Topic 1

Question 1

what is molecular genetics?

Answer 1

study of DNA and RNA structure, function, and molecular control of gene expression

Question 2

what is evolutionary/population genetics?

Answer 2

interaction of genes and gene pools and the environment

Question 3

what is classical genetics?

Answer 3

Deals with inheritance of traits; “Transmission genetics”

Question 4

what is a gene?

Answer 4

a hereditary unit of information

Question 5

what is a gene locus?

Answer 5

the position of a gene on the chromosome

Question 6

what is an allele?

Answer 6

one of two (or more) versions of a gene that differs in sequence and exists at the same loci

Question 7

what is a genotype?

Answer 7

the combinations of alleles for any gene

Question 8

what is a phenotype?

Answer 8

the observable characteristics, as determined by the geneotype

Question 9

what is wildtype?

Answer 9

The most prevalent phenotype in a
population under natural conditions

Question 10

what is a mutant?

Answer 10

a deviation to the wild-type phenotype as a result from an allelic change in DNA sequence

Question 11

what is dominant?

Answer 11

The phenotype observed in heterozygous
individuals (i.e. genotype includes both allele variants)

Question 12

what is recessive?

Answer 12

The phenotype observed only in individuals
that are homozygous for the recessive allele variant

Question 13

what is dominance determined by?

Answer 13

a protein produced by each allele

Question 14

when is a wildtype phenotype produced?

Answer 14

when an organism has two copies of the
wild-type allele, or when one copy is sufficient to meet the protein
requirements

Question 15

what does it mean when a mutant allele is loss of function?

Answer 15

significant decrease or complete loss of functional gene product

Question 16

what does it mean when a mutant allele is gain of function?

Answer 16

gene product acquires a new function or expression increased above wild-type activity

Question 17

how can a mutation be dominant while also being loss of function?

Answer 17

Because the wildtype produces protein however it isnt sufficient to meet the protein requirement and the muatation isn’t producing any protein

Question 18

what is it called when a mutant is loss of function but dominant?

Answer 18

dominant negative mutation

Question 19

what does incomplete domiance suggest for molecular basis of dominance?

Answer 19

heterozygous individuals display intermediate phenotypes between
either homozygous type

Question 20

what is codominance for molecular basis of dominance?

Answer 20

there is detectable expression of both alleles in the heterozygotes

Question 21

what is recessiveness?

Answer 21

when a mutation is functionally haplosufficient—> the mutated allele is the recessive allele

Question 22

what does haplosufficient mean?

Answer 22

the mutant is recessive when half of the alleles is sufficient to meet the wildtype phenotype requirements

Question 23

what is dominance (complex)?

Answer 23

the mutated allele is the dominant allele when a heterozygote is haploinsufficient

Question 24

what does haploinsufficient mean?

Answer 24

the mutant allele is dominant because the wildtype allele cannot provide enough product to achieve the wiltype phenotype

Question 25

what does a single letter mean in nomenclature?

Answer 25

denotes mutant phenotype or recessive

Question 26

what does upper case mean in nomenclature?

Answer 26

denotes dominant allele

Question 27

what does lower case mean in nomenclature?

Answer 27

denotes recessive allele

Question 28

what do slashes mean in nomenclature?

Answer 28

indicates alleles for genes are on homologous chromosomes

Question 29

what do semicolons mean in nomenclature

Answer 29

indicate genes on non homologous chromosomes

Question 30

why is nomenclature important?

Answer 30

it conveys the relationship between alleles and chromosomes, between parents and daughters

Question 31

what is equal segregation?

Answer 31

half of gametes carry one member of a gene pair, half carry the other member

Question 32

what is another name for equal segregation?

Answer 32

mendels first law

Question 33

what does non autosomes mean?

Answer 33

sex chromosomes

Question 34

what happens if one sex does not have a pair of similar sex chromosomes?

Answer 34

the other does

Question 35

what does homogametic mean?

Answer 35

matching pair of sex chromosomes (XX)?

Question 36

what is a propositus?

Answer 36

the first member of a family who is identified with the mutant type

Question 36

what does heterogametic mean?

Answer 36

no matching pair of sex chromosomes (XY)

Question 36

what does polymorphisms mean?

Answer 36

carriers are common in population

Question 36

what does rare disease mean?

Answer 36

carriers are not common

Question 37

why do we assume new individuals are introduced when we hear rare disease?

Answer 37

because if the disease was present through out the family it probably would have shown up, someone else coming into family would disrupt cross patterns and give new phenotypes

Question 37

what are the traits of autosomal recessive pedigrees?

Answer 37

1. disease shows up from unaffected parents
2. all children will have it if both parents have it
3. males and females have equal chance of getting it

Question 38

what are the traits of autosomal dominant pedigrees?

Answer 38

1. doesn’t skip generations
2. sex doesn’t matter, equal probablilty
3. Two affected parents can produce unaffected children, but two unaffected parents can never have affected children

Question 39

what are the traits of X-linked recessive disease?

Answer 39

1. more males than females affected
2. if father is affected none of his offspring will be
3. all males offspring of an affected female will be affected

Question 40

what are the traits of x-linked dominant disease?

Answer 40

1. all daughters of an affected male will be affected
2. only need one copy to be affected
3. an affected female will transmit to male and female equally