Correct Answer – Option 2 – Temperature and amount of available water

Abiotic components are the nonliving components of an ecosystem. Chemical and geological factors, such as rocks and minerals, physical factors such as temperature and weather are referred to as abiotic factors.

Biodiversity is not a nonliving factor hence option 1 is incorrect.

Producers and decomposers in a forest ecosystem are living organisms. Hence, option 3 is incorrect.

Heterotrophs are living or biotic components of the forest ecosystem. Hence, option 4 is incorrect

Correct Answer – Option 3 – Organisms in this food web are interdependent.

Only when organisms in a food web are interdependent the population, growth, or any character influencing one set of organisms will affect the other organisms which are interdependent.

In a food web both producers and consumers are important. Hence, option 1 is incorrect.

Both producers and consumers are needed to support the food web. Hence, option 2 is incorrect.

Due to various environmental, biotic and abiotic factors populations in a food web cannot be constant. Hence, Option 4 is incorrect.

Correct Answer – Option 1 – Human actions are a threat to equilibrium in ecosystems.

The diagram above represents modifications of ecosystem by humans through the use of technology, consumption and population growth disrupting the equilibrium in ecosystems.

Hence, the options 2,3 and 4 are incorrect.

Correct Answer – Option 3 – industrialization has increased the amount of carbon dioxide in the air

Increase in carbon dioxide leads to the green house effect leading to the overall increase in temperature at Earth’s surface.

Destruction of decomposers does not cause an increase in temperature. Hence, option 1 is incorrect.

Trees consume carbon dioxide to release oxygen. Hence, deforestation will lead to an increase in the level of oxygen. So, option 2 is incorrect.

Plants – crops again consume carbon dioxide to generate oxygen. And oxygen in the atmosphere does not lead to depletion of ozone layer. Hence, option 4 is incorrect.

Correct Answer – Option 2 – environmental carrying capacity

Decreasing completion may lead to an increase in frog population. Hence, option 1 is incorrect.

Excessive dissolved oxygen will help in the growth of water borne plants, providing more food for frogs.

This should lead to an increase in frog population. Hence, option 3 is incorrect.

The depth of water is not related to the population of the frogs. Hence, option 4 is incorrect.

Hence, the only reason why the frog population in a pond remains constant would be the carrying capacity of the environment. Hence, option 2 is the correct answer.

Correct Answer – Option 1 – The ecosystem will change until a new stable community is established

The tsunami affected the marine ecosystem hence, leading to change. This change will be in process until a new stable community will be established.

However, there is no assurance of continuation or extinction of ecological succession neither the extinction of organisms. Hence, options 2,3 and 4 are incorrect.

Correct Answer – Option 2 – recycling of nutrients

The mulching lawn movers cuts the grass clippings into very fine pieces and deposit them into soil do ensure decomposition and formation of nutrients to be utilized by the grass for growth. Hence, the recycling of nutrients takes place.

However this process does not ensure increasing the diversity of life, or control of pathogens or the production of new species. Hence, options 1,3 and 4 are incorrect.

Correct Answer – Option 4 – the loss of biodiversity

Deforestation of areas considered to be rich sources of genetic material cannot improve the quality of atmosphere, or cannot lead to maintenance of dynamic equilibrium nor lead to an increase in the rate of evolutionary change. Hence, options 1, 2 and 3 are incorrect.

Deforestation will definitely lead to loss of biodiversity. Hence, option 4 is the most apt answer.

Correct Answer – Option 1 – An increasing food supply from day 5 to day 6

According to the graph, the predator population is not equal in size to the prey population from day 5 to day 6. Hence, option 2 is incorrect.

The decrease in prey population is from day 0 to day 2 and again from day 6 to day 10. Hence, option 3 is not the most relevant interpretation of the graph.

Yeast does not become extinct on day 3. Hence, option 4 is incorrect.

Hence, option 1 is the correct interpretation of the graph.

Correct Answer – Option 4 – a population at equilibrium

The graph in the portion labeled A is representing constant population following a sinusoidal curve providing the inference that the population is in equilibrium. Hence, option 1 is correct.

The graph has no information about biodiversity or nutritional relationship of the fish population. Hence, the interpretations in options 1 and 2 are incorrect.

At no point other than the start the graph becomes 0. Hence, the interpretation that the portion of the graph labeled A represents a population becoming extinct is incorrect.