AS & A Level Biology (9700) — October–November 2024, Paper 21

Animal cells, plant cells and prokaryotic cells have similarities and differences in their structure. Table 1.1 lists five organelles found in cells. Complete Table 1.1 by placing…

In the mammalian circulatory system, red blood cells travel through different types of blood vessel as they pass from the heart to respiring tissues and back to the heart. Fig.…

Fig. 3.1 is a photomicrograph of a transverse section through a region of the wall of the bronchus in the gas exchange system. Tissue J is a pale region containing rounded cells…

Fig. 4.1 shows the structure of sucrose, a disaccharide produced by plant cells (an alpha-glucose ring joined to a fructose ring by an oxygen bridge). Name the covalent bond that…

Trypsin is an enzyme which catalyses the hydrolysis of casein, a protein found in milk. Milk that contains casein has a cloudy, white appearance. As the casein is hydrolysed by…

Fig. 6.1 shows a plant cell in a stage of mitosis (a photomicrograph showing chromosomes separating towards opposite poles with a clearly visible spindle). Some of the structures…