Key Question Answers From Exam Workbook

Question 1

How is DNA stored in a nucleus

Answer 1

Wound around Histone

Tightly coiled into chromosomes

Question 2

Eukaryotic DNA

Answer 2

Not associated with proteins

Condensed by supercoiling

Question 3

Complete set of proteins from a cell

Answer 3

Proteome

Question 4

Prokaryotic DNA

Answer 4

No introns no non coding sequences

Shorter fewer repeat sequences between genes

Question 5

Key words

Answer 5

Ribosomal RNA
Catalysing
Proteome
Complimentary base pairing
Adjacent tRNAs
Peptide bond formation
ATP
Amino acid chain is extended
Stop signal
Codon
RNA polymerase DNA helicase
Template strand
Exons 
Introns
CDNA

Question 6

Mitochondria DNA

Answer 6

Mitochondria DNA is shorter, circular, and is not associated with proteins.

Question 7

Degenerate

Answer 7

Means multiple DNA codons can code for one amino acid.

Question 8

Translation

Answer 8

The mRNA attaches to a ribosome.

TRNA molecules carry amino acid to the ribosome.

The TRNA is attached to the mRNA via complimentary base pairing.

The amino acid is on adjacent TRNA are joined together with peptide bonds.

ATP provides the energy for peptide bond formation.

The ribosome moves along the mRNA and the amino acid chain is extended.

The process continues until a stop signal on the mRNA is reached.

Question 9

Translation

Answer 9

After the DNA has been unwound by DNA helicase.

RNA polymerase lines up free RNA nucleotides along the template strand.

According to the rules of complimentary base pairing.

RNA polymerase then joins the RNA nucleotides together as it moves along the DNA template strand.

Once RNA polymerase reaches a stop signal, it detaches and the mRNA is released.

Question 10

CDNA

Answer 10

CDNA only contains exons

This is because cDNA is made from mRNA, which has been spliced so had its introns removed.