CELL STRUCTURES AND FUNCTION
CELL CYCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Mitosis
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Synthesis
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Gap 1
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Gap 2
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Detailed explanation-1: -Following a low dose of UV radiation, DNA replication is inhibited and the cells undergo a transient arrest re-entering the cell cycle by 24 h. Instead, a high dose of UV damage leads to an initial replicative arrest followed by death of the cells by apoptosis.
Detailed explanation-2: -UV irradiation alters the expression of multiple genes that encode functions to repair DNA damage, arrest cell growth, and induce apoptosis. In addition, UV irradiation inhibits protein synthesis, although the mechanism is not known.
Detailed explanation-3: -Ultraviolet (UV) light induces specific mutations in the cellular and skin genome such as UV-signature and triplet mutations, the mechanism of which has been thought to involve translesion DNA synthesis (TLS) over UV-induced DNA base damage.
Detailed explanation-4: -It has been reported that UV-C exposure can delay mitotic progression through an alternative mechanism to DNA damage response29. The induction of many mitotic genes following UV exposure may result in the delay of mitotic progression via activation of the SAC.