Cells

• Tissue


  A group of cells working together to perform a function E.g. Skin, muscle, liver, brain

  
• Cell


  The building blocks of all living organisms. Cells can be prokaryotic or eukaryotic

  
• Eukaryote


  Plant and Animal cells are eukaryotic cells as they have a cell membrane, cytoplasm and a nucleus

  
• Prokaryote


  Bacterial cells are prokaryotic cells as they are very very small have a cell wall around their cell membrane and they do not have a nucleus

  
• Cell Membrane


  An envelope that surrounds the cell and lets substances in and out

  
• Nucleus


  Contains DNA and controls the cells activity

  
• Cytoplasm


  The jelly centre of the cell which holds the sub-cellular structures and is where all the chemical reactions happen

  
• Cell Wall


  Only found in plant cells and bacterial cells. In plant cells the cell wall is made of cellulose

  
• Single DNA Loop


  In prokaryotic cells (bacteria) the DNA is found as a single loop

  
• Plasmid


  A small ring of DNA found in prokaryotic cells (bacteria)

  
• Mitochondria


  This is where respiration happens in cells which gives the cells energy

  
• Chloroplasts


  Only found in plant cells, these contain chlorophyll and are the sites of photosynthesis and are green

  
• Ribosomes


  Where proteins are made

  
• Vacuole


  Found in plant cells, these contain cell sap which is sugar and water

  
• Specialisation


  When a cell becomes specialised for a specific job. E.g. liver cells, heart cells, sperm cells.

  
• Organ


  An organ is made up of different tissues and has a specific job. E.g. the heart's job is to pump blood around the body.

  
• Organ System


  An organ system contains more than one organ working together. E.g. the cardiovascular system consists of the heart, lungs and blood.

  
• Sperm Cells


  A sex cell produced in the testes which carries genetic information from the male to the female egg. They have a tail to swim, lots of mitochondria for energy, and an acrosome which contains enzymes to digest through the egg membrane.

  
• Nerve Cells


  These are special cells which carry electrical impulses along a long structure called an axon. The brain is made of nerve cells. They are also known as neurones.

  
• Muscle Cells


  These make up muscle tissue and contract and relax to create movement. There are three types - smooth muscle, cardiac muscle and skeletal muscle. Muscle cells contain a lot of mitochondria as they need lots of energy

  
• Root Hair Cell


  A cell found in the roots of a plant which has a long part sticking out to increase the surface area for absorbing water and minerals. They also have NO chloroplasts as they do not photosynthesise

  
• Xylem Cell


  A cell that makes up xylem tissue in a plant. Xylem tissue is like a long tube that carries water from the roots of a plant to the leaves

  
• Phloem Cell


  A cell that makes up phloem tissue in a plant. Phloem tubes allow food like sugars to be moved around a plant.

  
• Differentiation


  The process that cells go through to become specialised.

  
• Light Microscope


  A microscope that uses light and a series of lenses to magnify things.

  
• Electron Microscope


  A microscope that fires electrons at objects and then creates a very detailed image.

  
• What 3 organelles do plant cells have that animal cells don't? what do they do? (3)

  - Chloroplast - absorb light for photosynthesis

  - vacuole - stores cell sap - structure and support (keeps cell rigid)

  - Cell wall - made of cellulose - structure and supportSee an expert-written answer!We have an expert-written solution to this problem!
• What are 4 key features of bacterial cells? (4)

  - Small size

  - Cell wall

  - Cell membrane

  - loop of DNA (no nucleus)
• describe how the body is organised starting at cells (3)

  Cells - Tissue - Organs - Organ System
• Meristems


  Unspecialised cells (stem cells) in plants
• Actual = Image / Magnification


  Calculating actual size of a cell
• 1000


  The number of micrometres in a mm