inheritance and dna

• what is dna

  chemical all genetic material made from that contains coded information. polymer that has two strands coiled together in double helix
• what determines inherited characteristics

  dna
• what is a chromosome

  coiled up lengths of dna
• what is a gene

  small section of dna on chromosomes
• what do genes code for

  particular sequence of amino acids which make specific protein
• what does dna determine

  proteins cell produces which determine type of cell it is
• what is a genome?

  entire set of genetic material in organism
• why is understanding genome important

  allow identify genes that linked to type of disease. understanding and treatment of inherited disorders. use in tracing human migrations patterns in past ie if go Africa have slightly different genome
• what are repeating units called in dna?

  nucleotides
• what are nucleotides made from

  sugar. phosphate group. 1 base
• what do the sugar and phosphate groups do

  form a backbone to dna strands
• what happens when the sugar and phosphate groups alternate

  a, t, c, or g bases join to each sugar
• what does each base link to

  opposite strand in helix
• what is complementary base pairing

  a always match up t c always match up g
• what determines order of amino acids in protein

  order of bases
• what do parts of dna that do not code for proteins do

  switch genes on and off control whether gene expressed(used make protein)
• what happens during protein synthesis

  transcription. dna unwinds. during transcription mrna made. mrna move from nucleus to cytoplasm to ribosomes. translation happen in ribosomes. mrna bind to ribsomes carrier molecules bring specific amino acids. amino acids join form protein. protein fold for specific function
• what are the three functions of proteins

  enzymes. hormones. structural proteins
• what do structural proteins do

  physically strong that strengthen things e.g. collagen strengthen connecting tissues
• what is a mutation

  random change in organism dna
• what is the chance of mutation increased by

  exposure to certain substances of types of radiation
• what do mutations do

  change sequence of dna bases produce genetic variant
• what happens if protein shape change

  enzyme active site no longer bind to it. structural proteins lose strength so not provide support.
• what are insertions

  new base inserted into dna base sequence but shouldn't be there. insertions changes way three based read so code for different amino acids. can change more than one amino cid because have knock on effect
• what are deletions

  when random base deleted from dna base sequence. change way base sequence read then knock on effects
• what are substitutions

  random base in dna changed to different base
• what is sexual reproduction

  where genetic information from farther and mother combined to produce genetically different offspring. have mixture of dna
• how does sexual reproduction happen

  by mother and father produce gametes
• how many chromosomes does a human gamete contain

  23 which is half number of cells of normal cell
• what is it called when cell contains half genetic information of cell

  haploid
• what is it called when cell contains same amount of chromosomes as cell

  diploid
• what do the sperm cell and the egg cell do to form cell with full number of chromosomes

  fuse together
• what is plants cells version of sperm and what is this type of reproduction

  pollen. sexual reproduction
• what is asexual reproduction

  when only one parent so offspring genetically identical to parent
• how does asexual reproduction happen by

  mitosis
• what are the offspring of asexual reproduction known as

  clones
• meiosis steps

  dna of cell duplicates before cell division. chromosomes line up in middle of cell in pairs. chromosomes pulled apart to opposite ends of cell. cell divides again. produces 4 non identical daughter cells (gametes)
• what does variation increase

  chance of species surviving a change in environment. have survival advantage
• what happens if organisms have variation

  more likely to breed successfully and pass genes needed for characteristics(natural selection)
• what is done to speed up natural selection

  individuals with desirable characteristics bred to produce offspring that have desirable characteristics. might increase food production because breed animals that produce lots meat