Paper 1 biology

• Active transport

  The movement of substances from a more dilute solution to a more concentrated solution (against a concentration gradient) with the use of energy from respiration
• adult stem cell


  a type of stem cell that can form many types of cells
• agar jelly

  a substance places in pétri dishes which is used to culture microorganisms on
• cell differentiation


  the process where a cell becomes specialised to its function
• Cell membrane

  A partially permeable barrier that surrounds the cell
• cell wall

  an outer layer made out of cellulose that strengthens plant cells
• chloroplasts

  an organelle which is the site of photosynthesis
• chromosomes

  dna structures that are found in the nucleus which are made up of genes
• concentration gradient

  the difference in concentration between two areas
• diffusion

  the spreading out of particles of any substance in solution or particles of a gas resulting in a net movement from an area of higher concentration to an area of lower concentration
• embryonic stem cell

  A type of stem cell that can differentiate into most types of human cells
• eukaryotic cell

  a type of cell found in plants and animals that contains a nucleus
• magnification


  how much bigger an image appears compared to the original object
• meristematic cells


  a type of stem cell that can differentiate into any type of plant cell
• mitochondria

  an organelle which is the site of respiration
• Mitosis

  A type of cell division which produces two genetically identical daughter cells from one parent cell
• nucleus

  an organelle found in most eukaryotic cells that contains genetic material of the cell and controls the activitit’s of the cell
• organelle

  a specialised structure found inside a cell
• osmosis

  the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• plasmids


  loops of dna found in the cytoplasm of prokaryotic cells
• resolution 


  the ability to distinguish two different points in a specimen
• specialised cells

  cells that are adapted to perform a specific function
• Stem cell

  An undifferentiated cell that can divide to produce many specialised cells of the same type
• surface area


  the amount of contact an object has with its environment
• surface area to volume ratio


  the size of the object compared with the amount of area where it contacts its environment
• the cell cycle


  a series of stages preparing the cell for division
• therapeutic cloning


  producing an embryo that has the same genes as a patient
• vacuole

  An organelle that stores cell sap
• amylase

  an enzyme produced in the salivary glands and pancreas that breaks carbohydrates down into simple sugars
• aorta

  the main artery that takes oxygenated blood away from the heart to the body
• artery

  a blood vessel that carries blood at high pressures away from the heart
• benign tumour

  An abnormal cell growth that is contained within one area and dows not invade other areas of the body
• bile

  a substance made in the liver and stored in the gall bladder which is used to neutralise stomach acid in the intestine and emulsify fats
• blood

  a tissue containing red blood cells white blood cells platelets and plasma
• cancer

  a non communicable disease caused by changes in the cell that lead to uncontrolled growth and division
• capillary


  a very thin blood vessel that is used for the exchange of substances
• cell

  the basic building block of all living organisms
• communicable disease

  a disease that can be spread between individuals either directly or indirectly
• coronary heart disease

  a disease caused by the build up of fatty deposits inside the coronary artery narrowing it and reducing blood flow to the heart tissue
• enzymes

  biological catalysts that increase the rate of reactions in living organisms