodiversity important for ecosystem functioning?
Answer:
Rich biodiversity

provides stability to the ecosystem
contributes to higher productivity and
essential for ecosystem health.

Question 3.
Define biodiversity. Write three forms of biodiversity.
Answer:
Biodiversity is the vast array of species of living organisms occurring on the earth and the ecological complexes of which they are a part.
Three forms of biodiversity:

Genetic diversity
Species diversity
Ecological diversity.

Question 4.
Write the major causes of biodiversity losses.
Answer:
Major causes of biodiversity losses:

Habitual loss and fragmentation
Over-exploitation
Alien species invasions
Co-extinctions.

Question 5.
What are sacred grooves? Give an example.
Answer:
The tracts of forest conserved and protected based on the religious faith ground:
Example: Khasi and Jaintia Hills in Meghalaya.
Aravalli hills of Rajasthan.

Question 6.
What is primary productivity ? Give brief description of factors that affect primary productivity.
Answer:
Primary Productivity: The rate at which radiant energy is captured by the producers for the synthesis of energy rich organic compound through photosynthesis is called primary productivity. The factors affecting the primary productivity include temperature, soil moisture, nutrients and rainfall.

Question 7.
Write important features of a sedimentary cycle in an ecosystem.
Answer:
Sedimentary cycle

It acts as a reservoir of nutrients which are recycled in the earth’s crust.
There is no atmospheric phase in the cycle.

Question 8.
What are Alien species invasions? Explain with a suitable example.
Answer:
Alien species invasions: Intentional or chance introduction of exotic species info new islands or countries by man adversely affects the native species. The Nile perch introduced into Lake Victoria led to the extinction of more than 200 species of cichlid fish in the lake.

Question 9.
Explain why tropical regions show greater levels of biodiversity.
Answer:
Biodiversity is not uniform throughout the world but varies with change in latitude and altitude.
Favourable environmental conditions favour speciation and make it possible for a Target number of species to exist there; i.e., biodiversity is more in such areas than in others.

Question 10.
Write a short note on co-extinction?
Answer:
Co-extinctions: Co extinction of a species is the loss of one species upon the extinction of another. An example is the case of a coevolved plant-pollinator. Mutualism where extinction of one invariably leads to the extinction of the other.

2nd PUC Biology Biodiversity and Conservation Three Marks Questions and Answers

Question 1.
Write the difference between insitu and exsitu conservation:
Answer:
Insitu conservation :
1. It is the process of protecting the endangered species of plants or animals in the natural habitat either by protecting or cleaning up the habitat itself or by defending the species from predations.

2. It helps in recovering population in the surroundings where they have developed their distintive features.
Example : National Park, Biosphere reserves, wildlife sanctuaries.

Exsitu conservation :
1. It is the process of protecting endangered species of plants or animal by removing them from the unsafe or threatened habitat and placing them under the care of humans.

2. It helps in recovering populations preventing their extinction under stimulated conditions
that closely resemble their natural habitats.
Example : Botanical gardens, zoos, seed pollen banks, Gene banks etc.

Question 2.
Explain any three major causes of biodiversity loss.
Answer:
The major causes of biodiversity losses are:
(a) Habitat loss and fragmentation: Habitats are destroyed by many human activities. It is the ’ primary cause for loss of biodiversity of habitat. Human settlements, harbors, dams, reservoirs, roads, railway lines, industries, mines etc. , have reduced the natural habitats of wild life. Fragmentation develops barriers which limit potential of one species to colonize new areas.

The species now becomes more vulnerable to extinction by means of fire, wind and predators. Deforestation leads to decrease in population of species and also reduces the area of free movement of wild animals, and this may lower their reproductive capacity. Environmental pollution has degraded many important habitats, resulting in decrease in life.

(b) Over-exploitation : Humans have always depended on nature for food and shelter, but when’ need’ turns to ‘greed’, it leads to overexploitation of natural resources. Extinctions of Steller’s cow, passenger pigeon were due to over exploitation by humans.

(c) Alien species invasions: Intentional or chance introduction of exotic species info new islands or countries by man adversely affects the native species. The Nile perch introduced into Lake Victoria led to.the extinction of more than 200 species of cichlid fish in the lake.

(d) Co-extinctions: Co extinction of a species is the loss of one species upon the extinction of another. An example is the case of a coevolved plant-pollinator. Mutualism where extinction of one invariably leads to the extinction of the other.

2nd PUC Biology Biodiversity and Conservation Five Marks Questions Aand Answers

Question 1.
What are the causes for loss of biodiversity?
Answer:
The major causes of biodiversity losses are:
(a) Habitat loss and fragmentation: Habitats are destroyed by many human activities. It is the primary cause for loss of biodiversity of habitat. Human settlements, harbours, dams, reservoirs, roads, railway lines, industries, mines etc., have reduced the natural habitats of wild life. Fragmentation develops barriers which limit potential of one species to colonize new areas.

(b) Over-exploitation: Humans have always depended on nature for food and shelter, but when’ need’ turns to ‘greed’, it leads to overexploitation of natural resources. Extinctions of Steller’s cow, passenger pigeon were due to over exploitation by humans.

(c) Alien species invasions: Intentional or chance introduction of exotic species into new islands or countries by man adversely affects the native species. The Nile perch introduced into Lake Victoria led to the extinction of more than 200 species of cichlid fish in the lake.

(d) Co-extinctions: Co extinction of a species is the loss of one species upon the extinction of another. An example is the case of a coevolved plant-pollinator mutualism where extinction of one invariably leads to the extinction of the other.

