Cells and Genetic material

• CELL THEORY

  • All organisms consist of one or more cells
  • The cell is the basic unit of structure and function: they are building blocks capable of carrying out all life processes.
  • All cells came from pre-existing cells.
  • Cell contains instructions for growth, development, function, and division.
• Cell is the basic unit of life.
• Both types of cell contain genetic material in the form of the chemical DNA — this contains instructions that control the activities of the cell, and allows the  whole organism to develop and function as it should.  
• Genetic material is stored differently in eukaryotic and prokaryotic cells. 

  • Nucleus - eukaryotes
  • Cytoplasm - prokaryotes
• Organelles  -  Subcellular structures.
• Prokaryotic cells 

  • No nucleus, smaller and simpler.
  • Don’t contain mitochondria or chloroplasts. 
  •  They store their genetic material in plasmids and in one long circular chromosome, which floats free in the cytoplasm.
  • Bacteria cell
• Eukaryotic cells

  • Have a nucleus, and are more complex.
  • Plant cell
  • Animal cell
  • Fungal cell
• ANIMAL CELL

  • Nucleus
  • Nuclear membrane
  • Cell membrane
  • Mitochondria
  • Vesicle
  • Cytoplasm
• PLANT CELL

  • Nucleus
  • Nuclear membrane
  • Cell membrane
  • Cell wall
  • Mitochondria
  • Vesicle
  • Cytoplasm
  • Vacuole
• BACTERIA CELL

  • Cell membrane
  • Chromosomal DNA
  • Plasmids
  • Ribosomes
  • Cytoplasm
  • Pili
  • Flagellum Does not contain nucleus, mitochondria and chloroplast.
• Nucleus

  • Contains the genetic material (DNA) that controls the work of the cell.
• Nuclear membrane

  • Controls what goes in and out of the nucleus.
• Cell membrane

  • A semipermeable barrier that controls what goes in and out of the cell.
• Mitochondria

  • Powerhouse of the cell.
  • Important in cell respiration.
  • Contain the enzymes needed to control most of the chemical reactions.
• Ribosomes

  • Where proteins are synthesised.
• Vesicles

  • Carries useful substances or waste products 
• Cytoplasm

  • Gel-like substance where organelles are found and are held together, and where the work of the cell takes place.
• Cell wall

  • Made of cellulose.
  • A very strong chemical which stops the cell from bursting — is like a scaffolding around a building.
  • Reason why plant cells are erect.
• Chloroplast

  • Where photosynthesis occurs (make sugar by using light).
  • Contains a green pigment which traps light.
• Large central vacuole

  • Storage of food, water, salts and sometimes pigments of a plant cell.
  • Contains cell sap, a weak solution of sugar salts.
• Tonoplast

  • Outer covering of the vacuole.
• Chlorophyll

  • Green pigment.
• Chromosomal DNA

  • One long circular chromosome that controls the cell’s activities and replication.
  • Floats free in the cytoplasm.
• Plasmids

  • Small loops of extra DNA that aren’t part of the chromosome.
  • Contains genes for drug resistance, which can be passed between bacteria. (not all prokaryotic cells contain plasmids)
• Flagella

  • Tail of the bacteria cell.