1. when during the cell cycle is a cell’s dna replicated?
a) g1 phase
b) g2 phase
c) s phase
d) m phase

2. which of the following represents the phases of mitosis in their proper sequence? a) prophase, metaphase, anaphase, telophase
b) interphase, prophase, metaphase, anaphase, telophase
c) interphase, prophase, metaphase, telophase
d) prophase, anaphase, metaphase, telophase

The correct answers are-

1) C) S Phase

2) A) prophase, metaphase, anaphase, telophase.

Cell cycle corresponds to the division of cell, which occurs primarily through two phases that are - Interphase ( which has G1, S, and G2 phase) during which cell grows, duplicates its genetic material and M ( mitotic phase) phase during which cell divides.

S phase ( synthesis phase) corresponds to the duplication of the genetic material (DNA). It takes place place after G1 ( Gap 1 phase) phase.

2) Mitosis is a type of cell divison in which one parent cell divides to produce two daughter cells with same number of chromosomes. Prophase is the first phase, followed by metaphase, anpahse, and telophase.

1. I believe the correct answer is C. S Phase.

2. I believe the answer is B. interphase, prophase, metaphase, anaphase and telophase

The cell cycle is divided into 4 stages i.e. the Gap 1 (G1), Gap 2 (G2), Synthesis (S) and Mitosis (M) stage. The M stage is the longest and has 5 further stages that are interphase, prophase, metaphase, anaphase and then telophase. It is during the S phase that DNA is replicated

The cell cycle starts with the G1 stage where the cell rests from a previous cycle and also checks for any errors in the DNA. If none were found, it will proceed to the Synthesis (S) phase. In this phase, the chromosomes enter as single strands but come out as double strand due to replication of DNA. The cell cycle enters the G2 phase where for the last time error checking is done to confirm if any errors are present. If any are present, the cycle is terminated and if not, it proceeds to the Mitosis phase. In the M phase, the cell will undergo extensive cell division which starts with the chromatin condensing in the interphase and the nucleus envelope disappears releasing the chromosome pairs. Pairs of chromosomes then emerge in the prophase and food is stored for the division including doubling of cell organelles. Microtubules form in this stage. The cell then enters the metaphase stage where the chromosome pairs arrange themselves at the equator of the cell and held by the microtubules. The microtubules start to shorten and in the anaphase stage, single strands of chromosome are pulled to different poles of the cell and the microtubules then continue to shorten much more further pulling the single strands more towards the different poles. The cytoplasm then starts to pinch into 2 (cytokinesis) and the different sides start forming different nucleus. IN the end of telophase, 2 daughter cells emerge and the M phase ends concluding the cell cycle. The cell again will go into G1 phase to rest and start the next cycle.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."