(e) Disturbance and degradation: They are of two types, natural and manmade. Natural disturbance and degradation are caused by spontaneous jungle fire, pest infestation, defoliation by insects, locust attack, etc. Man-made disturbances and degradations are more severe. They include felling of trees, use of fire for clearing forest areas, collection of litter, and over-exploitation for other economically important products. Disturbance and degradation result in loss of biodiversity.

(f) Pollution: Excessive use of pesticides has polluted both ground water and surface water bodies. Many sensitive species have disappeared. There is tendency of pesticide biomagnification which results in higher concentration with the rise in trophic level. It has resulted in drastic decline in the population of fish eating birds and falcons. Run off from fertilizer rich fields eauses nutrient enrichment of water bodies.

The phenomenon is called eutrophication. There is an additional dense growth Of plants and animals followed by depletion oxygen, death of animals and fouling of water. Lead and other types of heavy metals poured into water bodies lead to mortality of many animals and birds.

(g) Intensive Agriculture: Spread of agriculture is at the cost of wetlands, grasslands and forests. Destruction of habitats results in extinction of species. Intensive agriculture leads to reduction in the genetic diversity. It increases the vulnerability of the crop plants to sudden attack by pathogens and pests.

(h) Wild life: Wild life resources provide aesthetic, recreational and economic benefits. It keeps the delicate balance of ecosphere. For example, many birds and insects are necessary for cross pollination of flowers. The healthy vegetation is also depending upon natural browsing and grazing, If many carnivores are killed, herbivores become dominant and there would be a predation pressure, which makes the “status of past” for crops.

In the last about 2000 years, the world has lost more than 160 species of mammals and birds which have became extinct and many others are becoming endangered species. Endangered and threatened species are due to various unfavorable factors and unprecedented interference by human beings.

(i) Forestry: There is a tendency to grow economically important trees in pure strands, e.g., Sal, Teak. It drives away or annihilates other species found in forests. Also pure Strands are liable to be attacked by insects and pathogens.

(j) Introduction of exotic species: Non-native or alien species are introduced for their economic and other uses. These species are considered to be the second major cause of extinction of some species (the first being habitat destruction). Island ecosystems are the most vulnerable due to their small number of species.

Question 2.
What are the uses of biodiversity?
Answer:
Mankind derives various benefits from the biological diversity existing around him. They are

(a) Economic benefit: These are direct in obtaining food, fibre, firewood, timber wood (for construction), gums, resins, tannins, rubber, pharmaceuticals etc.

(b) Drugs and Medicines: A number of drugs are based on plant products. Rosy periwinkle
(Catharanthus roseus: Vincarosea) yields alkaloids (vincristine and vinblastine) which are useful for treatment of leukaemia. Morphine (Papaver somniferum for pains ), quinine (from bark of Cinchona ledgeriana for malaria), taxel (from bark of Yew, Taxus brevifolia and Taxus baccata for treating cancers) etc.

(c) Aesthetic value: Biodiversity has a lot of aesthetic and attraction value, Ecotourism, bird watching, wildlife, pet keeping and gardening are all rewards of aesthetic value of biodiversity.

(d) Cultural benefit; Historically people have linked themselves with certain specific plants and animals. Majority of indian homes have specimens of Ocimum sanctum (Tulsi) growing in pots. Trees of Ficus religiosa (Peepal) and Prosopis cinerania (Khejri) are held sacred. They are planted and worshipped . Many birds and snakes are considered sacred and are worshipped.

(e) Ecological benefits or Ecosystem services: Forests and oceanic systems control climate and maintain the gaseous composition of the atmosphere. Oxygen is replenished through photosynthesis and carbon dioxide levels are lowered.

Storage and retention of rain waters of aquifers and reservoirs and maintenance and purification of water regimes . in soil and atmosphere is due to forests and vegetation. It helps in.control of floods and soil erosion. The ecosystem services are valued at 16 – 54 trillion dollars per year.

Question 3.
What is biodiversity? Describe its types, citing example for each.
Answer:
Biological diversity includes three hierarchical levels: Genetic diversity, species diversity and community or ecosystem diversity.

Genetic diversity: The number and nature of genes determine the characters of the organisms. No two individuals have exactly the same genetic makeup. This difference among the genes of two different organisms is called genetic diversity.

Species diversity: Species is a group of similar individuals, which are able to interbreed and produce fertile hybrids. All the members of a particular species have almost similar characters, but they differ markedly from the members of another species. This variation in the members of two different species in a region is called species diversity.

Community and ecosystem diversity: Genetic and species diversities finally give rise to community and ecosystem diversity. Diversity at the fevel of community and ecosystem has three perspectives.
1. Alpha diversity
2. Beta diversity and
3. Gamma diversity.

1. Alpha diversity: Alpha diversity refers to the diversity of organisms in the same community or habitat. (It is therefore intra-community diversity). This type of diversity is represented by a combination of species richness and species evenness.

2. Beta diversity: Species undergo frequent changes when the habitat or environmental conditions get changed. Due to this, a species in a given area may be replaced by some other species. The rate of replacement of species along a gradient of habitats or communities is called beta diversity (It is therefore inter-community diversity).

3. Gamma diversity: Diversity of the habitats over the total landscape or geographical area is called gamma diversity. Ecosystem diversity describes the number of niches, tropic levels and various ecological processes that support energy flow, food webs and the recycling of nutrients.

It focuses on various biotic interactions, the role and function of keystone species. Studies show that, diverse communities. are functionally more productive and stable. Even under changing environmental conditions, diverse communities exhibit greater stability.