Levels of biodiversity - class-X

Species diversity decreases as we move away from the equator towards the poles due to:-

Ecological diversity is the diversity at ecosystem level. India with its deserts, rainforests, mangroves, coral reefs, wetlands, estuaries and alpine meadows has a greater ecosystem diversity than a  Scandinavian country like Norway.

Although India has only 2.4 percent of the world's land area, its share of the global species diversity is an impressive 8.1 percent. 

The biodiversity shows a latitudinal and altitudinal gradient. The species diversity decrease as well as we move away from the equator towards the poles with very few exceptions, tropics harbour more species than temperature or polar areas.

Animals constitute more than 70% of all the species recorded whereas plants constitute around 22% of total number of species. 

Ecological diversity is of three types:
(i) Alpha diversity
(ii) Beta diversity
(iii) Gamma biodiversity.

Biodiversity changes with the change in altitude. It increases as one moves from higher to lower altitudes.

Ecological diversity is of three types:
(i) Alpha diversity
(ii) Beta diversity
(iii) Gamma biodiversity.

Species diversity is the number of different species present in a given population i. e. 'Species diversity relates to the number of different species.'
In population A, there are 3 different classes present. These are mammals, birds, and amphibians. Hence, it will have vast species diversity.
In population B, only 2 classes are present, namely mammals and amphibians. Hence, species diversity will be less compared to that of population A.
In population C, all the species belongs only to class mammals. Hence, it will show the least species diversity.

The relationshipbetween species richness and area is rectangular hyperbola for a wide variety of taxa whether they are birds, bats, freshwater fishes or flowering plants and the equation can be given as S = $CA^z$.

• Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species. For example, The genetic diversity shown by the medicinal plant Rauwolfia vomitoria growing in different Himalayan ranges might be in terms of the potency and concentration of the active chemical (reserpine) that the plant produces. 
• Genetic variation is an important force in evolution as it allows natural selection to increase or decrease the frequency of alleles already in the population.
  
• Stabilizing natural selection is most likely to decrease the genetic diversity in a population because the frequency of alleles remains constant in stabilized natural selection.
  
• So, the correct answer is 'Stabilising natural selection'.

The local species pool is known as alpha diversity. It is also the diversity present within the community. The term was introduced by R. H. Whittaker. Example of such diversity includes high tree diversity throughout the Amazon Rainforests of Ecuador. Generally, gamma diversity = alpha diversity x beta diversity.

In our biosphere immense diversity (or heterogeneity), exists not only at the species level but at all levels of biological organisation ranging from macromolecules within cells to biomes. Biodiversity is the term popularised by the sociobiologist Edward Wilson to describe the combined diversity at all the levels of biological organisation. The most important of them are- 
(i) Genetic diversity.
(ii) Species diversity.
(iii) Ecological diversity.

A great biodiversity exists on our planet. Millions of living plants and animal species are flourishing on Earth. An approximate of 1.7 million organisms are known to exist. New species are getting discovered and recorded every year.

Great biodiversity exists on our planet. Millions of living plants and animal species are flourishing on Earth. An approximate of 1.7 million organisms are known to exist. 61% of the total known species are of insects.

Great biodiversity exists on our planet. Millions of living plants and animal species are flourishing on Earth. An approximate of 1.7 million organisms are known to exist. Out of them, 309 mammal species are recorded in India.

India is one of the richest countries when it comes to the diversity of plant species. Around 45,000 plant species are estimated to be present in India. There are eight main florist regions in India which are Western Himalayas, Eastern Himalayas, Assam, Indus plain, Ganges plain, the Deccan, Malabar, and the Andaman Islands. So, great efforts for protecting the immense biodiversity should be done.

Species diversity decreases from equator to poles. The reason lies behind the fact that the conditions for the survival of species at poles become unfavorable. The Equator has favorable conditions for the survival of wildlife. Good vegetation, sunlight, and habitat these factors are responsible for great biodiversity at the equator.

Species diversity increases towards the equator. The two main reasons are phylogenetic niche conservatism and ecological productivity. The relatively high temperatures in the tropics generate and maintain high diversity. However, the tropical rainforests in developing countries are getting cleared nowadays, which is leading to a great loss of biodiversity.

Great biodiversity exists on our planet. Millions of living plants and animal species are flourishing on Earth. An approximate of 1.7 million organisms are known to exist. New species are getting discovered and recorded every year. Indian share in global species diversity is about 8%.

