genotype/phenotype - mutations

Question 1

what is meant by autosomal dominant?

Answer 1

heterozygotes affected (Hh)

effects genders equally

infected individual have 50% passing to offspring

every effected individual has one affected parent

disease can’t skip generations

Question 2

what is meant by autosomal recessive?

Answer 2

heterozygotes unaffected, must be homozygous (hh)

equals effect b/w genders

two heterozygotes have a 25% of passing to offspring

two homozygotes will have 100% of passing down

skips generations - carriers

Question 3

what is X-linked recessive inheritance?

Answer 3

more common in males

hemizygous males (X^aY) and homozygous females (X^a X^a) affected

heterozygous female has 50% to pass down to sons

affected males do not pass to male offspring

Question 4

what is linkage?

Answer 4

genes likely to be inherited together b/c they are physically close on the same chromosome

Question 5

what is a mutation?

Answer 5

permanent alteration to DNA sequence

Question 6

different classifications of mutations?

Answer 6

base substitution - change of a single nucleotide to one of the other three

deletion - removal of sequence

insertion - addition of sequences

rearrangement - rearrangement of sequences

Question 7

what is a point mutation?

Answer 7

Single base substitutions

transition - b/w same purine to purine etc
transversion - b/w purine and pyrimidine

missense - base substitution, cause diff AAs

nonsense - base substitution results in stop codon

silent - no change in AAs

Question 8

types of DNA repair mutations?

Answer 8

mismatch repair - cells that have mutations in genes when involved in DNA correction

excision repair - remove damage nucleotides

Question 9

what is a double strand break repair?

Answer 9

both DNA strands are broken, cause chromosomes to rearrange

failure to repair can cause diseases