From PPQ

Question 1

Define the term exon

Answer 1

Base sequence coding for polypeptide

Question 2

Describe how a phosphodiester bond is formed between two nucleotides within a dna molecule

Answer 2

Condensation reaction
Between phosphate + deoxyribose
Catalysed by dna polymerase

Question 3

Define non coding base sequences and describe where they are positioned

Answer 3

DNA that does t code for protein
Between genes

Question 4

What is a homologous pair

Answer 4

Two chromosomes that carry the same genes

Question 5

Compare amd contrast the dna in eukaryotic and prokaryotic cells

Answer 5

Comparisons
- nucleotide structure is identical to
- nucleotides joined by a phosphodiester bond
- DNA it mitochondria + chloroplasts same as dna in prokaryotes
Contrasts
- eukaryotic DNA is longer, contains introns, is linear and associated with histones
- prokaryotic =opposite