Genetics MCQ Quiz - Multiple Choice Questions & Answers Page 3

21. 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

22. 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

23. 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

24. 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

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

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

26. 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

27. Chromosomes measurements are generally taken during

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

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

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

29. 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

30. Carriers of the colour-blindness trait include:

1. Men who are heterozygous for the trait.
2. Men who are homozygous for the trait.
3. Women who are heterozygous for the trait.
4. Women who are homozygous for the trait.