CSEC BIOLOGY

• This is a paper one review for the 2022 C-SEC Biology examination
• It is important to read the instructions carefully and understand each one before starting the examination
• Insect


  Has 3 segments: head, thorax, abdomen
• Quadrat


  Sampling method used to estimate the density of slow moving or immobile organisms
• Niche


  The role an organism plays in its environment
• Habitat


  The place where an organism lives
• Trophic level one in the food web is represented by the producer, phytoplankton
• Biodegradation


  The breakdown of living things by bacteria
• Relationships that may present harm

  • Parasitism
  • Predation
• Energy transfer in food chains

  Only 10% of energy stored in food is available to the next organism, most is lost as heat during respiration
• Non-biodegradable materials


  • Sardines
• Reforestation


  Replanting trees on a bare hillside
• Increase in contraceptives and diseases


  Decrease in population size from 1980-1989
• Nucleus


  Organelle responsible for controlling cellular activities
• Cell wall is only found in plant cells, not animal cells
• Chloroplast

  Organelle directly involved in photosynthesis
• Osmosis


  Movement of water molecules from an area of high concentration to an area of lower concentration through a semi-permeable membrane
• Autotrophs


  Organisms that derive their nutrients from simple inorganic substances like carbon dioxide and water
• Leaf


  • More chloroplasts and larger surface area enhance ability to absorb solar energy
• Reducing sugar


  Can directly change copper sulfate to copper oxide without hydrolysis
• Non-reducing sugar


  Requires hydrolysis to break down into simple sugars before reacting with Benedict's solution
• Tooth pulp


  Contains a large number of blood vessels and nerves
• Enzyme-controlled reactions


  • Enzyme activity is low at low temperatures, increases as temperature rises, then decreases at very high temperatures
• Enzyme controlled reaction


  Enzymes are inactive at low temperatures, become more active as temperature rises, then decline in activity at high temperatures
• Enzyme activity


  • Highest at optimal temperature, close to body temperature of organism
  • Declines after optimal temperature as enzymes become denatured
• A 50 year old male is advised by his doctor to pay special attention to the amount of salt in his diet
• Hypertension


  High chance of developing due to high salt intake
• Sickle cell anemia is caused by low iron or low hemoglobin in red blood cells
• The structure shown in the diagram is an alveolus
• Alveolus


  • Large surface area
  • Thin walls
  • Covered in capillaries
  • Moist
• Nicotine in cigarettes


  Increases heart rate
• Nicotine reduces the uptake of oxygen by the capillaries, not the transport of oxygen in the blood
• Diffusion


  Effective for oxygen uptake in small organisms like amoeba, but not in larger organisms like humans which require specialised respiratory surfaces
• Transport substances in animals

  • Amino acids
  • Hormones
• Mineral ions required for blood clotting

  • Potassium
  • Calcium
• Artificial immunity


  Immunity acquired through deliberate exposure to pathogens, not from the mother
• High sun and high wind

  Increase the rate of transpiration in plants
• Source


  Area of the plant where sucrose is loaded into the phloem
• The potato tuber contains the most starch
• Proximal


  Closer to the Bowman's capsule in the nephron