Introduction and Biodiversity Questions in English

(B) The species-area relationship was proposed by the German naturalist and geographer $Alexander \text{ } von \text{ } Humboldt$.
While exploring the wilderness of South American jungles, he observed that within a region, species richness increased with increasing explored area, but only up to a limit.
The relationship is described by the equation: $log S = log C + Z log A$, where $S$ is species richness, $A$ is area, $Z$ is the slope of the line (regression coefficient), and $C$ is the $Y$-intercept.

(D) The term $Biodiversity$ was popularized by the sociobiologist $Edward \ O. \ Wilson$ to describe the combined diversity at all the levels of biological organization.

(D) According to the data provided in the $NCERT$ textbook regarding biodiversity in the Amazonian rain forest,the species richness is as follows:
$1$. Plants: $40,000$ species
$2$. Fishes: $3,000$ species
$3$. Birds: $1,300$ species
$4$. Mammals: $427$ species
$5$. Amphibians: $427$ species
$6$. Reptiles: $378$ species
Therefore,there are $427$ species of amphibians present in the Amazonian rain forest.

(C) $IUCN$ stands for International Union for Conservation of Nature.
It is an international organization working in the field of nature conservation and sustainable use of natural resources.
It is well known for publishing the $IUCN$ Red List of Threatened Species,which assesses the conservation status of species worldwide.

(C) According to the $IUCN$ Red List $(2004)$,more than $15,500$ species worldwide are facing the threat of extinction.
This includes $784$ species that have become extinct in the last $500$ years,including $338$ vertebrates,$359$ invertebrates,and $87$ plants.

(B) The Western Ghats are known for their high level of biodiversity and are considered a biodiversity hotspot. Specifically,they exhibit a significantly higher species diversity of amphibians compared to the Eastern Ghats. This is due to the unique climatic conditions,high rainfall,and varied topography of the Western Ghats,which provide diverse niches for amphibian species.

(D) According to the $NCERT$ textbook for Class $12$ Biology,Chapter $15$ (Biodiversity and Conservation),it is estimated that more than $25,000$ species of plants contribute to the traditional medicines used by native peoples around the world.

(D) $X$: India has $2.4\%$ of the world's land area,not $4.1\%$. Thus,statement $X$ is False.
$Y$: Biodiversity is not uniform across the globe; it varies significantly due to factors like climate,altitude,and geography,showing an uneven distribution. Thus,statement $Y$ is True.
$Z$: Alexander von Humboldt observed that within a region,species richness increased with increasing explored area,but only up to a limit. This is known as the species-area relationship. Thus,statement $Z$ is True.
Therefore,the correct sequence is False,True,True.

(A) According to the biodiversity data for the Amazon rainforest provided in the $NCERT$ textbook:
$1$. Mammals $(a)$ = $427$ species $(d)$
$2$. Birds $(e)$ = $1300$ species $(b)$
$3$. Fishes $(f)$ = $3000$ species $(c)$
Therefore,the correct matching is $a-d, b-e, c-f$.

(A) The Aravalli Range is a mountain range in Northern-Western India,running approximately $692 \ km$ in a south-westerly direction,starting near Delhi,passing through Southern Haryana and Rajasthan,and ending in Gujarat. The majority of the range lies within the state of Rajasthan.

(C) India has a rich diversity of rice. There are more than $50,000$ genetically different strains of rice in India. This high level of genetic diversity is a significant aspect of India's biodiversity,which helps in the development of various high-yielding and disease-resistant varieties.

(D) The species-area relationship is given by the equation $S = CA^Z$.
Taking the logarithm on both sides,we get $\log S = \log C + Z \log A$.
In this linear equation,$S$ represents species richness,$A$ represents the area,$C$ is the $Y$-intercept,and $Z$ represents the regression coefficient,which is the slope of the line.

(B) According to the $NCERT$ textbook on Biodiversity and Conservation:
$1$. There are more than $20,000$ species of ants.
$2$. There are $3,00,000$ species of beetles.
$3$. There are $28,000$ species of fishes.
$4$. There are nearly $20,000$ species of orchids.
$5$. India has more than $50,000$ genetically different strains of rice and $1,000$ varieties of mango.
Therefore,option $B$ is the correct statement.

