7. If you have a 100-base pair DNA molecule that contains 45 cytosines, how many adenines are there?

5 adenines

Explanation:

Cytosine pairs with Guanine, and Adenine pairs with Thymine. This means, that if there are 45 cytosines, there must be 45 guanines. So that's 90 base pairs down. That means that there are 10 left between adenine and thymine- so that means there are 5 adenines

more words for this could be abiotic and biotic

abiotic: living organisms within an ecosystem

biotic: non-living organisms within an ecosystem

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.