AM 7401
2023 AQA AS BIOLOGY 7401/1 Paper 1 Question
Paper & Mark scheme with 100%verified solution
Contrast the structures of ATP and a nucleotide found in DNA to give two
differences. - answers - ATP has ribose and DNA nucleotide has deoxyribose
- ATP has 3 phosphate groups and DNA nucleotide has 1 phosphate group
Name the process by which fatty acids and glycerol enter the intestinal
epithelial cell. - answers diffusion
Explain the advantages of lipid droplet and micelle formation. - answers -
droplets increase surface areas for lipase enzyme action
- so faster hydrolysis of triglycerides
- micelles carry fatty acids and glycerol through the membrane to
intestinal epithelial cell.
Suggest how the golgi apparatus is involved in the absorption of lipids. -
answers - modifies triglycerides
- combines triglycerides with proteins
- packaged for exocytosis
Explain the role of the heart in the formation of tissue fluid. - answers -
contraction of ventricles produces a high blood pressure
- this forces water out of the blood capillaries
Suggest how a blockage in the lymphatic system could cause lymphoedema. -
answers excess tissue fluid cannot be reabsorbed
Which test could scientists use to identify that there are amino acids in white
wine? - answers Biuret
Name the chemical element found in all amino acids that is not found in
triglycerides. - answers nitrogen
Explain how the chromosome number is halved during meiosis. - answers -
there's homologous chromosomes
- one of each pair goes to each daughter cell
Describe the process of crossing over and explain how it increases genetic
diversity. - answers - homologous pairs of chromosomes form a bivalent
- chiasma is formed
- equal lengths of non-sister chromatids are exchanged
- this produces new combinations of alleles
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