Bihar Board - Class 12 Biology - Chapter 15: Biodiversity and Conservation Short Answer Question

1. Ecologists have discovered that the value of Z lies in the range of 0.1 to 0.2 regardless of taxonomic group or region. When will the slope of the line be steeper in a species-area relationship? 

Ans: Regardless of taxonomic group or region, the ecologists have discovered that the value of Z lies in the range of 0.1 to 0.2  the slope of a line is much steeper if one analyzes the species-area relationship among very large areas such as entire continents. 

2. Define cryopreservation. Why is it useful in conserving biodiversity? 

Ans: Cryopreservation is preserving material in liquid nitrogen at -196oC. It is useful in conserving biodiversity because it can be done to preserve threatened species in viable and fertile conditions for a long period. 

3. What is the reason for genetic variation shown by medicinal plant Rauwolfia Vomitoria? 

Ans: Genetic variation might be in terms of potency and concentration of the active chemical reserpine produced by medicinal plants. 

4. What are hot spots? 

Ans: Hot spots are the priority areas of conservation that are extremely rich in species that have high endemism and are under constant threat of extinction. 

5, What is cryopreservation? 

Ans: Cryopreservation is a technique used in the storage of materials at an ultra-low temperature either by rapid cooling or by grade cooling and simultaneous dehydration at very low temp. 

6. What do you mean by “vulnerable species”? 

Ans: Species that are believed to move into the category of endangered species shortly if the causal factors continue operating are called vulnerable species. 

7. Explain co-extinction with a suitable example. 

Ans: Coextinction refers to the disappearance of a species with the extinction of another species of plant or animal with which it was associated in an obligatory way. e.g., Plant-pollinator mutualism. 

8. What is the IUCN red list? Give any two uses of this list? 

Ans: IUCN (International Union of Conservation of Nature and Natural Resources) maintains a “Red data list” which is a catalog of taxa facing the risk of extinction. The main uses of this list are as follows: 

i) It helps to identify and document the species with a high risk of extinction. 

ii) Also helps to provide awareness to the degree of threat to biodiversity. 

9.“Species diversity of plants is much less than that of animals” Why? 

Ans: The species diversity of plants is much less than that of animals because most animals possess nervous systems that control and coordinate various activities of animals. They also possess receptors to receive environmental stimuli; some of these responses are adaptive and ensure the survival of organisms in changing environmental conditions. 

10.“The Amazonian rainforest in South America has the greatest biodiversity on earth”. Justify the statement. 

Ans: The greatest biodiversity on earth is found in the amazonian rainforest in South America. The Amazonian rainforest is the birthplace of about 40000 species of plants, 1,25,000 species of insects, 3000 species of fishes, 427 amphibians, 378 reptiles, 1300 birds, and 427 mammals.