Species diversity is the number of different species that are represented in a given community. In India, rice has the largest species diversity or variety. India has 6,000 species variety of rice. The number has greatly reduced from before. The commonest rice is basmati rice.

Megadiversity refers to the diversity in various life forms. India is one of the megadiverse countries where diversity of global species is found. There are 4 biodiversity hotspots (the area where large species diversity is present) in India, they are:

The bottleneck effect occurs when a population's size is drastically reduced, leading to loss of genetic diversity as only certain individuals survive and reproduce. This reduces the gene pool. Mutation increases diversity, gene flow can increase diversity by introducing new alleles, and random mating maintains Hardy-Weinberg equilibrium.

Genetic diversity refers to the variety of genes within a species. Each species is made up of individuals, that have their own particular genetic composition. Within a species there may also be discrete populations with distinctive genes. 

Genetic diversity refers to the variety of genes within a species. Each species is made up of individuals that have their own particular genetic composition. Within a species there may also be discrete populations with distinctive genes. Sexual reproduction is critical for maintaining genetic diversity within a species, because it combines the parents genetic material, resulting in offspring with unique genetic blue prints different from either parent. 

Diversity in crops is showcased as genetic and phenotypic characters. These include variety of  the size of seeds, branching pattern, height differences, flower color, fruiting
time and flavor. Genetic diversity is the total number of genetic characteristics that make up the species and play a major role in modern plant breeding and the greatest diversity in crop plants is seen in the homelands.

Rice has more than 50,000 genetically different strains, while mango has 1000 varieties in India. 

The total variability of life forms on planet Earth is measured called as global biodiversity which is reported to be between 5 million and 30 million at present scenario.

Population is a unit of biotic community made of near group of multi breeding individuals of a species found in a geographical area at a particular time. It is called as deme.
Different populations of a species occupying different geographical areas are called as sister populations. 

The genetic diversity of a modern corn field is more diverse as it may contain genes transferred from from bacteria, to naturally protect it from pests 

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.

Species diversity is the variety in the number and richness of the species of a region. The number or species per unit area is called as species richness. Number of individuals of different species represent species evenness or species equitability. Communities where species are represented by more or less equal number of individuals exhibit evenness. Where one or more species have more individuals than other show dominance or unevenness. 

India is one of the twelve megadiversity regions of the world with 7.7 percent of genetic resources of the world. 

Species diversity is the diversity at the species level. For example, the western Ghats have a greater amphibian species diversity than the eastern Ghats. Although India has only 2.4 per cent of the world's land area, its share of the global species diversity is an impressive 8.1 per cent. That is what makes our country one of the 12 mega diversity countries of the world.

In our biosphere immense diversity (or heterogeneity) exists not only at the species level but at all levels of biological organisation ranging from macromolecules within cells to biomes. Biodiversity is the term popularised by the sociobiologist Edward Wilson to describe the combined diversity at all the levels of biological organisation. 

Genetic diversity is the diversity in the number and types of genes as well as chromosomes present in different species and variations in the gene and their alleles in the same species.
Population $\rightarrow $Species $\rightarrow $Chromosomes $\rightarrow $Genes $\rightarrow $Nucleotide is the correct sequence of genetic diversity.

Species diversity or genetic variation increases as one proceeds from high altitude to low altitude and high latitude to low latitude. Tropical rain forests are wet and dense. They exhibit maximum genetic variations due to increased temperature and rainfall.  They show high animal and plants biodiversity. 

Species diversity is defined as the number of different species in a given community. The species diversity in a community is maintained by predators. Predators are organisms that feed on prey. They can increase, decrease or leave unchanged species diversity. They increase species diversity by preying on competitive dominant species and reduce species diversity by reducing consumer pressure on foundation species.

• Species diversity increases as one proceeds from high altitude to low altitude and high latitude to low latitude. The temperature and seasonal variability increases with increased altitude and decreased latitude. Hence, this results in higher species diversity in these areas.

Gymnosperms mean naked seeds; their ovules are naked and freely exposed to pollination, and the fertilized seeds are not enclosed by carpels. Great biodiversity exists on our planet. Millions of living plants and animal species are flourishing on Earth. An approximate of 1.7 million organisms are known to exist. 64 gymnosperm species are known from India.

