PAL S5 Expressions DB014

Our genome operates by sending info from ....... in the nucleus, via ......, to guide the synthesis of ..... at ribosomes in the cytoplasm.

• proteins, mRNA, DNA

• DNA, proteins, mRNA

• DNA, mRNA, proteins

• mRNA, proteins, DNA

In an analysis of the DNA nucleotide composition to see which bases are equivalent in concentration, which of the following would be true?

• A = C

• A = G and C = T

• A + C = G + T

• A + T = G + C

Which of the following models of replication represents DNA replication?

• semi-conservative

• conservative

• dispersive

• uniform replication

What is meant by the phrase " the genetic code is degenerate"?

• some codons specify stop and start signals, rather than amino acids.

• some codons specify more than one amino acid

• certain amino acids can be specified by more than one codon

• all organisms have essentially the same genetic code.

Which of the following statements explain transcription process?

• it produces amino acids

• it produces messenger RNA

• it is semi-conservative process

• it causes addition in DNA synthesis

Insulin is a protein that consists of 51 amino acids, and only involves 17 from 20 types of amino acids normally used in protein synthesis. What is the minimum number of different tRNA molecules in insulin synthesis?

• 3

• 17

• 21

• 51

What is the role of helicase in DNA replication?

• stabilising the double helix

• unwind the double helix

• form the new preliminary DNA structure

• form the Okazaki fragments

The following events occur in the replication of DNA.

1. bonds between complementary bases break.

2. bonds between complementary bases form.

3. DNA molecule uncoils.

4. opposite strands separate.

5. sugar-phosphate bonds form.

6. free nucleotides align with complementary nucleotides on each strand.

• 1, 3, 6, 4, 2, 5

• 3, 1, 4, 6, 2, 5

• 3, 6, 1, 4, 5, 2

• 4, 3, 1, 6, 5, 2

Which of the following statements is true about translation during protein synthesis?

• The enzyme aminoacyl-tRNA synthetase activates an amino acid.

• DNA has the codons and binds to the ribosome.

• DNA polymerase is involved in the synthesis of mRNA.

• The initiation of protein synthesis begins with codon UAA on the mRNA.

If a DNA template with the sequence of 5'-TCGATGTA-3' is transcribed, what would be the sequence of the corresponding mRNA?

• 5'-AGCUACAU-3'

• 5'-UACAUCGA-3'

• 5'-ACGTACAT-3'

• 5'-TACATCGA-3'