9700_s15_qp_12
A paper of Biology, 9700
Questions:
40
Year:
2015
Paper:
1
Variant:
2
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6
Ribosomes consist of two subunits, each containing rRNA. An analysis of all the 70S ribosomes from a single cell of the bacterium, Escherichia coli, showed that there were: • 38 000 rRNA molecules • 2 main types of rRNA molecule • 19 000 copies of each type of rRNA molecule How many 70S ribosomes were there in the E. coli cell?
6. Nucleic acids and protein synthesis  →  6.1. Structure of nucleic acids and replication of DNA
6. Nucleic acids and protein synthesis  →  6.2. Protein synthesis
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18
The protein p53 is produced in a cell in response to DNA damage. A scientist exposed three groups of cells, X, Y and Z, to different conditions. group of cells conditions cells were exposed to X ionising radiation Y ultra-violet light Z nicotine In which groups of cells would the scientist find large quantities of p53 mRNA?
19. Genetic technology  →  19.1. Principles of genetic technology
6. Nucleic acids and protein synthesis  →  6.1. Structure of nucleic acids and replication of DNA
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29
Resting muscle has a lower respiration rate than active muscle. The graph shows the oxygen dissociation curves for haemoglobin at carbon dioxide concentrations that are found in a resting muscle and an active muscle. P and Q are at the partial pressures of oxygen found in the lungs. R and S are at the partial pressures of oxygen found in either a resting muscle or an active muscle. percentage saturation of haemoglobin with oxygen partial pressure of oxygen / kPa S R P Q Which statements are correct?
8. Transport in mammals  →  8.2. Transport of oxygen and carbon dioxide
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