The variety and variability of living organisms (both plants and animals) are known as biodiversity. The variation measured by biodiversity is at the genetic, species, and ecosystem level. Gene-based diversity is known as genetic diversity. It is a way for populations to adapt to changing environments. A species spread over a large tract with varied environmental conditions will have higher genetic diversity.

Beta diversity is the diversity present between the communities. It is also the rate of replacement of species along a gradient of habitats/communities. Whereas, the local species pool is known as alpha diversity and the diversity present in the ranges of communities is known as Gamma diversity.

The relationship between the area of a habitat, or of part of a habitat, and the number of species found within that area is described by the species-area curve. It says that log S = log C + Z log A. Here S is the number of species, A is the habitat area, and Z is the slope of the species-area relationship. Larger areas tend to contain larger numbers of species.
So, the correct answer is 'log S = log C + Z log A'.

The local species pool is known as alpha diversity. It is also the diversity present within the community. The term was introduced by R. H. Whittaker. Example of such diversity includes high tree diversity throughout the Amazon Rainforests of Ecuador. Generally, gamma diversity = alpha diversity x beta diversity.

The number of taxa present within a particular area or an ecosystem is called alpha diversity. It is also the diversity present within the community. The term was introduced by R. H. Whittaker. Example of such diversity includes high tree diversity throughout the Amazon Rainforests of Ecuador. Generally, gamma diversity = alpha diversity x beta diversity.

India is considered a center of origin for many crops, and wheat shows significant genetic diversity in the region. While mango also has high diversity, wheat is a classic example in agricultural biology curricula.

A) The given region does not have much species richness. 

India is very rich in varieties of animals and plants species. Around 47,000 species of plants and twice the number of  animals have been recorded in India. Around 81,000 species of animals have been recorded in India. Hence, the ratio of animals and plants species in India is 2:1.

Statement A is incorrect as species diversity decreases and not increases as we move away from the equator towards the poles temperature decreases and conditions becomes harsh, vegetation decreases and less resources available to support species. 

In biology, a deme is a term for a local population of organisms of one species, that actively interbreed with one another and share a distinct gene pool. When demes are isolated for a very long time they can become distinct subspecies or species. The term 'deme' is mainly used in evolutionary biology and is often used as a synonym for population. In evolutionary computation a "deme" often refers to any isolated subpopulation subjected to selection as a unit rather than as individuals. 

Alpha diversity : species diversity within a community or habitat, comprises two components, i.e., species richness and evenness. Sometimes dominant of one vegetation stratum may affect the diversity of the other strata. 

The flora of India is one of the richest of the world due to a wide range of climate, topology and environments in the country. It is thought there are over 17,500 species of flowering plants in India. India covers more than 45,000 species of flora, out of which there are several species that are not found anywhere else. Since ancient times, use of plants as a source of medicines has been the inherent part of life in India. There are more than 3000 officially documented plants in India that holds great medicinal potential. India comprises seven percent of world's flora.

Sexual reproduction is critical for maintaining genetic diversity within a species because it combines the parents genetic material, resulting in offspring with unique genetic blueprints different from either parent. Genetic diversity is important for two reasons. First of all, when a population of an organism contains a large gene poolthat is, if the genetic blueprints of individuals in the population vary significantly the group has a greater chance of surviving and flourishing than a population with limited genetic variability. Second, genetic diversity also reduces the incidence of unfavorable inherited traits. The home lands of our food crops are vital geographic regions where the greatest genetic diversity for each species can be found. Because in homelands there are more chances of sexual reproduction with in the species which is critical for maintaining genetic diversity. Thus, option B is correct. Greatest genetic diversity of plants is not found in Central America, India and South America. Thus, other options are wrong.

Statement (a) is correct as both are consumers. Statement (b) is correct as Pisaster is a well-known keystone predator that maintains diversity. Statement (c) is incorrect because predators rarely drive prey to extinction, and (d) is incorrect because these chemicals are secondary metabolites, not disorders.

Species diversity is the number of different species, that are represented in a given community. 

A) Species 2000 is an autonomous federation of taxonomic database custodians which involves taxonomists in the whole world. 

It is given that out of blue, red, green and black variations of insects, only red and green insects established a new population on the new island. Since, these four colors are controlled by two genes, new population could have either of colour of insects. It is an example of founder effect. The island population will have lower genetic diversity than the mainland population because small populations usually have less genetic diversity than large population.