It is spring and a little boy has terrible allergies. His nose is stuffed with mucus and he has a cough. Why are his mucous membranes producing so much mucus? He is allergic to mucus.
It is a sign that he has a head injury.
Mucus traps pollen so it cannot enter the body.
Mucous membranes always make more mucus in spring.

the correct answer, according to e2020, is the second choice there is an occluded front in region a and a cold front in region b.

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.

label a cell membrane

label b cytoplasm

label c ribosomes

label d dna

the membrane forms the outside of the cell

cytoplasm is the liquid within

ribosomes are the components within that distribute rna

the dna is the genetic make-up