Biology - Paper 1
Cells & Organisation
C1 – Cell Structure & Transport:
1.1 - Microscopes:
Throughout time, microscopes have increased in magnification and stopped colour distortion and
low resolution. Resolution is ability to see finer details
LIGHT ELECTRON
Can see colour Can't see colour
Low resolution High resolution
Low magnification High magnification
Shines light through Uses electrons
Can see living specimen Can't see living specimen
As electron microscopes have higher magnification and resolving power, you can see sub-cellular
structures clearer. The mitochondria being discovered supports this.
Total Mag = Eye Piece x Objective
Magnification = Image Size/Real Size
Micrometres (um) = 0.000001m OR 1x10-6 e.g. cells
Nanometres (nm) = 1x10 –9 e.g. DNA
Goes down –3 power for metre to milli to micro to nano
,1.2 - Animal and Plant Cells:
Cell Wall – Made of cellulose, strengthens plant cell
Cell Membrane – Controls what goes in and out of the cell
Ribosomes – Where protein synthesis occurs
Nucleus – Controls genes and activities of cell
Vacuole – Cell sap keeps cells shape proper
Cytoplasm – Most chemical reactions take place
Mitochondria – Site of aerobic respiration
Chloroplast – Produces energy via photosynthesis
1.3 - Eukaryotic and Prokaryotic Cells:
Eukaryotic have a cell membrane, cytoplasm, and genetic material in a nucleus. Examples are plant
and animal cells.
Prokaryotic are a single-celled organisms and the genes are not in the nucleus. Examples are bacteria
cells.
Flagellum – Long protein to help cell movement
Plasmid - DNA
, 1.4 - Specialisation in Animal Cells:
Sperm Cells – Specialised for reproduction. Adaptations are a long tail + streamlined head for
swimming. Also contains lots of mitochondria for energy and enzymes to digest through egg cell
membrane.
Nerve Cells – Carry electrical signals. Adaptations are long, branched connections (dendrites) to form
a network, an axon (carries nerve impulses) which is very long and synapses where they can pass
impulses to another cell using special transmitter chemicals. They also contain lots of mitochondria.
Muscle Cells – Contract and relax. Adaptations are special proteins which slide over to make fibres
contract, lots of mitochondria and can store glycogen for further energy.
1.5 - Specialisation in Plant Cells:
Root Hair Cells – They take in water and give it to the xylem. Adaptations are large surface area,
large permanent vacuole to speed up osmosis and lots of mitochondria for active transport.
Photosynthetic Cells – They carry out photosynthesis. Adaptations are they have chloroplasts with
chlorophyll, positioned in continuous layers in leaves and outer layers of the stem, and a large
permanent vacuole to keep cell rigid, and keep leaf spread out to get maximum light.
Xylem Cells – Transport tissue carrying water and mineral ions from roots to highest leaves and
shoots. Xylem is made of xylem cells which dies due to lignin and they form long hollow tubes. Lignin
spirals are strong and help withstand the pressure of water moving up the plant.
Phloem Cells - Carries food made by photosynthesis around the plant. Phloem cells do not become
lignified and die. Their adaptations are sieve plates which allow water carrying dissolved food to
move freely up and down tubes. Also, Phloem cells have companion cells to help internal structures
stay alive and their mitochondria transfer energy to move dissolved food up and down the plant.
1.6 - Diffusion:
Diffusion – Movement of molecules in a gas/solution from a higher to lower concentration, e.g. urea,
gas exchange, osmosis.
Factors affecting diffusion are temperature as a higher temperature cause particles to move more
and the surface area of the membrane affects the rate of diffusion. Larger surface area = more
Cells & Organisation
C1 – Cell Structure & Transport:
1.1 - Microscopes:
Throughout time, microscopes have increased in magnification and stopped colour distortion and
low resolution. Resolution is ability to see finer details
LIGHT ELECTRON
Can see colour Can't see colour
Low resolution High resolution
Low magnification High magnification
Shines light through Uses electrons
Can see living specimen Can't see living specimen
As electron microscopes have higher magnification and resolving power, you can see sub-cellular
structures clearer. The mitochondria being discovered supports this.
Total Mag = Eye Piece x Objective
Magnification = Image Size/Real Size
Micrometres (um) = 0.000001m OR 1x10-6 e.g. cells
Nanometres (nm) = 1x10 –9 e.g. DNA
Goes down –3 power for metre to milli to micro to nano
,1.2 - Animal and Plant Cells:
Cell Wall – Made of cellulose, strengthens plant cell
Cell Membrane – Controls what goes in and out of the cell
Ribosomes – Where protein synthesis occurs
Nucleus – Controls genes and activities of cell
Vacuole – Cell sap keeps cells shape proper
Cytoplasm – Most chemical reactions take place
Mitochondria – Site of aerobic respiration
Chloroplast – Produces energy via photosynthesis
1.3 - Eukaryotic and Prokaryotic Cells:
Eukaryotic have a cell membrane, cytoplasm, and genetic material in a nucleus. Examples are plant
and animal cells.
Prokaryotic are a single-celled organisms and the genes are not in the nucleus. Examples are bacteria
cells.
Flagellum – Long protein to help cell movement
Plasmid - DNA
, 1.4 - Specialisation in Animal Cells:
Sperm Cells – Specialised for reproduction. Adaptations are a long tail + streamlined head for
swimming. Also contains lots of mitochondria for energy and enzymes to digest through egg cell
membrane.
Nerve Cells – Carry electrical signals. Adaptations are long, branched connections (dendrites) to form
a network, an axon (carries nerve impulses) which is very long and synapses where they can pass
impulses to another cell using special transmitter chemicals. They also contain lots of mitochondria.
Muscle Cells – Contract and relax. Adaptations are special proteins which slide over to make fibres
contract, lots of mitochondria and can store glycogen for further energy.
1.5 - Specialisation in Plant Cells:
Root Hair Cells – They take in water and give it to the xylem. Adaptations are large surface area,
large permanent vacuole to speed up osmosis and lots of mitochondria for active transport.
Photosynthetic Cells – They carry out photosynthesis. Adaptations are they have chloroplasts with
chlorophyll, positioned in continuous layers in leaves and outer layers of the stem, and a large
permanent vacuole to keep cell rigid, and keep leaf spread out to get maximum light.
Xylem Cells – Transport tissue carrying water and mineral ions from roots to highest leaves and
shoots. Xylem is made of xylem cells which dies due to lignin and they form long hollow tubes. Lignin
spirals are strong and help withstand the pressure of water moving up the plant.
Phloem Cells - Carries food made by photosynthesis around the plant. Phloem cells do not become
lignified and die. Their adaptations are sieve plates which allow water carrying dissolved food to
move freely up and down tubes. Also, Phloem cells have companion cells to help internal structures
stay alive and their mitochondria transfer energy to move dissolved food up and down the plant.
1.6 - Diffusion:
Diffusion – Movement of molecules in a gas/solution from a higher to lower concentration, e.g. urea,
gas exchange, osmosis.
Factors affecting diffusion are temperature as a higher temperature cause particles to move more
and the surface area of the membrane affects the rate of diffusion. Larger surface area = more
