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

2. 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.

4. 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.

5. 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

7. Human chromosomes – 23 pairs

8. 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.

9. 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.

10. 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

11. 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

12. Some organisms have just a single cell

13. 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)

15. 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

17. 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