LG

• Water cycle


  The processes of evaporation, condensation, precipitation, and runoff
• Evaporation


  Water changes from a liquid state to a gas (vapour)
• Transpiration


  Evaporative water loss through plant pores (stomata)
• Condensation


  Water (vapour) molecules rejoin hydrogen bonds to form liquid
• Precipitation


  As condensation intensifies, water droplets become large enough to fall
• Runoff


  Draining away of water from the surface of an area of land
• Reservoirs


  Places where water is "stored", or where it stays for some period of time
• Factors that influence the rate of evaporation

  • Temperature
  • Humidity
  • Wind Speed
  • Surface Area
  • Air Pressure
  • Solar Radiation
• Albedo effect


  The reflectivity of a surface, the extent to which an object reflects light from the sun
• Latitude


  Regions near the equator have highest and most consistent level of solar isolation
• Hemisphere


  Northern hemisphere receives maximum isolation in March – September, Southern hemisphere receives max isolation between September – March
• DNA


  Double helix = two long strands of nucleotides wound around in a spiral ladder pattern
• Nucleotide


  Sugar + phosphate + base
• DNA Backbone


  Sugar + phosphate
• Genetic code


  Sequence of bases (A, T, C and G)
• Complementary base pairs


  1. T and C-G
• Role of DNA


  Contains the genetic instructions for an organism, with each DNA molecule containing thousands of genes
• Genes


  Specific DNA sequences that provide the instructions for making proteins
• Proteins


  Complex molecules that carry out most of the work in cells and determine an organism's characteristics
• DNA, genes and chromosomes

  Gene is a segment of DNA, chromosome is a long strand of coiled up DNA, each chromosome carries the code for a couple thousand genes
• Mitosis


  Cell division process that ensures each new cell produced is genetically identical to the parent cell, allowing for growth, repair, and asexual reproduction
• Meiosis


  Specialized cell division that produces haploid gametes (sperm and egg cells) from diploid cells, leading to genetic recombination and halving of chromosome number
• Fertilization


  The process by which a sperm cell fuses with an egg cell to form a zygote, combining genetic material from both parents
• Genetic terms


  • Dominant
  • Recessive
  • Phenotype
  • Genotype
  • Allele
  • Genes
  • Heterozygous
  • Homozygous
• Modes of inheritance


  • Complete dominance
  • Incomplete dominance
  • Codominance
  • Sex-linked genes
• Relationship between genetic characteristics and survival/reproduction


  Genetic characteristics influence an organism's ability to survive and reproduce in its environment
• Natural selection


  1. Variation

  2. Overproduction

  3. Competition for survival

  4. Selection (survival of the fittest)

  5. Reproduction

  6. Inheritance of variation
• Natural selection


  • Variation
  • Overproduction
  • Competition for survival
  • Selection (survival of the fittest)
  • Reproduction
  • Inheritance of variation
• Variation


  Genetic variation: Mutations, genetic recombination, and other sources of genetic diversity within a population
• Importance of variation


  Provides the raw material for natural selection
• Overproduction


  Excess offspring: Organisms produce more offspring than can survive to adulthood
• Importance of overproduction


  Leads to a struggle for survival as resources are limited
• Competition for survival


  Resource limitation: Individuals compete for limited resources such as food, water, shelter, and mates
• Importance of competition for survival

  Only some individuals will obtain enough resources to survive and reproduce
• Selection (survival of the fittest)

  1. Adaptation: Individuals with traits better suited to their environment are more likely to survive and reproduce

  2. Fitness: "Fittest" refers to those best adapted to the environment, not necessarily the strongest
• Importance of selection


  Advantageous traits become more common in the population over generations
• Reproduction


  Successful reproduction: Individuals that survive and reproduce pass their advantageous traits to their offspring
• Importance of reproduction


  Traits that confer survival advantages are propagated through the population
• Inheritance of variation


  Genetic transmission: Offspring inherit traits from their parents
• Importance of inheritance of variation

  Ensures that beneficial traits are passed on to the next generation, continuing the cycle of natural selection