recognise organelles and other cell structures found in eukaryotic cells and outline their structures and functions, limited to: • cell surface membrane • nucleus, nuclear envelope and nucleolus • rough endoplasmic reticulum • smooth endoplasmic reticulum • Golgi body (Golgi apparatus or Golgi complex) • mitochondria (including the presence of small circular DNA) • ribosomes (80S in the cytoplasm and 70S in chloroplasts and mitochondria) • lysosomes • centrioles and microtubules • cilia • microvilli • chloroplasts (including the presence of small circular DNA) • cell wall • plasmodesmata • large permanent vacuole and tonoplast of plant cells
explain how companion cells transfer assimilates to phloem sieve tubes, with reference to proton pumps and cotransporter proteins
draw and label xylem vessel elements, phloem sieve tube elements and companion cells from microscope slides, photomicrographs and electron micrographs