Cells are the basic building blocks of all living things. Animal cells contain a nucleus, cytoplasm, and cell membrane, while plant cells also have a cell wall and chloroplasts. Cells combine to form tissues, tissues combine to form organs, and organs combine to form organ systems that work together to form a whole organism. The document then discusses the major human organ systems - circulatory, digestive, excretory, nervous, and respiratory - and gives examples of the organs that make up each system.

1. How living things are built.

2. Animal and plant cells
Animal cell Plant cell
Cell
membrane
nucleus
cytoplasm
Cell wall
cytoplasm
Sap
vacuole
chloroplast
Nucleus
Cell
membrane

3. Cell structures
Animal cell Plant cell Comment
Cell
membrane
Cytoplasm
Nucleus
Cell wall
Chloroplast
Sap Vacuole
present
present
present
present
present
present
present
present
absent
It controls what goes in and out of
the cell
absent
Jelly-like substance that fills the
cell
Controls the cell.
It keeps the cell’s shape fixed
Absorbs light to make food by
photosynthesis
A place where the cell may store
food or wastes
absent
present

4. Lets start from the beginning.
 A cell is the building block of every living thing. Example:
muscle cell.
 A group of similar cells working together makes a tissue,
example: muscle tissue.
 A group of different tissues working together makes an
organ, example: heart.
 A group of different organs working together makes an
organ system, example: circulatory system.
 Many different organ systems make up an organism!!

6. Tissues

7. Human Organs
Heart Lungs Liver
Stomach Brain Kidney
Tongue skin Blood vessels

8. Plant organs

10. Circulatory system
 Main job: to pump blood
around the body.
 Organs: Heart, blood
vessels.

11. Digestive system
 Main job: breaks
down food into small
molecules.
 organs: tongue, teeth,
gullet (oesophagus),
stomach, liver,
pancreas, small
intestine, large
intestine.

12. Excretory system
 Main job: to remove
wastes from the blood.
 Organs: kidneys, urinary
bladder.

13. Nervous system
 Main job: send messages
from one part of the
body to another.
 Organs: Brain, spinal
cord, nerves.

14. Respiratory system
 Main job: to oxygenate
blood and remove carbon
dioxide.
 Organs: mouth, nose,
windpipe, lungs,
diaphragm.