biology

• What is the focus of the AQA GCSE Biology paper 1?

  Cells, organization, infection and response, and bioenergetics
• What is the difference between eukaryotic and prokaryotic cells?

  Eukaryotic cells have a nucleus, while prokaryotic cells do not
• What structures can be seen with a light microscope?

  Cells and possibly the nucleus
• What advantage does an electron microscope have over a light microscope?

  It allows us to see finer details of organelles
• How can you calculate the actual size of a cell using a microscope?

  By dividing the image size by the magnification
• What is the function of the cell membrane?

  It keeps everything inside the cell and is semi-permeable
• What is the composition of the cell wall in plant cells?

  Cellulose
• What is the role of mitochondria in a cell?

  It is where respiration takes place, releasing energy
• What do ribosomes do in a cell?

  They assemble or synthesize proteins
• What is the purpose of a permanent vacuole in plant cells?

  It stores sap
• What is the function of chloroplasts in plant cells?

  They contain chlorophyll and are where photosynthesis occurs
• How many pairs of chromosomes do humans have?

  23 pairs
• What is the process of mitosis?

  It is the duplication of genetic material and division into two identical cells
• What are stem cells?

  Cells that have not yet specialized
• Where are stem cells found in humans?

  In human embryos and bone marrow
• What is diffusion?

  The movement of molecules from high to low concentration
• What is osmosis?

  The diffusion of water across a semi-permeable membrane
• How can the rate of diffusion be increased?

  By increasing concentration difference, temperature, or surface area
• What is the practical procedure for investigating osmosis using potato cylinders?

  1. Cut equal-sized potato cylinders and weigh them
  2. Place in test tubes with varying sugar concentrations
  3. After a day, remove and weigh again
  4. Calculate percentage change in mass
  5. Plot results against sugar concentration
• What are the levels of organization in biological systems?

  • Cells
  • Tissues
  • Organs
  • Organ systems
• What is active transport?

  Movement of substances against a concentration gradient using energy
• What is the function of bile in digestion?

  To neutralize stomach acid and emulsify fats
• What are enzymes?

  Biological catalysts that speed up chemical reactions
• What is the lock and key principle in enzyme activity?

  Enzymes only work with specific substrates that fit their active site
• What happens to an enzyme when it denatures?

  Its active site changes shape and no longer binds to the substrate
• What color does iodine turn in the presence of starch?

  Black
• How do you determine the optimum temperature or pH for an enzyme?

  By plotting the time taken for a reaction against temperature or pH
• What color does Benedict's solution turn in the presence of sugars?

  Orange
• What is the role of the respiratory system?

  To provide oxygen for respiration and remove carbon dioxide
• What is the pathway of air during breathing?

  From the trachea to bronchi, bronchioles, and alveoli
• What is the function of hemoglobin in red blood cells?

  To bind oxygen and transport it to cells
• What is the structure of the heart?

  The heart has four chambers: right atrium, right ventricle, left atrium, left ventricle
• What is the role of valves in the heart?

  To prevent backflow of blood
• What is the difference between arteries and veins?

  Arteries carry oxygenated blood, while veins carry deoxygenated blood
• What is the function of statins?

  To reduce cholesterol levels and fatty deposits
• What is coronary heart disease (CHD)?

  A condition caused by the buildup of fatty deposits in coronary arteries
• What is a communicable disease?

  A disease caused by a pathogen that can spread from person to person
• What is cardiovascular disease (CVD)?

  A non-communicable disease caused by internal factors
• What are examples of communicable diseases?

  Viral, bacterial, or fungal infections
• What are the main components of the circulatory system?

  • Heart
  • Blood vessels (arteries, veins, capillaries)
  • Blood