Environment & Biodiversity MCQs

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The researchers at the University of St Andrews in Scotland have found that gray seals can copy the sounds of human words and songs including “Twinkle, Twinkle, Little Star”. The study showed that 3 trained seals were able to imitate parts of popular tunes. The study gave the researchers a better understanding of the evolution of vocal learning and human language development. It also suggested that gray seals could be a new model to study speech disorders since they use their vocal tracts the same way as humans. The grey seal is found on both shores of the North Atlantic Ocean. It is a large seal of the family Phocidae which are commonly referred to as “true seals” or “earless seals”. It is the only species classified in the genus Halichoerus.

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Water pollution in river or any other water body is measured by amount of dissolved oxygen. Water pollution can be measured on the basis of parameters like dirtyness, change in texture, total suspended solid and other important factors like,
1. Decrease in dissolved oxygen (DO) (concentration of dissolved oxygen in water samples).
2. Increase in BOD, (Biochemical Oxygen Demand) it is a chemical procedure for determining the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period.
3. Increase in COD, (Chemical Oxygen Demand) test is commonly used to indirectly measure the amount of organic compounds in water.
 

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Contaminated water is treated with chlorine which removes suspended solid particles in water, remove the hardness of water and kill germs.

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Montreux Record is a register of those Ramsar wetland sites where ecological changes have or are taking plac eleading to their depletion and thus the site requires conservation. From India Keoladeo national Park of Rajasthan and the Loktak lake of Manipur are under the list.

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Alpha (α) diversity is a measure of biodiversity within a particular ecosystem or habitat, which entails detailed cataloging of the variety of coexisting species. An instance would be noting the diversity of fish, marine invertebrate, algae, and other constituent species on a single coral reef. Integral to ecological studies, it helps to understand the richness and organization of biological entities within a specific localized environment and has critical implications for conservation strategies. The term Alpha originated from a convention in ecological studies and is partnered with Beta and Gamma diversities, indicative of other diversity levels.

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The internal environment of a fish is relatively stable as compared to the external environment. However the environment is not always constant. Injury, illness or excessive stress can upset the internal environment of a fish.

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Population is a group of organisms which are usually of the same species, occupying a defined area during a specific time. Birth and immigration lead to increase in population. Death and emigration lead to decrease in population.

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The pyramid of numbers deals with the relationship between the numbers of primary producers and consumers of different levels in an ecosystem. Pyramid of numbers is not always be upright, and can even be completely inverted.

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In an upright pyramid of numbers the number of individuals decrease from lower level to higher trophic level. Grassland ecosystem is an example of an upright pyramid of numbers.

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In brackish water ecosystems the water bodies have salt content in between 5 to 35 ppt. Some of the examples of brackish water ecosystems are estuaries, salt marshes, mangrove swamps and forests.