Biology·Cambridge A-Level

Cell structure

Syllabus Learning Objectives

01define resolution and magnification and explain the differences between these terms, with reference to light microscopy and electron microscopy

02recognise 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

03describe and interpret photomicrographs, electron micrographs and drawings of typical plant and animal cells

04state that cells use ATP from respiration for energy-requiring processes

05outline key structural features of a prokaryotic cell as found in a typical bacterium, including: • unicellular • generally 1–5 µm diameter • peptidoglycan cell walls • circular DNA • 70S ribosomes • absense of organelles surrounded by double membranes

06state that all viruses are non-cellular structures with a nucleic acid core (either DNA or RNA) and a capsid made of protein, and that some viruses have an outer envelope made of phospholipids

07calculate magnifications of images and actual sizes of specimens from drawings, photomicrographs and electron micrographs (scanning and transmission)

08define resolution and magnification and explain the differences between these terms, with reference to light microscopy and electron microscopy

09describe and interpret photomicrographs, electron micrographs and drawings of typical plant and animal cells

10compare the structure of typical plant and animal cells

11compare the structure of a prokaryotic cell as found in a typical bacterium with the structures of typical eukaryotic cells in plants and animals

12make temporary preparations of cellular material suitable for viewing with a light microscope

13draw cells from microscope slides and photomicrographs

14use an eyepiece graticule and stage micrometer scale to make measurements and use the appropriate units, millimetre (mm), micrometre (µm) and nanometre (nm)