AP BIOLOGY

Detailed explanation-1: -They isolate a group of cells that have 1 1/2 times more DNA than G1 phase cells. What is the most likely part of the cell cycle from which these cells were isolated? between the G1 and S phases in the cell cycle.

Detailed explanation-2: -A cell cycle is a series of events that takes place in a cell as it grows and divides. A cell spends most of its time in what is called interphase, and during this time it grows, replicates its chromosomes, and prepares for cell division. The cell then leaves interphase, undergoes mitosis, and completes its division.

Detailed explanation-3: -In G1, cells accomplish most of their growth; they get bigger in size and make proteins and organelles needed for normal functions of DNA synthesis. Here, proteins and RNAs are synthesized, and, more especially the centromere and the other components of the centrosomes are made.

Detailed explanation-4: -During S phase, which follows G1 phase, all of the chromosomes are replicated. Following replication, each chromosome now consists of two sister chromatids (see figure below). Thus, the amount of DNA in the cell has effectively doubled, even though the ploidy, or chromosome count, of the cell remains at 2n.

Detailed explanation-5: -Answer and Explanation: The answer is true, G1 phase cells contains half as much DNA as G2 phase cells. This because during the time between these two gap periods, the S phase occurs. In the S phase, the DNA in the cell is completely replicated.