Biology 9700/22 March 2021 | Cambridge AS Level Past Papers With Mark Scheme

- Trachea structure: lumen, ciliated epithelium, perichondrium, smooth muscle presence in alveolus, bronchiole, bronchus, trachea.
- Gene definition: segment of DNA coding for proteins, enzyme synthesis, hydrolysis of starch and proteins in barley seed germination.
- Starch composition: amylose, amylopectin, polysaccharide characteristics, glucose as monosaccharide.
- Enzyme activity: α-amylase, maltase, temperature effects on enzyme efficiency, heat stability advantages in sugar syrup production.
- Immune response: cytokines from T-helper lymphocytes, testosterone synthesis in Leydig cells, hormone-receptor interactions.
- Cholera pathogen: Vibrio cholerae, risk factors post-cyclone, antibiotic mechanisms, vaccination strategies for disease prevention.