(B) According to the data provided in the $NCERT$ textbook regarding the biodiversity of the Amazonian rain forest:
$1$. Plants: More than $40,000$ species.
$2$. Fishes: $3,000$ species.
$3$. Birds: $1,300$ species.
$4$. Amphibians: $427$ species.
$5$. Mammals: $427$ species.
$6$. Reptiles: $378$ species.
Comparing these with the given options,the pair 'Birds - $378$ species' is incorrect because the actual number of bird species in the Amazonian rain forest is $1,300$,while $378$ is the number of reptile species.

(A) According to the global biodiversity data provided in the $NCERT$ textbook,animals account for more than $70\%$ of all the species recorded.
This means that out of every $10$ animals on this planet,$7$ are insects.
Plants (including algae,fungi,bryophytes,gymnosperms,and angiosperms) comprise no more than $22\%$ of the total species recorded.
Therefore,both statement $A$ and statement $R$ are correct.

(A) According to the data on global biodiversity,insects represent the most species-rich taxonomic group on Earth.
It is estimated that for every $10$ animals on this planet,$7$ are insects.
This is because insects account for more than $70\%$ of the total animal species identified so far.
Therefore,the correct answer is $7$.

(D) The $Western \text{ } Ghats$ are recognized as one of the world's biodiversity hotspots.
They exhibit a very high level of species richness and endemism due to their unique geographical location, high rainfall, and diverse climatic conditions.
In India, the $Western \text{ } Ghats$ and the $Himalayas$ are the primary regions known for exceptionally high biodiversity compared to other areas.

(A) The Amazon rain forest is often referred to as the 'lungs of the planet'.
It is estimated that the Amazon rain forest produces approximately $20\%$ of the total oxygen in the Earth's atmosphere through the process of photosynthesis.
Therefore,the correct option is $A$.

(A) Forests are essential for the survival of life on Earth. According to global estimates,approximately $1.6$ billion people,including more than $2,000$ indigenous cultures,depend on forests for their livelihood. This includes reliance on forest products for food,shelter,medicine,and income.

(B) The term $Biodiversity$ refers to the variety and variability of life on Earth. It encompasses the diversity of organisms in terms of their size,shape,habitat,lifestyle,and genetic makeup. Since the question describes the wide range of differences observed in living organisms,the correct term is $Biodiversity$.

(C) Tropical rain forests are characterized by high rainfall and high temperature throughout the year.
In India,these forests are primarily located in the Western Ghats (including Kerala) and the North-Eastern regions (including Assam).
Therefore,the correct option is $C$.

(B) species that is found exclusively in a particular geographical region and nowhere else in the world is known as an $Endemic$ $species$.
$Sibling$ $species$ are morphologically similar but reproductively isolated.
$Sympatric$ $species$ are those that live in the same area but are reproductively isolated.
$Allopatric$ $species$ are those that inhabit different geographical areas.

(D) Tropical rainforests,such as the Amazon,are known for having the highest biodiversity and species density on Earth. This is due to the stable,warm climate and abundant rainfall throughout the year,which supports a vast array of flora and fauna.

(C) Species diversity is determined by the number of species present in a given area (species richness).
$1$. Area $A$: Species present are $a, b, c, d, f, g, h, j$. Total = $8$ species.
$2$. Area $B$: Species present are $a, c, e, f, h, i, j$. Total = $7$ species.
$3$. Area $C$: Species present are $a, b, c, d, e, f, g, h, i, j$. Total = $10$ species.
$4$. Area $D$: Species present are $a, b, c, d, e, f, g, h, i, j$. Total = $10$ species.
Comparing the species richness, both $C$ and $D$ have $10$ species. However, in ecological studies, if the number of species is equal, we look at the evenness or the total population distribution. In this specific dataset, $D$ shows a more balanced distribution across all $10$ species compared to $C$, which has some very low values (e.g., $0.48$). Thus, $D$ is considered to have higher diversity.

(A) The total freshwater on Earth is distributed in various forms. Approximately $70\%$ of the world's total freshwater is trapped in the form of polar ice and glaciers. This water is not readily available for human consumption as it is frozen in the ice caps of Antarctica,Greenland,and mountain glaciers.

(A) The $Indri$ $indri$,also known as the babakoto,is the largest living lemur species. It is endemic to the island of Madagascar,specifically found in the eastern rainforests of the island. Lemurs are primates that are found exclusively in Madagascar.

(C) biodiversity hotspot is a biogeographic region with a significant reservoir of biodiversity that is under threat from destruction. The criteria for identifying a hotspot,as defined by Norman Myers,include:
$1$. It must contain at least $1,500$ species of vascular plants as endemics (High degree of endemism).
$2$. It must have lost at least $70\%$ of its original habitat (High rate of species loss/threat).
'Low interspecific competition' is not a criterion for identifying a biodiversity hotspot. High species richness is also a characteristic feature of these regions.

