5.1. Replication and division of nuclei and cells
A subsection of Biology, 9700, through 5. The mitotic cell cycle
Listing 10 of 204 questions
Describe the process of DNA replication. State the name of the part of the chromosome that prevents the loss of genes during DNA replication. During DNA replication, the use of an incorrect base in the newly synthesised strand can lead to a mutation. A transversion event is where a pyrimidine is used in the newly synthesised strand instead of a purine, or the other way round. Name the two possible bases that could be used instead of cytosine in a transversion event. A transition event is where an incorrect purine is used or an incorrect pyrimidine is used. Suggest why transversion events are less likely to occur than transition events. Outline how mutations can cause healthy cells to become tumour cells.
9700_s17_qp_23
THEORY
2017
Paper 2, Variant 3
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Stem cells are found throughout the human body. Lgr5+ stem cells are found in the lining of the small intestine. is a flow chart showing stages in the development of one of the daughter cells produced by the mitotic division of an Lgr5+ stem cell. specialised cells from the epithelium lining the small intestine X Y Explain why stem cells are required in places such as the lining of the small intestine. Name the stage of mitosis shown in cell X in . State the part of the cell cycle shown at Y in . Explain the role of centromeres in the cell cycle. shows three types of specialised cell that develop from Lgr5+ stem cells in the small intestine. P Q R The structural features of a cell indicate its likely function. Suggest a function of each of the cells shown in , and explain how the structure of each cell supports your suggestion. cell P function explanation cell Q function explanation cell R function explanation
9700_w24_qp_23
THEORY
2024
Paper 2, Variant 3
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Questions Discovered
204