Inheritance, Variation and Evolution

• Does asexual reproduction involve fusion of gametes?

  no
• Does asexual reproduction involve mitosis?

  yes
• What does sexual reproduction involve?

  fusion of male and female gametes
• What are the sex cells in plants?

  pollen and egg cells
• Sexual reproduction produces….

  variation in offspring
• The formation of gametes involves…

  meiosis
• What happens during meiosis?

  1. copies of genetic information made
  2. cell divides twice to form 4 gametes
  3. all gametes genetically different from each other
• What are some advantages of sexual reproduction?

  • Variation
  • changes in environment hold less threat due to variation (some organisms will survive). - Selective breeding
• What are some advantages of asexual reproduction?

  -only one parent needed

  -energy and time efficient

  -faster

  -identical offspring
• What is the genetic material in nucleus of a cell made of?

  chemical called DNA
• Where is DNA contained?

  chromosomes
• What is a gene?

  part of a chromosome, small section of DNA
• What do genes code for?

  particular sequence of amino acids to make a specific protein
• What is a genome?

  all genetic material in an organism
• What is DNA?

  a polymer made of nucleotides
• What does a nucleotide consist of?

  sugar

  phosphate

  a base
• What are the 4 bases?

  C, G and A, T
• What hold the two strands of DNA together?

  attraction between bases
• How many baes is the code for one amino acid?

  3
• What is a mutation?

  change in DNA structure
• Do all parts of DNA code for proteins?

  no
• What can non-coding parts of DNA do to genes?

  switch them on/off so then can/cannot make specific proteins
• What can mutations cause?

  change in protein shape
• What is polydactyly?

  Genetic disorder involving having extra fingers or toes
• Is polydactyly caused by a dominant or recessive allele?

  dominant
• Is cystic fibrosis caused by a dominant or recessive allele?

  recessive allele
• What is cystic fibrosis?

  Genetic disorder of cell membranes
• What does cystic fibrosis do?

  causes build up of mucus in lungs
• What is the difference between sex chromosomes in male and female?

  female- sex chromosomes identical (XX)

  male- not identical ( XY )
• How many pairs of chromosomes out of the 23 determine sex?

  1
• What is the genotype?

  combination of alleles an individual has for a particular gene
• What is the phenotype?

  physical expression of the genotype (e.g. characterisitic)
• What 2 things are alleles?

  dominant or recessive
• What does homozygous mean?

  two alleles are the same
• What is heterozygous?

  two alleles are different
• What is variation?

  differences in characterisitcs of individuals
• What can variation be caused by?

  genetics

  environment

  combination of above
• Which type of reproduction variation?

  sexual
• Do most mutations affect the phenotype?

  no
• What is evolution?

  gradual change in a group of organisms over a long period of time