# Cells, Tissues and Organs

Source: https://projectgcse.co.uk/biology/life_processes_cell_activity/cells_tissues_and_organs

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Cells are the basic unit of all living things. The different parts of cells include:

- Protoplasm - consists of cytoplasm and nucleus
- Cytoplasm - jelly like substance where chemical reactions take place and other parts are embedded
- Nucleus - controls reproduction and also contains the characteristics of the cell
- Cell membrane - surrounds the cell and controls what moves in and out of the cell
- Mitochondria - found only in plant cells where respiration occurs
- Chloroplasts - make plants green. Contain chlorophyll which is needed for photosynthesis
- Cell wall - gives the cell its shape. The cell "skeleton"
- Vacuoles - where the cell sap is stored

#### **Plant cell**

- Chlorophyll in chloroplasts
- Cellulose cell wall
- Large vacuoles

#### **Animal cell**

- No Chlorophyll or chloroplasts
- No Cellulose cell wall
- Small or no vacuoles

#### **Tissues**

- Made up of lots of cells of the same type. e.g. muscle tissue is made up of many muscle cells

#### **Organs**

- Different tissues working together to carry out a certain function. An organ can contain different types of tissue e.g. the heart