(a) Table 6.1 compares some of the features of DNA with the protein collagen. Complete Table 6.1. [Table 6.1]

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2021). The mark or mark type is shown in brackets.

1. [6] feature | DNA | collagen
2. elements | C H O N P ; | C H O N
3. monomers | (DNA) nucleotide(s) ; | amino acid(s) ; ignore any named amino acid
4. bonds between monomers | phosphodiester ; | peptide ;
5. site of production in eukaryotic cells | nucleus | ribosomes / rough endoplasmic reticulum / RER / rough ER ; A cytoplasm / Golgi (body / apparatus / complex)
6. [2] any two from:
7. 1 two membranes forming, nuclear envelope ; A nuclear envelope is composed of a double membrane
8. 2 nuclear pores too small to allow DNA to, pass through / escape ; A ora
9. 3 AVP; e.g. prevents DNA from being broken down (by enzymes) I DNA damage by enzymes protects DNA from hydrolytic enzymes idea of nuclear envelope is a barrier, between / that separates, nucleus and, cytoplasm / rest of cell
10. [2] any two from: either
11. 1 allow alveoli, to stretch and recoil (during inhalation and exhalation) or allow, lung (tissue) / named airway, to expand and recoil ; I 'contract', 'relax' and 'gas exchange' / 'respiration'
12. 2 prevent alveoli, over-stretching / bursting ;
13. 3 recoils to move air out of alveoli ; A force / expel / push / AW A alveolar duct
14. [1] interphase / S (phase) / synthesis (phase); A S1/S2 R if 'interphase + G1/G2' or 'S + G1/G2'