Xxxx

Page 1 of 4

Xxxx

By | Jan. 2013
Page 1 of 4
Biology 2-Life processes
Plant and animal cells
plant cell
Has all the bits that the animal cell has plus:
Permanent Vacuole- contains cell sap, weak solution of sugar and salts. Nucleus-contains genetic material and controls activities of cells Cytoplasm-gel like substance where all the chemical reactions take place Cell membrane- holds cell together and controls what goes IN and OUT Mitochondria- reactions for respiration takes place Ribosomes-proteins are made here

Lots of cells= tissues = organs = organ systems
Specialised cells-Palisade cells, Guard cells,Red blood cells and sperm and egg cell

-Palisade cells are packed with chloroplasts for photosynthesis. - Crammed at top of cell so are near light.
-Tall shape means lots of surface area for absorption of Carbon dioxide. -Thin shape means that you can pack lots of them at the top of the leaf.

Red Blood cells
Concave shape gives big surface area for aborption of oxygen and can pass through capillaries. Packed with haemoglobin- pigment that absorbs oxygen No nuclues- so have enough room for the haemoglobin, important part of blood, blood is a tissue. Sperm and egg cell

Main functions of an egg cell are to carry the female DNA and nourish the developing embryo in the early stages. * When sperm fuses with egg, the eggs membrane changes its structure to stop any sperm from getting in. This is so the offspring end up with the right amount of DNA. Function of sperm is to get the male DNA to the female DNA. Has long tail, and streamlined head to help it swim to egg. Mitonchondria are in the cell to provide energy needed. Sperms carry enzymes in head to digest through the egg cell membrane.

Guard cells- Open and close pores
Special kidney shape which opens and closes pores in a leaf. When plant has lots of water it goes plump and turgid. Makes stomata open so gases are exchanged for photosynthesis. When plant is short of water the guard cell becomes flaccid,making the...