The term you're referring to which scientists implement to describe "different forms of life on Earth" is perhaps "Organism".
"Kidneys are often compared to filters because they cleanse unwanted waste from both frogs and humans" is TRUE.
Answer: Option A
<u>Explanation:
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Frogs also have the excretory system with two kidneys and similar to mammals. Its function is to eliminate the nitrogen product from the blood. Frogs make large volumes of dilute urine to wipe out harmful products from the tubules of the kidneys.
Tadpoles and aquatic frogs excrete the nitrogen as ammonia, but most terrestrial adults excrete it mostly as urea which is less threatening substance. A few tree frog species with little water access excrete the still less harmful uric acid.
The seasons are caused as the Earth, tilted on its axis, travels in a loop around the Sun each year. Summer happens in the hemisphere tilted towards the Sun, and winter happens in the hemisphere tilted away from the Sun. As the Earth travels around the Sun, the hemisphere that is tilted towards or away from the Sun changes.
Let us look at the what, why and how of studying extreme places like the deep earth and the deep space. Scientists need to figure out as to 'what' they want to look at such places, be it a new exotic creature or bio-genesis (birth of life). Unless there are several testable hypothesis constructed, such a study cannot begin. The 'why' aspect deals with the purpose of such research and expeditions. Is it of any use to the humans, or will it improve our current understanding of a phenomenon? The 'how' aspect deals with the technology and the economic assistance that can help in undertaking such a research. All these are the challenges that needed to be thoroughly considered to make such a research or expedition possible.
