Many organisms are multicellular, with cells that carry out different roles.These specialised cells are organised into tissues which are organised into organs and then into organ systems which make up the whole organism.Cells start off as simple cells but are then differentiated after mitosis.In order for differentiation to occur, some genes are switched on and some genes are switched off.TissuesA tissue is a collection of differentiated cells that are adapted to perform a specialised function or functions within the organism.There are four main types of tissues in animals:nervous tissueepithelial tissuemuscle tissueconnective tissue
Specialised Cells and Tissues
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Specification: OCR Biology A (H020), AS-level, 2.1.6 Cell division, cell diversity and cellular organisation. Topic: Cell Division.
Key terms in this lesson
- mitosis
- Nuclear division producing two daughter nuclei that are genetically identical to the parent nucleus, used in growth, repair and asexual reproduction.
- differentiation
- The process by which unspecialised cells change to become specialised in structure and function.
- gene
- A length of DNA that codes for a specific polypeptide.
More in Cell Division
- Metaphase 1
- Anaphase 1
- Telophase 1
- Meiosis 2
- Epithelial Cells
- Specialised Plant Cells
- Organs and Organ Systems
- Stem Cells
All 31 lessons in Cell Division · All OCR AS-level Biology topics