This set of Cell Biology Multiple Choice Questions & Answers (MCQs) focuses on “Cellular Reproduction – M-Phase”.
1. The term mitosis was coined in ____________
Explanation: The term mitosis was coined in the year 1882 by German biologist Walther Flemming. The word originates from greek word “mitos” meaning thread. It is an important part in the life cycle of a cell.
2. Mitosis is the process of segregation of DNA molecules into 2 cells.
Explanation: Mitosis is the process of nuclear division in which the replicated DNA molecules are segregated into two nuclei. The nuclei then end up in two originating daughter cells.
3. Cytokinesis is the process of division of two daughter cells by the partitioning of _________________
c) Messenger RNA
Explanation: After the process of mitosis, the following process is that of cytokinesis. It is the division of a cell into two by partitioning of the cytoplasm of the cell. The two daughter cells resemble each other and also the parent cell.
4. During mitosis, the cell becomes less responsive to external stimuli.
Explanation: During mitosis, the cell expends all of its energy only on chromosome segregation. During this phase all other activities of the cell are suppressed and it does not respond to external stimuli as well.
5. How many phases of mitosis are there?
Explanation: Mitosis has five phases – prophase, prometaphase, metaphase, anaphase and telophase; that constitute different segments of a continuous process that mitosis is. The morphology of chromosomes changes during these phases.
6. Cytoskeleton is disassembled in which of the following phase?
Explanation: The cytoskeleton is disassembled in the prophase of mitosis, and mitotic spindle is assembled following condensation of chromosomal material to form compact chromatids.
7. Centromeres split during the __________________
Explanation: Centromeres are the junction where two sister chromatids are joined. In the anaphase of mitosis, the centromeres split and chromatids separate and the chromosomes move to opposite poles.
8. Which is the last phase in mitosis just before the beginning of cytokinesis?
Explanation: The last phase in mitosis, just before the onset of cytokinesis is the telophase. During this phase chromosomes cluster at opposite spindle poles and the daughter cells form by cytokinesis.
9. Condensin is a ___________________
a) multiprotein complex
c) membrane phospholipid
d) transcription inhibitor
Explanation: Condensin is a multiprotein complex believed to play a major role in chromosome compaction. The proteins of condensing were discovered by incubating nuclei in frog egg extracts.
10. Chromosome compaction at prophase requires ______________________
a) DNA helicase
b) DNA polymerase
c) RNA polymerase
d) Topoisomerase II
Explanation: Chromosome compaction at prophase requires topoisomerase II which is present as a part of mitotic chromosome scaffold along with the multiprotein complex condensing.
11. When was the mechanism behind cytokinesis first discovered?
Explanation: In 1950s, the proposal made by Douglas Marsland known as the contractile ring theory is responsible for the current understanding of mechanism behind cytokinesis. He proposed that the force required to cleave the cell resides in the cortex, just beneath the furrow of dividing cell.
12. “Cell plate” is a term relative to cytokinesis in ______________________
Explanation: Cell plate is a simple precursor, the construction of which initiates the formation of a new cell. Plant cells are enclosed by inextensible cell walls and therefore undergo cytokinesis by a different mechanism.
Sanfoundry Global Education & Learning Series – Cell Biology.
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