Biology

• What is sexual reproduction?


  genetic information from 2 organisms (parents) is combined to produce offspring
• What is Asexual reproduction?


  Only one parent. Offspring is genetically identicle to the parents (clone)
• In sexual reproduction there is....?

  variation
• In asexual reproduction there is...?

  no variation
• advantages of sexual reproduction:

  variation in offspring, increases chance of a species surviving a change in the environment
• advantages of asexual reproduction:

  only needs one parent, requires less energy, faster then sexual reproduction
• how is DNA arranged

  long strands called choromosomes
• mitosis


  2 identical daughter cells
• meiosis


  4 identical daughter cells
• gene


  a section of DNA that codes for a protein/ characteristics
• where does meiosis occur

  testes (male) ovaries (female)
• what does DNA stand for?


  Deoxyribonucleic acid
• What is a genome?


  A genome is the complete set of genetic material in an organism.
• The DNA is held in the...?

  nucleus
• Allele


  different versions of the same gene
• Homozygous


  both alleles are the same
• Hetrozygous


  the alleles are different
• Dominant allele


  will be expressed if present
• recessive allele


  only expressed if dominant allele is absent
• genotype


  combination of alleles that you have
• phenotype


  what characteristics you have
• How many chromosomes do we have?

  23 pairs
• Males chromosomes are


  xy chromosomes
• females chromosomes are 


  xx chromosomes
• genetic variation


  the combining of genes from two parents causes genetic variation - no two of the species are genetically identical (except identical twins)
• environmental variation 


  tattoos, suntan, scars, language, hairstyle, dyed hair
• natural selection


  a mechanism of evolution
• Habitat


  where organisms live
• populations


  all the organisms of one species living in a habitat
• community


  the population of different species living in a habitat
• abiotic factors


  non-living factors of the environment
• biotic factors


  living factors of the environment
• ecosystem


  the interaction of a community of living organisms
• interdependence 


  the dependence of two or more organisms on eachother
• quadrats


  used to make counting populations of species easier
• biomass


  the mass of materials in living organisms
• wet biomass


  weight of the living material
• dry biomass


  weight of the living material after its been dried
• what happens during prophase

  the chromosomes condense and thicken. line up homologous pairs. crossing over
• what happens during metaphase


  the chromosomes line up in the middle of the cell