Answer:
The main function of the RB protein is to inhibit the transition from the G1 to S phase. Its activity depends on its phosphorylation state: if RB is not phosphorylated (active state), it is bound to the transcription factor E2F, preventing its translocation to the nucleus and the activation of genes necessary for DNA synthesis; and if it is phosphorylated, by cyclin-CDK complexes, E2F is released and cell proliferation occurs.
Explanation:
Retinoblastoma (Rb) was the first tumor suppressor described and, as we know today, mutations in its structure determine a large number of cancers. Structurally, we speak of a large and multifunctional protein; which is organized in different domains. The activity of this protein is regulated, mainly, by phosphorylation at multiple sites described over the years and is involved in control mechanisms of the cell cycle, apoptosis and senescence.
Bottleneck is an example of a genetic drift that happens when the size of a population is severely reduced.
Answer:
sigma subunit
Explanation:
Sigma subunit of RNA polymerase holoenzyme directs the enzyme towards the consensus sequences present upstream of the transcription start site. Completion of the initiation phase of transcription is followed by dissociation of sigma subunit from the transcription complex.
The protein NusA replaces the sigma subunit. The RNA polymerase leaves the promoter and starts the elongation
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Answer:
It can lead to melanoma or a time of skin cancer.
Explanation:
This is because UV radiation in sunlight can destroy the DNA by destroying the base pairing. UV light will cause two Thymine that are very closer to each other to join together to produce dimer. After which, The melanin-assisted process form lesions that is popularly called cylobutane pyrimidine dimers in DNA, which can result in mutations that cause melanoma which is a form of skin cancer