(B) In India,there are more than $50,000$ genetically different strains of rice and $1,000$ varieties of mango. However,rice exhibits the highest genetic diversity among the options provided. Genetic diversity refers to the diversity in the number and types of genes as well as chromosomes present in different species or the variation in genes within a single species. Rice ($Oryza$ $sativa$) has a vast number of varieties adapted to different agro-climatic regions in India.

(C) Statement $C$ is correct because the Western Ghats are recognized as one of the world's biodiversity hotspots,characterized by high levels of species richness and a significant number of endemic species (species found nowhere else).
Statement $A$ is incorrect because desert regions generally have lower species richness compared to tropical or temperate regions.
Statement $B$ is incorrect because the large-scale cultivation of $Bt$ cotton can potentially impact non-target organisms and overall agro-biodiversity.
Statement $D$ is incorrect because biodiversity conservation is a global responsibility,essential for the survival of all nations,regardless of their economic status.

(D) Biodiversity hotspots are regions with high levels of species richness and a high degree of endemism that are under threat.
In India,there are four recognized biodiversity hotspots:
$1$. The Himalayas
$2$. The Western Ghats
$3$. The Indo-Burma region
$4$. The Sundaland (which includes the Nicobar Islands).
Therefore,among the given options,the Western Ghats is a recognized biodiversity hotspot.

(D) Species that are confined to a specific geographic region and are not found naturally anywhere else in the world are known as $Endemic$ species. For example,many species found in the Western Ghats or on islands are endemic to those regions.

(A) Norman Myers originally identified $25$ biodiversity hotspots globally. Later,the number was increased to $34$ by Conservation International. Currently,there are $36$ recognized biodiversity hotspots in the world. Given the options provided,$34$ is the most historically significant answer associated with the expansion of the list.

(C) Genetic diversity refers to the variation of genes within a species. It allows a population to adapt to its environment and ensures survival. In the case of mangoes $(Mangifera \text{ } indica)$, the existence of over $1,000$ varieties in India, which differ in flavour, colour, fibre content, sugar content, and shelf-life, is a classic example of genetic diversity at the intraspecific level.

(C) India is known for its immense agricultural biodiversity.
It is estimated that there are approximately $200,000$ varieties of rice in India alone.
This diversity is a significant part of the country's rich biological heritage and is crucial for food security and breeding programs.

(A) Within biological communities,some species are crucial in determining the ability of a large number of other species to persist in the community. These species are known as $keystone$ species.
$Allopatric$ species are those that occupy mutually exclusive geographic areas.
$Sympatric$ species are those that inhabit the same or overlapping geographic areas.
$Threatened$ species are those likely to become endangered in the near future.

(C) Tropical rain forests have a high density of organisms.
Tropical rain forests are mainly found in Central America,South America,the Congo River basin of Africa,and South East Asia.
In this biome,rainfall and warmth are abundant,leading to luxuriant plant growth.
This biome possesses more than half of the world's flora and fauna.
Productivity is very high,and the diversity of life is so immense that a single hectare of forest may contain $200$ species of trees.
Approximately $70-80\%$ of all insects and $80-85\%$ of all birds are known to inhabit tropical rain forests.

(B) Ecological diversity is categorized into three types: $\alpha$, $\beta$, and $\gamma$ diversity.
$\alpha$-diversity refers to the diversity within a single community or habitat.
$\beta$-diversity refers to the diversity that exists between communities or habitats, often representing the change in species composition along an environmental gradient.
$\gamma$-diversity refers to the total diversity of a landscape or geographic region.
Therefore, $\beta$-diversity is the diversity between communities.

(C) The Eastern Himalayas and the Western Ghats are recognized as two of the most significant biodiversity hotspots in India.
Biodiversity hotspots are regions that harbor a high level of species richness and a high degree of endemism,meaning many species found there are not found anywhere else on Earth.
The Eastern Himalayas are home to a vast array of flora and fauna,including $163$ globally threatened species such as the Asian elephant $(Elephas \text{ } maximus)$,the greater one-horned rhinoceros $(Rhinoceros \text{ } unicornis)$,and the tiger $(Panthera \text{ } tigris)$.
The Western Ghats are also globally renowned for their exceptional biodiversity,containing a large number of endemic plant and animal species.
Therefore,these two regions are considered to have the maximum biodiversity in our country.

