When the body breaks down proteins (polymers of amino acids), whether because of famine or because there are too many amino acids in the body, the amino group containing nitrogen must be removed and discarded. This is discarded from a mammal's body in the form of .

Urea

When the body breaks down proteins (polymers of amino acids), whether because of famine or because there are too many amino acids in the body, the amino group containing nitrogen must be removed and discarded. This is discarded from a mammal's body in the form of urea.

Explanation:

In mammals such as humans, amino nitrogen is excreted as urea. Hence, mammals are referred to as ureotelic animals.

Unlike mammals, amino nitrogen is excreted as ammonia in aquatic animals while as uric acid in reptiles and birds.

not sure if this is what you'r looking for eubacteria and archaebacteria

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.