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Question 01

In a double stranded molecule of DNA, the ratio of purines : pyrimidines is:

a) variable

b) determined by the base sequence in RNA

c) genetically determined

d) always 1:1

e) determined by the number of purines in the sense strand of the DNA

Question 02

Which of the following nucleotide bases is not found in RNA?

a) thymine

b) adenine

c) uracil

d) guanine

e) cytosine

Question 03

Which of the following molecules does not form part of DNA?

a) purine

b) pyrimidine

c) deoxyribose

d) amino acid

e) phosphate

Question 04

The transcription of DNA to a molecule of messenger RNA occurs:

a) on the ribosomes

b) in the cytosol

c) in the nucleus

d) only during cell division

e) when amino acids are made available by transfer RNA

Question 05

The process of translation requires the presence of:

a) mRNA, tRNA and ribosomes

b) mRNA, ribosomes and RNA polymerase

c) DNA, mRNA and RNA polymerase

d) chromatin, DNA and amino acids

e) free nucleotide bases, amino acids and ribosomes

Question 06

Codons are composed of:

a) triplet sequences of nucleotide bases in mRNA

b) triplet sequences of nucleotide bases in DNA

c) triplet sequences of amino acids in polypeptide chains

d) triplet sequences of deoxyribose sugars in DNA

e) none of the above

Question 07

The mode of action of a steroid hormone involves:

a) binding to a cell membrane recactivation of protein kinaseseptor

b) activation of protein kinases

c) binding to calmodulincovalent modification of enzyme activity

d) covalent modification of enzyme activity

e) modifying gene transcription

Question 08

Mutations are errors in DNA that:

a) are always harmful

b) only occur in the presence of carcinogens

c) increase tumour growth

d) occur spontaneously at a low rate

e) only occur on the X chromosome

Question 09

The sex of a child is dictated by the inheritance of:

a) the number of X chromosomes from the mother

b) a recessive allele on the X chromosome

c) a single Y chromosoa single Y chromosome from the fatherme from the mother

d) a single Y chromosome from the father

e) Y chromosomes from the mother and father

Oxford University Press, Online Resource Centre, Chapter 07.

Chapter 07

Instructions