Cells, tissues and organs What are animals and plants made of?

Animals and plants are made of cells Animals and plants are made of cells. Cells form the basic "building blocks" for living things. Some cells have specialised functions. Tissues are made from cells of a similar type. Organs are made from tissues, and systems are made from several organs working together.

Animal cells and plant cells Animal cells usually have an irregular shape, and plant cells usually have a regular shape Cells are made up of different parts.

The parts of cells Part Function Found in Cell membrane Controls what substances can get into and out of the cell. Plant and animal cells Cytoplasm Jelly-like substance, where chemical reactions happen. In plant cells there's a thin lining, whereas in animal cells most of the cell is cytoplasm. Nucleus Controls what happens inside the cell. Carries genetic information. Don't call the nucleus the 'brain' of the cell - not a good description

Human chromosomes – 23 pairs

The parts of cells Part Function Found in Chloroplast Where photosynthesis happens – chloroplasts contain a green substance called chlorophyll. Plant cells only Vacuole Contains a liquid called cell sap, which keeps the cell firm. Cell wall Made of a tough substance called cellulose, which supports the cell.

Cells and their functions Humans are multi-cellular animals. That means we are made of lots of cells, not just one cell. The cells in many multi-cellular animals and plants are specialised, so that they can share out the processes of life. They work together like a team to support the different processes in an organism. Specialised cells Different cells have special features related to their particular functions. The tables below show examples of some specialised animal and plant cells, with their functions and special features.

Type of animal cell Function Special features Red blood cells To carry oxygen Large surface area, for oxygen to pass through Contains haemoglobin, which joins with oxygen Nerve cells To carry nerve impulses to different parts of the body Long Connections at each end Can carry electrical signals Female reproductive cell (egg cell) To join with male cell, and then to provide food for the new cell that's been formed Large Contains lots of cytoplasm Male reproductive cell (sperm cell) To reach female cell, and join with it Long tail for swimming Head for getting into the female cell

Type of plant cell Function Special features Root hair cell To absorb water and minerals Large surface area Leaf cell To absorb sunlight for photosynthesis Lots of chloroplasts

Some organisms have just a single cell

Tissues Animal cells and plant cells can form tissues, like muscle tissue. A living tissue is made from a group of cells with a similar structure and function, which all work together to do a particular job. Here are some examples of tissues: muscle the lining of the intestine the lining of the lungs phloem (tubes that carry dissolved sugar around a plant) root hair tissue (for plants to take up water and minerals from the soil)

Organs An organ is made from a group of different tissues, which all work together to do a particular job. Here are some examples of organs: heart lung stomach brain leaf root

Organ systems An organ system is made from a group of different organs, which all work together to do a particular job. Here are some examples of organ systems: circulatory system respiratory system digestive system nervous system reproductive system leaf canopy

http://www.bbc.co.uk/bitesize/ks3/science/organisms_behaviour_health/cells_systems/activity/