In 2021, as in other years, examiners applied strict criteria to biological drawings. If you are looking for the "answers" regarding how to score marks here, it is rarely about artistic talent and entirely about adherence to rules:
“Because heat kills the enzyme.” (Too vague – no mention of denaturation or active site.)
Candidates were asked to explain why agar cubes are limited as models for cells: Permeability: o level biology practical 2021 answers
. Catalase has a specific active site shape that is only complementary to the substrate hydrogen peroxide. Experimental Accuracy:
"Replace the enzyme solution with 2 cm³ of distilled water (or boiled enzyme) while keeping all other conditions identical, to confirm that any gas production is due to enzymatic activity." In 2021, as in other years, examiners applied
A: No. But the experimental themes (osmosis, enzymes, food tests, photosynthesis) repeat 90% of the time.
Always include clear headings with appropriate units (e.g., Time / min or Temperature / °C ). Do not put units inside the data cells. Experimental Accuracy: "Replace the enzyme solution with 2
, and the sample size may not be large enough to reflect the theoretical probability perfectly. Answer Summary Critical Fact/Answer Catalase is specific due to the shape of its active site. Data Collection
Visking tubing (containing Solution B) was placed in a test tube of Solution A. Observations & Answers:
Biuret reagent turns from blue to purple/violet if protein is present.
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