CBSE Questions for Class 12 Medical Biology Biodiversity And Its Conservation Quiz 3 - MCQExams.com

$$\textbf{Correct option:}$$ (C)

$$\textbf{Explanation for correct option:}$$

$$\bullet$$ The accelerated rates of species extinction which the world is facing are mainly due to human activities.

$$\bullet$$ There are four major causes of loss of biodiversity ("The Evil Quartet)":

i) Habitat loss and fragmentation

ii) Over exploitation of natural resources 

iii) Alien species invasions

iv) Co- extinctions

$$\bullet$$ Zoological parks are the means of ex situ conservation of biodiversity in which animals are taken out from their natural habitat and placed in special setting where they are protected and given proper care.

$$\bullet$$ Hence, the correct option is (C)

• Gene banks are helping to preserve endangered species by storing the biological and genetic material of animals that are under threat of extinction. 
• Preserving species in their natural habit is the top priority, but gene banks are useful in two important ways:  

• Genetic diversity is the diversity in the number and types of genes present in different species and variations in the genes of the same species. 
• The greatest threat to genetic diversity in agricultural crops is introduction of high yielding varieties. 
• High yielding varieties contains the required traits and therefore are always bred purely. This reduces the genetic diversity within a particular species.

• Biodiversity hot spots are areas with high density of biodiversity or megadiversity. 
• The Western Ghats occur along the western coast of India for a distance of about 1600 km in Maharashtra, Karnataka, Tamil Nadu and Kerala extending over to Sri Lanka. 
• At low elevation up to 500 meters above sea level, the area contains tropical evergreen rain forests while semi-evergreen forests occur at a height of 500-1000 meters. 
• There is a high degree of endemism as well as the richness of species of flowering plants, amphibians, reptiles, some mammals and butterflies. It is the most biodiversity rich zone in India.

• When we conserve and protect the whole ecosystem, its biodiversity at all levels is protected. For example - we save the entire forest to save the tiger. This approach is called in-situ (on site) conservation. 
• Declaring national parks, wild life sanctuaries and biosphere reserves are various strategies for in-situ conservation.

• Bandipur in Karnataka state is the site of Bandipur National park, IUCN category II (national park), and Bengal tiger in Bandipur.
  
• Tiger conservation efforts are on in 28 national parks/sanctuaries. One such location is Bandipur. 
  
• Bandipur National Park is one of the best tiger reserves in the country and a prominent national park in Karnataka.
  
• So, the correct answer is option A.

• Keystone species are the critical species which have the large effect on the population of other species in the environment. 
• They are important to the community as they affect the species number and helps in maintaining the structure of the ecological community. 
• The population of other species depends on the population of keystone species e.g., figs acts as a keystone species, as it produces a large number of fruits and provides food for many animals. 
• So helps in increasing their survival rate. 

$$\textbf{Correct answer: D}$$ 

$$\textbf{Option (A):}$$ 

$$\bullet$$ Ecological diversity includes three different types of diversity.

$$\bullet$$ The species diversity is based on the number and the relative abundance of any species found in a particular region.

$$\textbf{Option (B):}$$ 

$$\bullet$$ Genetic diversity is the total number of genetic factors that are observed in the gene makeup of the given species.

$$\textbf{Option (C):}$$ 

$$\bullet$$ Ecosystem diversity refers to the variation in the different types of ecosystems and the organisms living in those ecosystems.

$$\textbf{Option (D):}$$ 

$$\bullet$$ Therefore, all three diversities are related to ecological diversity. 

Hence, the correct answer is option (D).