Biology 9700/11 May June 2023 | Cambridge AS Level Past Papers With Mark Scheme

- Electron micrograph analysis of onion root cells, freeze-fracture technique, cell membrane structures, ribosomes, nuclear envelope, plasmodesma.
- Cell structures capable of vesicle formation: cell surface membrane, endoplasmic reticulum, Golgi body.
- Functions of cell structures: polypeptide synthesis, lipid synthesis, hydrolytic enzyme packaging, membrane-bound sacs, non-membrane-bound structures.
- Tonoplast presence in specific cell types: root hair, companion cells, sieve tube elements, endodermis.
- Organelles with double membranes: chloroplasts, mitochondria, nuclei, vacuoles.
- Mitochondrial evolution hypothesis: folded internal membrane, circular DNA, 70S ribosomes, prokaryotic features.