moon 3 Flashcards
do loss of function mutated alleles always affect viability?
no, for example in the mendel experiment, the white flower has a loss of function allele: loss of function mutation of the gene required for pigment production that does not affect viability
the genes involved in purple pigment production are haplosufficient which is why they’re dominant
how are chromosomes in an organism?
Chromosomes, like Mendel’s “elements”, come in matched (homologous) pairs in an organism.
what happens to homologous chromosome pairs during meiosis?
The members of a homologous pair separate during meiosis, so each sperm or egg receives just one member.
explain this statement: “The members of different chromosome pairs are sorted into gametes independently of one another in meiosis, just like the alleles of different genes in Mendel’s”
during meiosis, the way one homologous pair separates into gametes does not affect how other pairs separate.
what are the principle of the chromosome theory of inheritance?
-Chromosomes, like Mendel’s “elements”, come in matched (homologous) pairs in an organism.
-The members of a homologous pair separate during meiosis, so each sperm or egg receives just one member.
-The members of different chromosome pairs are sorted into gametes independently of one another in meiosis, just like the alleles of different genes in Mendel’s
who was skeptical about mendel’s chromosome theory of inheritance?
thomas morgan hunt
what did thomas morgan hunt work with?
did genetic tests on drosophila, by observing the white eyed ones vs the red eyed ones
which allele is dominant in morgan’s experiments?
red eyes
what is the F1 of Morgan’s experiment?
what is the mendelian prediction of Morgan’s monohybrid cross?
what is the actual result of the F1 monohybrid cross in morgan’s experiment?
what was morgan’s second experiment?
what is the explanation for Morgan’s experiment results?
in Drosophila, a lot of genes on chromosome X, therefore during meiosis, transfer of genes linked to sex
explain Morgan’s experiment 1
explain Morgan’s experiment 2
how can we analyze human genetics in a mendelian way?
by using pedigrees
what is a monogenic phenotype?
phenotype affected by a single gene
how can we determine if a trait/phenotype/disease is autosomal or sex-linked?
if autosomal: gender has no effect on if get disease or not
if sex-linked: either X-linked or Y-linked
how could we see that a trait is X linked?
if it is X-linked, there will be significantly more males than females affected, because men only have one X chromosome, so they only need one mutant x to express the phenotype
how could we see that a trait is Y linked?
can only transmit male to male
how do we differentiate a rare trait from a common trait on a pedigree?
if people marrying into affected family are also carriers, assume its common
