which nucleotide is in rna but not in dna?

a.

thymine

b.

adenine

c.

cystosine

d.

guanine

e.

uracil

What does it mean for a cell membrane to be selectively permable

You arrive late to a biological seminar. however, just as you enter the room, you hear the speaker referring to the "five-prime end" and the "three-prime end" of a macromolecule. immediately, you know that they are talking about a: ]

When does the circulatory system work with the respiratory system? a. during blood cell formation b. during cellular respiration c. during intestinal digestion d. during a viral infection