During an interphase lasting 23 hours the s stage takes average 8.0 hours. what is the percentage of interphase is taken up by s stage?

The right answer is 34.78%

The interphase is the period of the cell cycle that the cell transcribes its genes and the chromosomes are duplicated. It can be subdivided into several phases:

* phase G1

* phase S: during which the chromosomal material is doubled by DNA replication. This is called chromosome duplication.

* phase G2.

Phase G1 is the longest phase of the interphase (its duration depends on the type of cell), followed by phase S, then phase G2.

To calculate the proportion of phase S in the interphase simply make the division:

phase duration S / interphase duration = 8/23 = 0.3478 (in percentage that is 34.78% (0.3478*100)).

prophase: we can observe the chromosomes to coil up and condense. they become visible. nuclear membrane and envelope disintigrate.s

metaphase: chromosomes align at the center, the metaphase plate. spindle fibers attach to centromeres of the sister chromatids. they meet at kinetochores.

anaphase: sister chromatids are pulled towards each opposing centromere, set on different poles.

telophase: chromosomes are now clustered up only on either sides of the cell. nuclear membranes reform, and a new cell wall forms along the cell plate. this will lead to cytokinesis, the process that divides the cell membrane and forms the cell wall.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.