biology

• Movement

  Respiration

  Sensitivity

  Growth

  Reproduction

  Excretion

  Nutrition
• Red blood cells have full of haemoglobin, no nucleus and a biconcave disc to increase the surface area. Red blood cells transport oxygen from the lungs to the body's tissues.
• Sperm cell head contains the genetic material for fertilisation in a haploid nucleus. The acrosome in the head contains enzyme so that a sperm can penetrate an egg. The middle piece is packed with mitochondria to release the energy needed to swim and fertilise the egg.
• Root hair cell has very large surface area because they are really long and have hair like protection. This allows more active transport of mineral ions.
• Egg cell ​is a female sex cell. It has a haploid nucleus which holds the genetic material and a large amount of cytoplasm containing nutrients for the growth of the early embryo.
• Diffusion is the random movement of molecules move down a concentration region from higher concentration to lower concentration.
• Osmosis is the diffusion of water molecules from dilute solution to more concentrate solution across a partially permeable membrane.
• plant cell in more concentrated solution will gain water by osmosis and swell up, their cytoplasm and cell membrane are pushing against the cell wall. Unlike plant cell in pure water.
• Denature because temperature too high causing active site to change shape and substrate don't fit.
• Amylase found in saliva and pancreas. Help break down starch into monosaccharides like glucose.
• Pepsin found in stomach breaks down proteins into amino acids.
• Lipase found in pancreas, breaks down fats into fatty acids and glycerol.
• Catalase is an enzyme which breakdown of hydrogen peroxide to water and oxygen. Purpose to remove water and oxygen out of our cell.
• carbon dioxide + water → glucose + oxygen
• photosynthesis = 6CO2+6H2O → C6H12O6+6O2

  photosynthesis = carbon dioxide + water → glucose + oxygen
• Xylem vessels – transport water and minerals from the roots to the stem and leaves
• Phloem vessels – transport food materials (mainly sucrose and amino acids) made by the plant from photosynthesising leaves to non-photosynthesising regions in the roots and stem
• Water transpiration:

  1. Osmosis causes water to pass into the root hair cells, through the root cortex and into the xylem vessels
  2. xylem carried up to the leaves where it enters mesophyll cells

  So the pathway is:

  root hair cell → root cortex cells → xylem → leaf mesophyll cells
• Adhesion occurs when the water molecules cling to the xylem tissue. Adhesion provides the force to pull water up the sides of the tube in the xylem.
• Cohesion occurs when water molecules stick to each other. Cohesion causes the water in the tube of the root and stem to become one long column of fluid and nutrients. As water evaporates from the plant into the atmosphere, the column of water continues to move up to fill the space left by the water molecules that were “pulled out” of the leaves upon evaporation.
• As plant lose water, the negative pressure in the leaves brings more water upwards. Transpiration rate increase with temperature, wind, decrease with humidity. Plants also require minerals from the soil including nitrates (make protein) and magnesium (make chlorophyll).
• Veins carry blood into the heart.

  Arteries carry blood away from the heart.
• 1. deoxygenated blood enters heart through vena cava into right atrium
  2. right atrium contracts the blood moves through tricuspid valve to right ventricle
  3. right ventricle contracts then blood exits the heart through semilunar valve to the lungs via pulmonary artery
  4. blood become oxygenated in the lung then return to heart by pulmonary vein entering left atrium
  5. left atrium to bicuspid valve into left ventricle
  6. left ventricle contracts oxygenated blood exits heart past semilunar valve through aorta and travel through body
  7. repeat
• left ventricle wall is much thicker than right side because they need to pump blood at high pressure through body but the wall of both ventricle are thicker than atria walls.
• left and right side of the heart are separated by septum to separate deoxygenated and oxygenated blood
• 1. vena cava
  2. right atrium
  3. tricuspid valve
  4. right ventricle
  5. semilunar valve
  6. pulmonary artery
  7. pulmonary vein
  8. left atrium
  9. bicuspid valve
  10. left ventricle
  11. aorta
  12. apex

  
• Alimentary canal


  The digestive system
• Mouth and saliva gland

  1. Food mechanically digested in mouth by teeth

  2. Saliva chemically digests starch
• Oesophagus


  Food passes from mouth to stomach by peristalsis
• Stomach

  1. Protease enzyme breaks down protein

  2. Food churned to break into smaller pieces

  3. Hydrochloric acid maintains optimum pH for enzyme action and kills bacteria by creating extremely acidic conditions which denature enzymes within them
• Liver

  1. Makes bile (alkaline) secreted in small intestine to neutralize acidic conditions from stomach and provide suitable pH for enzymes

  2. Emulsifies fats and increases their surface area to aid digestion
• Gall bladder

  Bile is stored here
• Pancreas


  1. Secretes pancreatic juice into small intestine

  2. Contains lipase, amylase and protease to break down food for absorption
• Small intestine

  1. First part is duodenum, where acidity from stomach is neutralized and protease, lipase and amylase are secreted to break down molecules

  2. Second part is ileum, where products of digestion are absorbed into blood
• Large intestine


  1. Consists of colon, rectum and anus

  2. Remaining salts and water are absorbed here
• 1. Mouth
  2. teeth
  3. salivary glands
  4. pharynx
  5. esophagus
  6. liver
  7. stomach
  8. pancreas
  9. large intestine
  10. small intestine
  11. rectum
  12. anus

  
• 1. Vena cava
  2. right atrium
  3. tricuspid valve
  4. right ventricle
  5. semilunar valve
  6. pulmonary artery
  7. pulmonary vein
  8. left atrium
  9. bicuspid valve
  10. left ventricle
  11. aorta
  12. apex

  
• Deficit of vitamin D lead to rickets, weak soft bone, deformities, stunt in growth in children
• Deficits of iron lead to anaemia, which can cause tiredness and weakness because no energy produce
• Deficits of vitamin c cause scurvy, bone and blood vessel disease, bleeding in hand and feet in extreme case death