Biology

• Predator


  An organism that catches and feeds on other living organisms
• Prey


  An organism that is hunted and eaten
• Decomposers

  Microscopic bacteria and fungi which feed on dead or decaying remains of plants and animals and their waste
• Food chain

  A sequence of organisms that shows how energy from food passes from plants to animals and other animals in series
• Producer

  An organism that can manufacture its own food using energy from the sun, carbon dioxide and water
• Consumer


  An organism that cannot manufacture its own food and relies on other living organisms to provide them with nutrients
• Trophic levels

  The feeding positions occupied by each organism in a food chain
• Food web

  A complex network of food chains that shows the feeding relationships of organisms within an ecosystem
• Classification

  Groups organisms based on their unique characteristics
• Symbiotic relationship

  Where 2 species live in close association for long periods of time
• Parasitism

  • One organism benefits while the other suffers a disadvantage
• Commensalism

  • One organism benefits and the other is unaffected
• Mutualism

  • Both organisms benefit
• Evaporation

  Change of water to a vapour from the surface of various bodies of H2O
• Transpiration

  Evaporation of H2O from the surface of plants
• Condensation

  Vapour cools and changes back to liquid form
• Precipitation

  Water falls back to the earth's surface
• Osmosis

  Movement of molecules from an area of high concentration to an area of low concentration through a semi-permeable membrane
• Chemical Digestion


  The process of breaking down food into smaller molecules using enzymes and acids
• Digestion in the mouth

  1. Saliva is secreted by 3 pairs of salivary glands

  2. Saliva contains water, mucous and the enzyme salivary amylase

  3. Salivary amylase breaks down starch into maltose

  4. Mouth has a slightly alkaline to neutral pH (6-7)
• Digestion in the oesophagus


  1. Muscular tube connecting mouth to stomach

  2. Muscular walls contract and relax to push food along by peristalsis
• Digestion in the stomach

  1. Stomach lining secretes gastric juice containing the enzyme pepsin

  2. Pepsin breaks down proteins into polypeptides

  3. Gastric juice also contains dilute hydrochloric acid to maintain acidic pH

  4. Stomach is a muscular sack that churns the food
• Rennin


  An enzyme found in the stomach of mammals that drink milk, which breaks down milk proteins
• Digestion in the small intestine

  Stomach turns food into a liquid called CHYME
• Digestion in the DUODENUM & JEJUNUM

  1. Duodenum receives bile from the liver

  2. Duodenum receives pancreatic juices from the pancreas

  3. Bile emulsifies fats (causes fats to clump together creating a large surface area for digestion by pancreatic lipase)
• Pancreatic juices


  • Contain pancreatic amylase (breaks down starch into maltose)
  • Contain trypsin (breaks down proteins into polypeptides and then amino acids)
  • Contain pancreatic lipase (breaks down fats into fatty acids)
• Digestion in the ILEUM

  1. Intestinal walls secrete intestinal juice

  2. Maltase breaks down maltose into glucose

  3. Sucrase breaks down sucrose into glucose and fructose

  4. Lactase breaks down lactose into glucose and galactose

  5. Peptidase (Crepsin) breaks down polypeptides into amino acids
• Petiole: connects the leaf to the stem of the plant
• Lamina: responsible for the manufacturing of food
• Midrib/Main Vein: transports water, minerals and manufactured food (along with the veins) and keeps the Lamina flat and exposed to sunlight
• Apex: guides excess water down to the soil close to the roots
• Waxy Cuticle: allows for easy absorption of sunlight and prevention of excessive water loss
• Upper Epidermis: allows sunlight to easily penetrate to the photosynthetic layer below
• Lower Epidermis: allows for carbon dioxide and oxygen to diffuse in and out
• Palisade Mesophyll: main photosynthetic layer of the leaf
• Spongy Mesophyll: allows for easy diffusion of water vapour, carbon dioxide and oxygen
• Vascular Tissue: Xylem(transports water and minerals)

  Phloem(transports food)