exam qs (diversity)

• what is the effect of the pateau syndrome on the chromosomes of this female?

  three of chromosome 13
• describe how the change in chromosome number was produced

  in meiosis homologus chromosomes do not seperate
• explain why all cells in the body will have this mutation

  all the cells are derived from a single cell

  which divides by mitosis to produce genetically identical cells with the same dna
• the biologists measured the max diameter of each of the shrimos eye

  explain why they used max diameter

  so the results can be compared
• adaptations such as smaller eyes and a greater use of organs

  does the data support this?

  eye diameter is smaller and the antenna is longer

  the antenna detects touch

  but the data only refers to shrimps and not all animals
• figure 2 shows mean values explain how standard deviation of these values can help interpret data

  standard deviation gives a measure of variation

  more standard deviations overlap the less likely the differences are real
• diploid number of organisms

  6
• in figure 1 what is happening

  chromosomes are arranged in homologus pairs

  crossing over is occuring where they share genetic information
• what is happening in figure 2?

  the seperation of homologus chromosomes pulled at the centromere by spindle fibres
• what is an allele?

  a different form of a gene
• explain dna replication

  hydrogen bonds are broken

  bases are then exposed on the template strand

  nucleotides line up by complimentary base pairing

  and join by phosphodiester bonds catalysed by dna polymerase which holds the bases together

  this is semi conservative replication
• explain why a mutation involving deletion of a base will be greater than substitution

  deletion - causes a change in base sequence and causes a frame shift

  this changes the sequence of amino acids produced

  substitution - alters the one codon triplet

  -but genetic code has a degenerate nature so the same amino acid may still be produced
• what is the point of boiling agar?

  to rid of any other possible bacteria on agar plate
• why do you need to transfer the same volume of liquid onto the agar plate?

  • ensures consistent conditions for bacterial growth and allows for a comparison between the number of bacteria produced
• describe how you could obtain more accurate resultsof propan-2-ol to stop the growth of this species

  repeat at 10 and 15 units
• type of selection and why

  directional selection - one extreme is favoured
• explain the purpose of tank b

  act as a control to show the effect of no selection
• evaluate the nets

  not - sea nets reduces the mean mass of fish because large fish are removed

  but : information is only on one species

  there is no statistical test and the size of the tank may affect the growth of the fish