Biology Unit 2

• Cell Memebrane - a bag that keeps everything inside of it. Mainly contains Cytoplasm (Water based mixture which is full of enzymes.)

• A Nucleus - where the DNA is kept. Tells a cell what to do (when to divide, multiply etc.)

• Cell Wall - made of cellulose which surrounds the cell membrane giving it strength and structure.

• Mitochondria - turns food into energy.

• Chloroplasts - Chlorophyll and harness light energy.

• Permenant Vacuole - a space within the cell. Usually full of watery sap which just keeps the cell firm.

Specifcally envolved to trap as much light as possible for photosynthesis.

• Regularly shaped

• Packed closely together - forming a continuous layer.

• Makes the efficent at absorbing light!

• Jam-packed with chloroplasts enables them to trap plenty of light. 

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  • Don't contain any chloroplasts!

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  • Have long, thin wall finger-like projections which grow outwards which stretch out into the soil absorbing mineral ions and water.
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  • Have a realitively large surface area - can absorb as much as possible.

Male sex cell who's job it is to fertilise an egg!

• Tadpole-like shape with a long whip-like tail.

• It's head is full of DNA  - genetic instructions to help make a baby.

• The head also carries a sack of potent enzymes which enables the cell to break through the egg cell membrane during fertillisation.

• Under the head there is Mitochondria which provides all the necessary energy.

• Crammed full of the protein, Haemoglobin.

• Transports Oxygen around the body where it's needed.

• Squashed doughnut shaped - giving them a large suface area.

• Very thin cell membrane and have no nucleus.

The movement of molecules and gases

• Gas particles or dissolved molecules in solution spread.

• Move from a region where there is a high concentration to a low concentration.

The movement of water across a cell membrane.

• a concentration gradient is needed.

• Water is going to move through the permeable membrane from a less concentrated or more dilute soloution to a more concentrated or less dilute solution.