biology 1

• Sub-cellular structures

  structures found in cells that include the nucleus, mitochondria, chloroplasts and ribosomes
• Nucleus


  the control centre of the cell
• Cytoplasm


  the substance found in living cells (outside the nucleus), where chemical reactions take place
• Mitochondria


  the structures in the cytoplasm where energy is produced from chemical reactions
• Cell wall


  a protective layer, found outside the cell membrane of plant, fungal and bacterial cells, that helps to support the cell
• Cellulose


  a carbohydrate that makes up the cell wall of plants
• Chloroplast

  a sub-cellular structure containing chlorophyll, which is found in plants and algae that carry out photosynthesis
• Prokaryotic


  organisms, such as bacteria, that do not have a nucleus or organelles such as mitochondria
• Eukaryotic


  cells that have a nucleus and sub-cellular organelles such as mitochondria
• Plasmid


  a small circle of bacterial DNA that is independent of the main bacterial chromosome
• Resolution


  the smallest distance apart two objects can be and still be seen as separate objects
• Electron microscope


  a device that fires electrons at a specimen to obtain a high resolution image
• Magnification


  how many times larger an image is than the real object
• Binary fission


  the process that enables a cell to split into two equal-sized, identical cells
• Agar


  a jelly made from algae that is used to culture microorganisms
• Petri dish


  a round, shallow dish used to grow bacteria
• DNA

  nucleic acid molecules that contain genetic information and make up chromosomes
• Cell cycle


  the series of growth and division events that a cell goes through during its life
• Mitosis

  cell division that forms two daughter cells, each with the same number of chromosomes as the parent cell
• Undifferentiated


  a cell that has not yet become specialised
• Stem cell

  a human embryo cell or adult bone marrow cell that has yet to differentiate
• Embryonic stem cells

  cells found in an embryo that can differentiate into any type of cell
• Adult stem cells


  cells that can differentiate into limited types of cells
• Meristems


  areas of cells in plants that can divide to form new cells
• Diffusion

  the natural movement of particles from an area of high concentration to an area of low concentration
• Concentration gradient

  a change in the concentration of a substance from one region to another
• Osmosis


  the movement of water, through a partially permeable membrane, into a solution with a lower water concentration