Genetics : Cell Division
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Example Questions
Example Question #31 : Cell Division
Mutations in genes encoding cell cycle regulatory components may contribute to all of the following except __________?
proto oncogene
cancer
loss of cycle control
genomic instability
proto oncogene
Mutations can lead to lack of regulation, which overall, leads to genomic instability providing opportunities for uncontrolled growth — for example, cancer from the loss of cell cycle control. Proto oncogenes are normal genes that promote and regulate cell growth. Mutations to the proto oncogene itself could lead to oncogenes, which are cancer promoting.
Example Question #32 : Cell Division
A __________ is a normal gene that promotes regulated cell growth and proliferation, while a __________ is a mutated or over expressed gene that promotes cancer.
carcinogen, mutagen
mutagen, carcinogen
proto oncogene, oncogene
oncogene, proto oncogene
proto oncogene, oncogene
Proto oncogenes promote proteins via proliferation with regulation. Oncogenes promote cell proliferation without regulation, leading to genomic instability, which can lead to cancer. A mutagen is a physical or chemical substance that can increase the frequency of mutations. A carcinogen is a substance that is directly involved in causing cancer.
Example Question #33 : Cell Division
p53 is a famous __________, which aids in blocking cell cycle progression and preventing cancer.
proto oncogene
tumor suppressor
checkpoint
oncogene
tumor suppressor
p53 is a famous tumor suppressor, which blocks cell cycle progression preventing damaged/mutated DNA from being duplicated. Proto oncogenes are normal genes that regulate cell growth and proliferation. Oncogenes are mutated proto oncogenes that lead to unregulated cell proliferation. The checkpoints are in the S, G1, G2/M phases.
Example Question #34 : Cell Division
Which of the following describes a centromere?
the fiber spindle connecting individual chromosomes during mitosis
the center of a daughter cell after mitosis
the last stage of cell division
the center of an individual chromosome
the fiber spindle connecting individual chromosomes during mitosis
The correct answer here is the fiber connecting the chromosomes in the initial stages of mitosis. Remember that during mitosis, 1 pair of chromosomes becomes 2 new pairs. This requires the pair to split initially, duplicate, then break off into the new cells. The last stage of cell division is called anaphase, not a centromere. A centromere is the middle of a pair of chromosomes, not the individual chromosome. If you chose the daughter cell, remember that centromeres are not describing the new cell itself, but the connection between chromosomes inside the cell.
Example Question #35 : Cell Division
How are gametes produced?
meisosis
mitosis
RNA replication
crossing over
meisosis
The correct answer here is meiosis. Some of the options look challenging because you could assume RNA or DNA replication would result in gametes. However, the term gamete singularly refers to a sex-germ cell that is the direct result of meiosis. We can cancel out mitosis because that is specifically to replicate non sex related cells.
Example Question #36 : Cell Division
What best describes spindle fibers?
act as the primer in RNA creation
only present during mieosis, not mitosis
the fibers that help move/rearrange chromosomes during the later stages of mitosis
connect individual chromosomes to make a pair
the fibers that help move/rearrange chromosomes during the later stages of mitosis
The correct answer is that they are the fibers that help move the chromosomes towards a certain side of the cell during mitosis. If you chose the option about connecting a pair of chromosomes, remember that this is called a centromere and is also vital in mitosis. If you chose that the spindle fibers are only necessary in meiosis, remember that even in mitosis, fibers are needed to separate the individual chromosomes to form a new cell. Fibers do not act as the primer in RNA production
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