Biology

• Contraception


  • Preventing fertilisation
  • Non-hormonal methods (condoms, diaphragm, spermicide, rhythm method, surgery)
  • Hormonal methods (birth control pill, IUD, implants, patches, injections)
• Functions of bile
• Evaluating different contraceptives
• Habitat


  The place where an organism lives
• Ecosystem


  The habitat, the community, and the conditions
• Ecology


  Studying the living things in different habitats and how they interact
• Community


  All the different types of living things in a habitat
• Population


  The number of one type of living thing
• Adaptation


  • A feature or characteristic that helps an organism survive in a habitat
  • Features are controlled by an organism's genes
  • They do not appear during the life of the organism
• Offspring which are most suited to the habitat

  Survive better and have more young, passing on their genes
• Adaptations for living in a desert

  • Camel can survive long periods without water due to hump
  • Thick fur for insulation
  • Light coloured fur reflects heat
  • Wide feet to sink less into sand
  • Leaves modified into spines to prevent being eaten
• Competition


  Animals and plants compete for limited resources like food, territory, mates, shelter, sunlight, water
• Types of organisms


  • Predator
  • Prey
  • Carnivore
  • Herbivore
  • Scavenger
  • Parasite
  • Pollinator
• Biotic factors


  All the living influences in an ecosystem
• Abiotic factors


  All the non-living influences on an ecosystem
• Converting units: 1 cm = 10 mm, 1 mm = 1000 μm, 1 μm = 1000 nm, 1 nm = 1000 pm
• Interdependence: organisms rely on other organisms for food, pollination, seed dispersal etc.
• Factors affecting whether organisms can live in a habitat

  • Amount of food
  • Number of predators
  • Presence of disease
• Whether an organism can live in a certain habitat, and in what numbers, depends on the influence of biotic and abiotic factors
• Factors determining the distribution of an organism

  • Biotic factors
  • Abiotic factors
• Distribution of clouded leopards

  • Lives in the Himalayan foothills (SE Asia)
• Distribution of spider monkeys

  • Found in tropical rainforests, mexico etc...
  • Population is around 250 individuals