AS & A Level Biology (9700) — October–November 2023, Paper 22
6 questions · every question answerable online with instant point-by-point AI marking against the official mark scheme.
Start with Question 1 →During interphase and mitosis of the cell cycle, the chromosomes within a cell go through a number of changes. Each chromosome is composed of DNA complexed with proteins. In…
Answer this question and get it marked →Keratin is the structural protein in feathers of birds. Keratin polypeptides are composed of a high proportion of cysteine amino acids, which have sulfur-containing R groups.…
Answer this question and get it marked →The liver receives blood from the hepatic artery and from the hepatic portal vein. The hepatic portal vein transports blood from the digestive system. Hepatocytes are the main…
Answer this question and get it marked →The alveoli of the lungs are the main gas exchange surface in humans. Explain how blood flow through the alveolar capillaries helps to maintain steep diffusion gradients for gas…
Answer this question and get it marked →Tuberculosis (TB) is an infectious disease caused by a bacterium. In the majority of people, only the lungs are affected. In most cases, the transmission of TB from an infected…
Answer this question and get it marked →Water that is absorbed from the soil solution by the roots of a plant enters xylem vessels and is transported to the leaves and buds. Fig. 6.1: a spider diagram listing four…
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