The russian-american biochemist phoebus levene was the first to determine that nucleotides may contain one of four different nitrogen-containing bases. levene believed that the nitrogen-containing bases occurred in equal amounts in dna. what is the actual proportion of these bases?

It depends on the specimen

Step-by-step explanation:

The actual proportion of this bases depends a lot on the organism and the molecule, but it is mostly 60-40 and importance of it is that the purines need to be in equal amounts, and the pyramidines as well, so the proportion between purines and pyramidines is mostly 60-40%, but them between adenine and guanine the proportion is 30-30 and between cytosine and thymine should be 20-20.

walter needs to make at least 5 more cookies but no more than 40. 5 ≤ x ≤ 40

step-by-step explanation:

20 ≤ x + 15 ≤ 55

subtract 15 from all parts

20-15 ≤ x + 15-15 ≤ 55-15

5 ≤ x ≤ 40

this means how many more cookies he has to make

walter needs to make at least 5 more cookies, but no more than 40 cookies; 5 ≤ x ≤ 40

just take the area of the square and then the area of the circle then subtract the circle area from the squares area

step-by-step explanation: