Biology

• What do plants need to survive?

  • nutrients
  • sun
  • water
  • CO2
  • oxygen
• What do animals need to survive?

  • food
  • mate
  • habitat/shelter
  • water
  • oxygen
• Intraspecific competition = competition between members of the same species for resources, food, mates, territory
• Interspecific competition = competition between individuals of different species for resources, like hyenas and lions fighting over a kill
• Behavioural = changes to their behaviour
• Morphological = changes to the body
• Invasive species = animals or plants that have been introduced either deliberately or accidentally into areas which they do not naturally occur
• Distribution = where can we find certain species of organisms in a habitat?
• Abundance = how much is present
• Qualatative = working with words
• Quantative = working with numbers
• • A bigger sample means that results are more accurate
• Sampling = size of area and how many quadrants fit into it
• How many chromosones are there in a diploid Human cell?

  • 46
• Haploid cell = sex cell (gamete)
• Diploid cell = regular human cells
• 1 division in mitosis
• Why is mitosis needed?

  • to replace and repair the cells that die and help you grow
• Nucleus = holds all genetic information of the cell, controls cell activities
• Mitosis

  • 1 division
  • happens with diplois
  • genetically similar
  • 2 daughter cells are formed
  • Daughyer cells have full set of chromosomes (46 in humans)
  • no generic variation
• meiosis

  • 2 divisions
  • happens with haploids
  • genetically different
  • 4 daughter cells formed
  • daughter cells have halve set of chromosomes
  • only in sex organs to make gametes
  • genetic variation
• Stem cell = undifferentiated cell that you can adapt so that it can do different jobs
• Gene = a specific code of DNA that codes for a specific protein
• Stem cells are found in adults and plants
• Embryo = can turn into any type of stem cell
• ASC (adult stem cell)

  • less efficient, has your DNA in it
  • can be painful (recovery 6-8 weeks)
  • cannot turn into most cells, only blood and tissue
• IVF

  • Takes sperm + egg, leaves them for 5-10 days
  • fertilises and puts embryo back into women
  • can be frozen or given to science
• Allelle = a different form of gene that codes for a different version of characteristic
• Heterozygous = letters are different
• Homozygous = letters are the same
• What are the uses of DNA fingerprinting?

  • determine a child’s paternity (dad)
  • to determine a familial connection
  • in criminal cases
• Electrophoresis = method of splitting up DNA
• How does DNA profiling work?

  • only 0.1% of DNA differs from one person to the next. The differences are used to generate a DNA profile ( from body tissues I.e. bone)
  • enzymes are used to cut specific sequences of DNA
  • sequences arranged in order of length using electrophoresis
  • labelled so that they show up when photographed
• Describe the structure and function of DNA

  • DNA is madd up of strands which form a double helix
  • each strand has 4 bases, adenine, hymine are complementary and guanine, cytosine are complementary
  • structure of DNA has a sugar phosphate backbone
  • 4 bases are used to create essential protein that the body needs
  • 3 bases, or triple code for specific amino acids.
  • amino acids codes for proteins in the body and photosynthesis forms human genetic functions
• Resolution = lowest possible value with your resilts
• Mutation = a random change in the genetic code. can happen if something goes wrong in mitosis. Base codes are different
• Triplet code = 3 base code for a specific amino acid. amino acid join together to make a certain protein
• Genotype = DNA of the code
• Who was Mendel?

  • a gardener who say you can have tall or short pea plants
  • wanted to see if he could change the traits
  • bred short + tall for medium height
  • did 1000’s of times and kept note of findings
• What is survival of the fittest? (Darwains evolution)

  1. individual organisms within a particular species may show a wide range of phenotype and generic variation
  2. individuals with characteristics most suited to the environment are more likely to survive and breed
  3. The alleles that have enabled these individuals to survive are then passed on to the next generation