Answer: Option B. -> Biomagnification
:
B
Biological magnification or biomagnification is the accumulation of non-biodegradable substances in the food chain. It is found in all types of ecosystems. It leads to higher toxicity in organisms occupying higher trophic levels. E.g., successive increase in the concentration of a pesticide, DDT in an aquatic food chain.

Answer: Option C. -> Changes in packaging.
:
C

Improvements in our lifestyle have resulted in greater amounts of waste material generation. Changes in attitude also have a role to play, with more and more things we use becoming disposable.
Changes in packaging have resulted in much of our waste becoming non-biodegradable. Non-biodegradable wastes are materials that will not be decomposed by natural processes. Non-biodegradable waste products have long-lasting effects on land fills, where toxic pollutants often contaminate ground water. Non-biodegradable plastics can also lead to out-gassing.

Answer: Option A. -> True
:
A
Biodegradation is a chemical process in which materials are decomposed by bacteria or other biological elements. If a material is biodegradable, it means that it can be consumed by microorganisms and can be turned into compounds that are natural. It is an important process in ecology and waste management.

Answer: Option B. -> Grass, Goat and Human
:
B
Food chain is a series of organisms feeding on one another. From the given options, 'grass, goat and human' forms a food chain. Here, grass prepares its food during photosynthesis and becomes food for a goat, which in turn becomes food for humans. This food chain starts with producers (i.e.,grass) and ends in tertiary consumer (i.e. human). 

Answer: Option C. -> Secondary consumer
:
C
A simple food chain starts with autotrophs. They are eaten by primary consumers (herbivores). Primary consumers are then eaten by secondary consumers, which are then eaten by tertiary consumers. Thus, tertiary consumers occupy the top level in the food chain.
In the given example, grasshopper is the primary consumer. Mouse occupies the trophic level of secondary consumers, while owl is the tertiary consumer. 

Answer: Option A. -> True
:
A
Solar energy is captured by autotrophs i.e. green plants. They are then eaten by herbivores and herbivores in turn by carnivores. The energy flows from autotrophs to carnivores. Energy never reverts to the lower trophic levels. Thus, the energy flow is unidirectional.

Answer: Option A. -> producers
:
A
Autotrophs are also known as producers. They occupy the first trophic level. They convert the solar energy into chemical energy making it available for the successive trophic levels.