AP BIOLOGY

Detailed explanation-1: -Solutions for A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. The amount of DNA (in picograms) found at the end of S and G2 phase would be Correct answer is ‘16’.

Detailed explanation-2: -Answer and Explanation: DNA is doubled during S phase. That would give us 16 picograms. At the end of G2 we will still have double the amount (16 picograms) because the cell does not divide and restore the original amount of DNA until after G2.

Detailed explanation-3: -In the third step of mitosis, called metaphase, each chromosome lines up in a single file line at the center of the cell. By this point in time, the membrane enclosing the nucleus has dissolved, and mitotic spindles have attached themselves to each chromatid in all the chromosomes.

Detailed explanation-4: -Metaphase: During metaphase, each of the 46 chromosomes line up along the center of the cell at the metaphase plate.

Detailed explanation-5: -The cell undergoes two divisions in meiosis i.e. meiosis I and meiosis II. Meiosis I is reduction division and meiosis II is similar to mitosis but DNA replicates only once during meiosis, i.e. before meiosis I in S phase.