(D) Biodiversity hot spots are regions that are exceptionally rich in biodiversity and are under significant threat due to human activities.
In India,there are three recognized biodiversity hot spots: the Western Ghats and Sri Lanka,the Himalayas,and the Indo-Burma region.
Among the given options,the Western Ghats are a globally recognized biodiversity hot spot characterized by high levels of endemism and habitat loss due to developmental activities.

(C) The Assertion is correct. Gamma diversity refers to the total species diversity in a landscape or a large geographical area,which includes the diversity of different habitats within that region.
The Reason is incorrect. Biodiversity generally increases from high altitude to low altitude (or from poles to the equator) because lower altitudes (or tropical regions) provide more stable,favorable,and resource-rich environments for a wider variety of species.
Therefore,the Assertion is correct but the Reason is incorrect.

(A) Species that are restricted to a specific geographic area and are not found anywhere else in the world are known as $Endemic$ species.
Western Ghats are a well-known biodiversity hotspot in India,characterized by a high degree of endemism,meaning many of its flora and fauna are unique to that region.
$Vulnerable$ and $Threatened$ refer to the conservation status of species based on their risk of extinction.
$Keystone$ species are those that have a disproportionately large effect on their environment relative to their abundance.

(D) Bioprospecting is the systematic search for new sources of chemical compounds,genes,microorganisms,macroorganisms,and other valuable products from nature.
It involves the exploration of molecular,genetic,and species-level diversity to identify biological resources that have potential economic or commercial value.
Biopiracy,on the other hand,refers to the unauthorized exploitation of biological resources and traditional knowledge by commercial organizations.
Bioenergetics is the study of energy flow through living systems,and bioremediation is the use of organisms to remove pollutants from the environment.

(N/A) This should be called 'biodiversity'.
Biodiversity is the term used to describe the combined diversity of all living organisms (plants,animals,and microorganisms) present in a specific habitat or on Earth.
Since the habitat contains both plant species and animal species,the term 'biodiversity' is appropriate as it encompasses the variety of life forms present in that ecosystem.

(N/A) Biodiversity refers to the variety and variability of life on Earth. It is typically measured by three hierarchical levels of biological organization:
$1$. Genetic diversity: It refers to the diversity in the number and types of genes as well as chromosomes present in different species and the variations in the genes and their alleles in the same species.
$2$. Species diversity: It refers to the variety of species within a region. The number of species per unit area is called species richness.
$3$. Ecosystem diversity: It refers to the diversity at the level of the ecosystem,such as the variety of habitats,biotic communities,and ecological processes in the biosphere.

(N/A) The biodiversity on our Earth is both astonishing and mesmerizing.
There are $20,000$ species of ants,$3,00,000$ species of beetles,$28,000$ species of fishes,and nearly $20,000$ species of orchids found on Earth.
Ecologists and evolutionary biologists are trying to understand the significance of this diversity through various questions,such as: $(i)$ Why are there so many species? $(ii)$ Did this diversity evolve throughout Earth's history? $(iii)$ How is it important for the biosphere? $(iv)$ What would be the effect on ecosystem functioning if this diversity were less? Most importantly,how can humans benefit from this diversity?

(N/A)

Species Diversity	Ecosystem Diversity
It refers to the variety and abundance of species within a specific region or community.	It refers to the variety of habitats,biotic communities,and ecological processes in the biosphere.
It focuses on the number of different species and their relative abundance in a given area.	It focuses on the diversity of ecosystems such as deserts,rainforests,mangroves,coral reefs,etc.,in a geographical region.
Example: The number of different species of birds or trees in a forest.	Example: The presence of diverse ecosystems like alpine meadows,wetlands,and estuaries in a country like India.

(N/A) $(i)$ Genetic diversity: It refers to the diversity in the number and types of genes as well as chromosomes present in different species and the variations in the genes and their alleles in the same species. It enables a population to adapt to its environment.
$(ii)$ Hotspot: These are regions with very high levels of species richness and high degree of endemism (species confined to that region and not found anywhere else). These areas are also under constant threat of habitat loss.

(N/A) $(i)$ In-situ conservation: This is the process of protecting an animal or plant species in its natural habitat,either by protecting or cleaning up the ecosystem itself,or by defending the species from predators.
$(ii)$ Biodiversity: Biodiversity refers to the variety of life forms,including microorganisms,plants,and animals,found in a particular area or ecosystem,reflecting the health and stability of that environment.