Question

1. If the S phase of interphase occurred but G1 and G2 did not, would the cell still undergo cell division?A)Even though G1 and G2 phases did not occur and therefore protein synthesis did not occur in interphase, the cell would still divide. The enzymes, proteins and chemical messengers will be made in prophase to conduct the cell division process B)No, the cell would not divide since G1 and G2 did not occur and therefore the proteins, enzymes and chemical messengers needed to conduct the process of cell division would not have been synthesized. C) Yes, the cell would still divide since the S phase occurred making enough chromosomes for the new cells to be produced.

Answer 1

Answer)

The eukaryotic cell cycle is regulated by two proteins cyclins and CDKs(cyclin-dependent kinases).CDK production remains constant throughout the cell cycle. Whereas different cyclins are produced at different stages of the cell cycle.

Example: Cyclin e and A are produced in G1/S phase,

Together with cycling, Cdks regulate the activation of next phase proteins production.

For example :

G1/S phase cyclins activate the transcription factors and S phase cyclins that are required for the S phase.

S/G2 phase cyclins activate the transcription factors and Cyclins that promote transcription of genes that are required in the M phase.

Failure in doing so, the checkpoint regulation does not allow the cell to enter the next phase of the cell cycle.

In the above case, although the S phase has happened successfully, G2 did not occur.

Without G2 there won't be any activation of gene transcriptions and protein production that are required in the M phase.

Therefore the cell will no divide due to lack of proteins that are required for the M phase of the cell cycle.

Option C is the right answer.