This set of Cytogenetics Multiple Choice Questions & Answers (MCQs) focuses on “Chromosomal Abnormalities : Euploidy”.
1. Euploidy is a chromosomal variation in ______________________
b) Position of genes
Explanation: Euploidy is chromosomal variation in number which shows increase or decrease in complete set of chromosome number.
2. Euploidy is a form of allopoliplody.
Explanation: In euploidy there is an increase in chromosomal set due to duplication of originally existing set and not due to blending of chromosomes of two organisms. Thus it is autoploidy and not Alloploidy.
3. A male ant is _______________
Explanation: Male ants, bees and wasps are produced by parthenogenesis, thus they have only one set of genes that was present in their mother- being monoploid.
4. A male bee can’t have a________________
c) Grand father
d) Grand mother
Explanation: A male bee is produced from the unfertilized eggs by parthenogenesis, thus it will have a mother but not a father. The female mother was produced by fertilization so there is a grandfather and grandmother.
5. Which of the following will be sterile?
Explanation: Tiploids are inherently sterile; this is due to the problem in meiosis that can produce a diploid and uniploid. The unpaired chromosome gets distributed in the two poles randomly leading to chromosomal inequality.
6. Colchicine is used to cause______________
a) Mitotic non-disjunction
b) Meiotic non-disjunction
c) Mitotic disjunction
d) Meiotic disjunction
Explanation: Colchinine causes an arrest in anaphase which leads to mitotic non-disjunction halting the mitosis. This leads to doubling of chromosome as the duplicated chromatins fail to separate.
7. In an experiment, you culture the anthers and leaves of a flower. You see the plants so generated are_____________
b) Monoploid and diploid
c) Diploid and triploid
Explanation: Anthers are the meiosis products, so the plant generated from it is monoploid. Leaf is a normal diploid somatic tissue which will give to diploid individual.
8. Choose the odd one out?
c) Fertilized egg
Explanation: Making a distinction on the basis of a number of sets of chromosome- endosperm is triploid while the rest are diploid.
9. Which of the following pairing will not occur during meiosis of tetraploid?
a) Two bivalent
b) One bivalent and two univalent
c) Trivalent and univalent
Explanation: In normal pairing all available chromosomes with complimentary are paired, so the existence of two univalent which are free to pair is not possible. However in case of trivalent and univalent as one of the other set is not available univalent exists.
10. Normal wheat Triticum aestivum is ___________
Explanation: Triticum aestivum is hexaploid i.e. there are 6 set of chromosomes in it. This fertile as the segregation in divalent is possible.
11. Farmers often practice polyploidy as ____________________
a) It makes the plants more durable
b) They take longer time to undergo meiosis
c) It increases complexity and there is a hope of new species
d) It produces larger plant parts and products
Explanation: In case of polyploid, more is the number of chromosome set more is the amount of gene product. As a result the plant will be larger is size which is a commercial profit.
12. In animals polypoidy is rarely practiced as _______________
a) Giants are harder to train and take care of
b) Increase in size is not appreciable
c) It is often sterile
d) Animal cells are resistant to colchicine
Explanation: The other options being true, in animals there is a more strict regulation of gene product formation than in the case of plants. In animals with an increase in cell size there would be a decrease in cell number keeping the ultimate animal sizes same. It is thus not profitable at all.
Sanfoundry Global Education & Learning Series – Cytogenetics.
To practice all areas of Cytogenetics, here is complete set of 1000+ Multiple Choice Questions and Answers.