Environmental Studies · Biology

Ecology and Biodiversity

1,737 Questions

Ecology and biodiversity are vital topics in environmental studies, covering ecosystem structures, species diversity, and environmental impacts. These concepts are frequently tested in competitive examinations for civil services and state selections. The questions cover carrying capacity, ecological succession, and conservation fundamentals.

Species richness measurementTypes of ecological diversityBiome distribution factorsCarrying capacity conceptEcosystem servicesEnvironmental Impact Assessment

Ecology and Biodiversity Questions

Multiple choice

Biological communities change because

  1. new species move in, displacing the old ones

  2. the soil is depleted and all the food gets finished

  3. old species evolve into new species

  4. each stage modifies the environment and adapts for a later stage
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Biological communities change because each stage modifies the environment and adapts for a later stage. This change is due to growing acceptance for the idea that all of life is interconnected and that the living world is tied to the non-living or inorganic world. 

Multiple choice

Biodiverstiy forms the basis for human existence in the following ways:

  1. Soil formation
  2. Prevention of soil erosion
  3. Recycling of waste
  4. Pollination of crops

Select the correct answer using thew codes given below:

  1. 1, 2 and 3 only

  2. 2, 3 and 4 only

  3. 1 and 4 only

  4. 1, 2, 3 and 4
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Significance of diverse biodiversity:  Reducing soil erosion, preventing flooding, maintain purity of water, tempering climate fluctuation, increasing productivity of soil, recycling of waste, soil formation, pollination of crops, etc.

Multiple choice

Consider the following statements:

  1. Biodivesity is normally greater in the lower latitudes as compared to the higher latitudes.
  2. Along the mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes.

Which of the statements given above is/are correct?

  1. 1 only

  2. 2 only

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The increase in species richness or biodiversity that occurs from the poles to the tropics, often referred to as the latitudinal gradient in species diversity (LDG), is one of the most widely recognized patterns in ecology.  Species diversity varies systematically across the globe with latitude, longitude, and altitude (or its equivalent, depth, in the oceans). The trend toward higher species diversity in the tropics is perhaps the most conspicuous biogeographic pattern in nature. In most marine groups, diversity is maximal in the Indo-West Pacific.  Many mountain ecosystems are host to higher species richness and levels of endemism than adjacent lowlands. Mountains at lower altitudes can support exceptional biodiversity, due to compression of a wide range of ecosystems into a relatively short distance. Mountains also often provide islands of suitable habitat, isolated from unfavourable surrounding lowlands.

Multiple choice

Which of the following does not characterise an ecosystem?

  1. During stress conditions, the count of rare species gets reduced in an ecosystem.

  2. An ecosystem is considered to be unstable if its structure and functions remain more or less the same throughout the year.

  3. An ecosystem having high population diversity and low dominance is regarded as less productive in nature.

  4. In ecosystems, the biotic communities generally accomodate large number of individual species occurring in small numbers.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is just the reverse statement as an ecosystem is considered to be stable in the ecological sense if its structure and functions remain more or less the same throughout the year.

Multiple choice

Pyramid of biomass in a pond ecosystem is always

  1. upright

  2. inverted

  3. linear

  4. dumbbell shaped
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pyramid of biomass - Amount of living or organic matter present in an organism is called biomass. Pyramid of biomass is upright for terrestrial habitats; inverted or spindle-shaped in aquatic habitats.

Multiple choice

Which of the following provides the best estimate of world’s biological diversity?

  1. Of about ten million species probably alive today, some 20 species are lost everyday, most of them unknown because no more than half a million have been actually identified.

  2. Of about thirty million living species, some 50 are lost everyday, most of them unknown because no more than one million have been actually identified.

  3. Of about forty five million living species, some 100 are lost everyday, most of them unknown because no more than 1.5 million have been actually identified.

  4. Of about seventy five million living species, some 500 are lost everyday, most of them unknown because no more than 3 million have been actually identified.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Of about ten million species probably alive today, some 20 species are lost everyday, most of them unknown because no more than half a million have been actually identified. This statement provides the best estimate of world’s biological diversity among the options provided.

Multiple choice

During ecological succession:

  1. the gradual and predictable change in species composition occurs in a given area

  2. the establishment of a new biotic community is very fast in its primary phase.

  3. the numbers and types of animals remain constant.

  4. the changes lead to a community that is in near equilibrium with the environment and is called pioneer community
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

 (a)

Multiple choice

Among the following types of ecosystems, the annual average of net plant production is highest in

  1. temperate grassland

  2. savannah

  3. shrublands

  4. temperate forest

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Net primary productivity (NPP) is highest in ecosystems with abundant water and warm temperatures throughout the year, which allows for year-round photosynthesis. Temperate forests, especially those with high rainfall, generally exhibit higher annual NPP than grasslands or savannahs.

Multiple choice

Which of the following statements are INCORRECT on ecological point of view? P. Primary succession involving xerosere is initiated in a wet habitat. Q. Halones commonly found in electronic equipment are one of the active force destroying the protective ozone layer in the stratosphere. R. Sympatric speciation occurs when the new species evolves in geographic isolation from the parent species. S. $\alpha$-Diversity is the diversity of species within a habitat or community.

  1. P, Q

  2. P, R

  3. Q, R

  4. Q, S
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Statement P is incorrect because primary succession via a xerosere starts in an extremely dry habitat, not a wet one. Statement R is incorrect because sympatric speciation occurs without geographic isolation, whereas allopatric speciation involves geographic isolation. Statements Q and S are correct descriptions of halons and alpha-diversity.