ecology & bio environment geography section 1 MCQ Questions & Answers Detailed Explanation

Answer: (c)

Green accounting is a type of accounting that attempts to factor environmental costs into the financial results of operations.

It has been argued that gross domestic product ignores the environment and therefore decision-makers need a revised model that incorporates green accounting.

Answer: (c)

A food chain is a linear sequence of links in a food web starting from a trophic species that eats no other species in the web and ends at a trophic species that is eaten by no other species in the web.

A food chain differs from a food web because the complex polyphagous network of feeding relations are aggregated into trophic species and the chain only follows linear monophagous pathways. A common metric used to quantify food web trophic structure is food chain length. In its simplest form, the length of a chain is the number of links between a trophic consumer and the base of the web and the mean chain length of an entire web is the arithmetic average of the lengths of all chains in a food web.

Food chains were first introduced by the African-Arab scientist and philosopher Al-Jahiz in the 9th century and later popularized in a book published in 1927 by Charles Elton, which also introduced the food web concept.

Answer: (d)

Sanitary landfills are low lying sites where waste is isolated from the environment until it is safe. It is considered when it has completely degraded biologically, chemically and physically. In high-income countries, the level of isolation achieved may be high.

Answer: (c)

There are different types of interactions in the biotic community. Frog feeds for snakes. Snakes are the main predators of frogs.

The control over a prey is determined by the level of competition faced by other predators. If the same prey is prey to other predators, the control is considered to be lesser.

Answer: (d)

Forests are considered as sinks of carbon dioxide. A carbon sink is anything that absorbs more carbon that it releases, whilst a carbon source is anything that releases more carbon than is absorb. It is for this reason that they are indispensable in the present global scenario marked by increasing global warming and climate change.

Answer: (a)

Productivity is the rate of organic matter or biomass production. The average ocean productivity is about 50 grams of carbon per square meter per year; while, the average land productivity is 160 grams of carbon per square meter per year.

Salt marshes and mangroves have one of the highest productivity of 3300-6000 grams of carbon per square meter per year.

So the correct sequence of the ecosystem in the order of decreasing productivity is:

Mangroves > Grasslands > Lakes > Oceans.