Gamma rays are the most harmful of the given options as they can penetrate the skin and damage our cells.
Answer:
All animals alike as heterotrophs beacuse animals cannot prepare their own food.
Explanation:
Heterotrophs may be defined as the organisms that will depend upon plants or other animals for their food. They are unable to synthesize their own food.
All animals are heterotrophs as they depends on the other organisms for the production of food. All animals are also referred as consumers.
B. Natural selection
Natural selection can be
defined as the basic mechanisms of which goes along with migration, mutation
and genetic drift. Also, it is process in which an organism get adapted to its
environment by means of selectively reproducing changes in its genetic constitution.
Surface water (rivers and lakes) are the most available source of fresh water. The other sources of fresh water are largely unavailable.
Water on earth could be fresh water or salt water. The difference between the two is that freshwater is not salty. There is a limited quantity of available freshwater on earth.
Fresh water is found in glaciers, surface lakes and rivers and groundwater.The order of decreasing availability of fresh water on earth is ice> Groundwater > lakes and rivers (surface water).
Unfortunately, the source of freshwater that can easily be obtained for human use is surface water (lakes and rivers). There is only about % available freshwater in rivers and lakes. About 87% of the world's fresh water supply is locked away in glaciers.
Given the limited availability of fresh water sources, the possibility of an water challenges in the world can not be over emphasized. Definitely, there may not be enough water in the future hence water conservation efforts must be taken seriously.
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