quiz!

• Electron microscopes


  Have higher resolving power or resolution, allowing finer details to be visualized
• 5 micrometers


  5 * 10^-6 meters
• Subcellular structures/organelles only found in plant cells


  • Chloroplasts
  • Permanent vacuole
  • Cell wall
• Eukaryotic cells


  DNA is found in the nucleus
• Prokaryotic cells


  DNA is not found in a nucleus
• Stages of mitosis


  1. Nucleus dissolves

  2. Genetic material is duplicated

  3. Two sets of chromosomes move to opposite sides

  4. Organelles are duplicated

  5. Cell divides producing two genetically identical diploid cells
• Diploid human cells

  Have 23 pairs or 46 chromosomes
• Haploid human cells

  Have 23 chromosomes
• Diffusion


  Movement of particles from high to low concentration, down the concentration gradient, passive
• Osmosis


  Diffusion of water through a semi-permeable membrane to balance the concentration of solutions
• Active transport


  Movement of molecules from low to high concentration, against the concentration gradient, requires energy
• Factors that increase rate of diffusion/osmosis

  • Increase temperature
  • Increase concentration difference
  • Increase surface area
• Finding sugar concentration in potato using osmosis practical

  Interpolate using line of best fit where it crosses x-axis, this is the concentration where no osmosis occurs, which is the same as inside the potato cells
• Bile


  Made by liver, stored in gallbladder, emulsifies lipids in small intestine to increase surface area for enzyme action
• Amylase


  Enzyme secreted by salivary glands and pancreas that breaks down starch into glucose
• Villi


  Cells in small intestine with large surface area to absorb nutrients
• Enzymes


  Biological catalysts that facilitate crucial processes
• Enzyme specificity


  Enzymes only break down certain molecules due to lock and key nature of active site
• Factors affecting enzyme activity

  • Increasing temperature increases activity until denaturation
  • Optimum pH range
• Carbohydrases, proteases, lipases


  Break down carbohydrates into sugars, proteins into amino acids, lipids into fatty acids and glycerol respectively
• Detecting complete starch breakdown in enzyme practical

  Solution no longer turns black/changes colour with iodine
• Tests for biological molecules

  • Starch - iodine turns black
  • Sugars - Benedict's solution turns orange
  • Proteins - Biuret reagent turns purple
  • Lipids - ethanol turns cloudy
• Alveoli


  Air sacs in lungs with large surface area for gas exchange
• Red blood cells


  Biconcave shape maximizes surface area for oxygen binding to hemoglobin
• Blood flow through heart

  1. Enters through vena cava

  2. Right atrium

  3. Right ventricle

  4. Pulmonary artery

  5. Lungs

  6. Pulmonary vein

  7. Left atrium

  8. Left ventricle

  9. Aorta
• Differences between left and right side of heart

  Left side has thicker walls to pump blood to whole body at higher pressure, right side only pumps to lungs
• Differences between arteries, veins, capillaries

  • Arteries - carry blood away from heart, thick walls, small lumen
  • Veins - carry blood towards heart, thin walls, large lumen, valves
  • Capillaries - one cell thick walls for gas/nutrient exchange
• Risk factors for non-communicable diseases

  • Diabetes - poor diet, obesity
  • Heart disease - poor diet, lack of exercise
  • Liver disease - alcohol
  • Lung disease - smoking
• Cancer


  Uncontrolled cell division resulting in tumours, benign cancers don't spread, malignant cancers do
• Xylem


  Unbroken tubes that carry water up plant by transpiration
• Phloem


  Tubes that transport sugars and other molecules up and down plant
• Factors increasing transpiration rate

  • Increase temperature
  • Increase air flow
  • Increase leaf surface area
• Meristem


  Where new plant cells are made, stem cells that then differentiate
• Leaf structures and functions

  • Waxy cuticle - prevents water loss
  • Palisade mesophyll - site of most photosynthesis
  • Spongy mesophyll - gas exchange
  • Guard cells - control stomata
• Word and balanced equations for respiration and photosynthesis

  Respiration: Glucose + Oxygen -> Carbon dioxide + Water + Energy

  Photosynthesis: Carbon dioxide + Water + Light Energy -> Glucose + Oxygen
• Anaerobic respiration in animals and plants

  Animals - Glucose -> Lactic acid

  Plants - Glucose -> Ethanol + Carbon dioxide
• Uses of glucose from photosynthesis

  • Respiration
  • Starch/fat storage
  • Cellulose production
  • Amino acid synthesis
• Factors increasing photosynthesis rate

  • Increase temperature
  • Increase light intensity
  • Increase carbon dioxide concentration
• Light intensity and distance from light source

  Light intensity decreases by inverse square of distance
• Limiting factor for photosynthesis is likely carbon dioxide concentration