mutation

Question 1

define mutation

Answer 1

any alteration to the genetic material (DNA or RNA) that produces a heritable change in the nucleotide sequence

Question 2

what ISN’T mutation
(common misconceptions)

Answer 2

• chemical damage to DNA that isn’t inherited or chemical modifications of nucleotides associated with temp changes in gene function
• genetic recombination

Question 3

what is genetic recombination

Answer 3

a process that re assorts genes between homologous chromosome pairs

Question 4

what are chromosomal aberrations

Answer 4

deletions
duplications
insertions
inversions

Question 5

what are genome rearrangements

Answer 5

re distribution of genetic material between non homologous chromosomes

• arises from chromosome breakage

Question 6

what is aneuploidy

Answer 6

changes in chromosome number

usually arise from mistakes in chromosome segregation at cell division

• eg trisomy of chromosome 21 (downs syndrome )

Question 7

what are point mutations

Answer 7

single nucleotide changes:
- base substitution
- loss or gain of a single nucleotide

Question 8

what is translocation or transposition (DNA)

Answer 8

movement of a piece of DNA from one location to another

Question 9

base pair substitutions definition

Answer 9

a mutation that results in the substitution of one base pair for a different base pair

Question 10

how can point mutations be classified

Answer 10

• silent, missense, or nonsense
  due to base substitution
• frameshift , alteration of reading frame
  due to insertion/deletion of a nucleotide

Question 11

effect of point mutations on the protein

Answer 11

no effect
- samesense (DNA polymorphism )
- missense (protein polymorphism)
- change of function
missense, small deletions \
-loss of function
missense, nonsense and frameshift

Question 12

what does mutation prevent in diploids

Answer 12

gene product synthesis

eg a deletion

Question 13

how does gene mutation affect haploid organisms

Answer 13

they only have one copy of each gene and therefore a mutation that affects gene function alters the phenotype

Question 14

wild type hz mutant genotype

Answer 14

id the mutant protein has little or no activity and half the wild type protein is enough

the mutation is recessive

Question 15

mutant hz mutant genotype

Answer 15

if the mutant protein has an altered function that displaces the wild type protein

mutation is dominant

Question 16

intermediate hz mutant genotype

Answer 16

if both wild type and mutant proteins function, but differently
wild type and mutant genes are codominant

Question 17

what is a heritable change to DNA

Answer 17

a mutation