This set of Life Sciences Multiple Choice Questions & Answers (MCQs) focuses on “Cell Division”.
1. Name the type of cell division in which daughter cells receive an exact copy of chromosomes from parent cell?
Explanation: Basically eukaryotes have two types of cell division, mitosis, and meiosis. Meiosis is reductional division while mitosis is equational division and the number of chromosomes in parent and daughter cells remain same.
2. Who coined the term mitosis?
a) Robert Hook
b) Walther Flemming
c) Farmer and Moore
d) F. Twort
Explanation: Walther Flemming in 1882 introduced the term mitosis. It is the process where one round of DNA replication is trailed by a single round of chromosomal segregation. It generates two genetically identical cells.
3. Which of the following is a microtubule organizing center?
c) G2 phase
Explanation: Microtubule organizing center (MTOC) is centrosome, present outside the nuclear membrane. It regulates the cycle of cell division as well as microtubule formation.
4. Among the following, which one is not the substage of mitosis?
Explanation: Mitosis starts with the nuclear division called karyokinesis followed by cytokinesis. This phase is further divided into four substages: prophase, metaphase, anaphase, and telophase.
5. Name the protein which holds two sister chromatids?
Explanation: SMC (Structural Maintenance of Chromosome) protein cohesin hold together the sister chromatids at centromere while separase is ubiquitous cysteine protease which degrades cohesin during anaphase.
6. Which of the following microtubule pulls the chromosomes towards pole?
Explanation: Kinetochore microtubule is a mitotic spindle which attaches to chromosome at the specific site called kinetochores. It pulls the two sister chromatids at the opposite pole during anaphase.
7. Plant cells have centrosomes and astral microtubule at their spindle poles.
Explanation: Plant cells do not have centrosomes and astral microtubule at their poles. In plant cells, mitotic spindle formed from MTOC originate from nuclear envelop itself.
8. Spindle fiber attached to the chromosome by a process known as_________
d) Search and capture
Explanation: Search and capture is a process by which plus end of microtubule search the kinetochore site at the chromosome and attach to it. These microtubules radiate from the MTOC of the poles.
9. What is congression?
a) Attachment of microtubule to chromosomes
b) Attachment of two sister chromatids
c) The endpoint of the spindle pole
d) The midpoint of two spindle poles
Explanation: The arrangement of chromosomes at the center of the poles or at the metaphase plate, which is a midpoint and this midpoint is called congression.
10. In which of the following phase, sister chromatids move towards opposite poles?
Explanation: The sister chromatids are attached to the kinetochore tubule at the metaphase state and start moving towards the opposite poles at anaphase stage. At anaphase, the sister chromatids split apart and move to opposite poles of the spindle.
11. Which of these proteins is responsible for depolymerization of microtubule?
a) Kin I kinesin
Explanation: CENP-E, Kin I kinesin, and dynein are the motor proteins which contain kinetochores. Out of them only Kin I kinesis is responsible for depolymerization of microtubule from its plus end while dynein generates poleward forces toward its minus end.
12. Name the medication which hinders the shortening of the microtubule.
Explanation: All of these drugs affect the process of cell division at different stages like colchicine inhibits microtubule formation, cytochalasin inhibits cytokinesis, and taxol prevents the shortening of microtubules.
Sanfoundry Global Education & Learning Series – Life Sciences.
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