M6 C19 Genetics of living systems: PMT cellular control QP1 Flashcards
RNA polymerase and DNA polymerase are both enzymes. RNA polymerase is involved in the action of some control elements, whereas DNA polymerase is not. Describe and explain the difference between the functions of these two enzymes
RNA polymerase makes mRNA through transcription and uses one strand of DNA to form another.
DNA polymerase is used to replicate DNA and is semi-conservative. Replicates DNA before cell division
state what is meant by a homeobox gene
the homeotic gene contains the homeobox sequence that codes for homeodomain which binds to DNA in order to switch genes on or off and develop the body plan.
Homeobox genes show ‘astonishing similarity across widely different species of animal’. Explain why there has been very little change by mutation in these genes.
as these genes are very important and a mutation would have a large effect particularly on the body plan
Name another kingdom of organisms, other than animals, that have similar homeotic genes.
plant/fungi
What name would be given to a mutation that resulted in a change of the codon UUU to UUC?
neutral / silent / substitution
during which stage of meiosis does the separation of sister chromatids happen
anaphase II
during which stage of meiosis are chromosomes pulled to opposite sides
anaphase I
Discuss the possible effects that mutation can have on the structure and function of a protein.
can cause a change to the primary/secondary/tertiary structure of a protein.
protein could be shorter due to, deletion / stop codon OR longer due to, insertion / duplication
or protein could be unchanged due to, silent mutation / non-coding DNA altered
causing function to be better/worse or lost
Suggest two purposes of a plant collection in a modern botanic garden.
- for aesthetic value
- for conservation of rare species
- create a gene bank
- for teaching
what is the role of the polymer chain reaction PCR
to produce copies of DNA
what is the role of electrophoresis
to separate/ arrange DNA fragments according to size so that they can be read in order of bases
what is the role of restriction enzymes
to cut DNA into smaller fragments, to cut vectors
Suggest why a genome has to be fragmented before sequencing.
as the genome would be very large of not fragmented and therefor would take too long to sequence. Smaller fragments can be sequenced with greater accuracy
How does the phylogenetic approach to classifying species differ from the biological species concept?
the phylogenic approach to classification does not need to test for interbreeding whereas the biological species concept tests to see whether fertile offspring can be produced.the phylogenetic approach can be applied to organisms that reproduce asexually unlike the biological species concept
State three phenotypic traits (characteristics) that have been selected for in dairy cows.
- larger yield of milk
- high quality of milk
- effective immune system
