Food webs are limited to 5-6 levels because .
A. More levels would lead to a level of complexity that could not be sustained in a natural ecosystem
B. Energy is lost with each trophic level, and at some point there isnât enough energy to sustain one more trophic level
C. Higher trophic levels require more energy for their metabolism because they are larger
D. If there are too many levels in the food web, it is possible for the animals lower on the chain to be consumed completely
E. Because there is only a possibility of 5 levels: primary producers, primary consumers, secondary consumers, tertiary consumer and higher level consumer

economic impact of malaria is estimated to cost africa $12 billion every year. this figure factors in costs of health care, absenteeism, days lost in education, decreased productivity due to brain damage from cerebral malaria, and loss of investment and tourism.

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.

radon is correct hope this