Genetics Multiple Choice Questions and Answers

11. Which of the following factors could lead to variations in the offspring of asexually reproducing organisms?

1. Crossing over.
2. Fertilization.
3. Mutations.
4. Independent assortment.

12. The enzyme which builds a mRNA strand complimentary to the DNA transcription unit is called:

1. DNA polymerase
2. RNA polymerase
3. Helicase
4. DNA ligase

13. Changes in the nucleotide sequence of DNA which arent passed to offspring occur in

1. Eggs & sperm cells
2. Non-sexual cells
3. Diploid and haploid cells
4. All of the above

14. A gene is a section of DNA that codes for a protein, this unique sequence of bases will code for the production of a unique protein is:

1. Exon
2. Intron
3. Regulatory sequence
4. None of these

15. The triplet code of CAT in DNA is represented as ______ in mRNA and ______ in tRNA.

1. GAA, CAT
2. CAT, CAT
3. GUA, CAU
4. GTA, CAU

16. ______ portions of chromosomes that stain lightly andonly partially condensed

1. Heterochromatin
2. Euchromatin
3. Facultative chromatin
4. Constitutive

17. Those mutations that arise in the absence of known mutagen are known

1. Induced mutations
2. Fused mutations
3. Spontaneous mutations
4. None of the above

18. Chromosomes measurements are generally taken during

1. Interphase
2. Prophase
3. Anaphase
4. None of these

19. Which of the following is correct with regard to aneuploidy?

1. Inversion
2. 2n + 1
3. All aneuploid individuals die before birth
4. 4n

20. The X - ray diffraction studies conducted by ______ were key to the discovery of the structure of DNA

1. McClintock
2. Franklin
3. Meselson and Stahl
4. Chargaff