Question

1. the s phase stands for synthesis, which means to make or build something more complex out of simpler parts. scientists know that during the s phase dna is being made in the nucleus of the cell. why do you think the cell needs to make more dna at this time in the cell cycle? 11. refer to model 1. the chromosomes that are shaped like “x” (made of two sister chromatids) have double the amount of dna than the chromosomes that are shaped like “i”. during what phase of the cell cycle do you think the chromosomes are replicated (copied)?

Explanation:

1. The S - phase stands for synthesis. During the S - phase of the cell cycle, DNA replication occurs. The cell needs to make more DNA because it is preparing for cell division. Each new cell will need a complete set of genetic information.
2. Chromosomes are replicated during the S - phase of the cell cycle. After replication, each chromosome consists of two sister chromatids. The amount of DNA doubles because each original DNA molecule serves as a template for a new complementary strand.

Answer:

1. The S - phase stands for synthesis. The cell needs to make more DNA at this time in the cell cycle because it is preparing for cell division and each new cell must have a full set of genetic material.
2. Chromosomes are replicated during the S - phase of the cell cycle. After replication, they have double the amount of DNA as they consist of two sister chromatids (copied DNA).