lab 10 - heredity and genetics ii Flashcards
how do sex-linked traits differ from autosomal traits?
sex-linked traits are located on sex chromosomes ( or Y), while autosomal traits are found on non-sex chromosomes
why can males express recessive X-linked traits more easily?
males only have one X chromosomes, so there’s no second allele to mask the recessive trait
what physical feature distinguishes male Drosophila flies from females?
males have darker bands on the top of their abdomen compared to females
what tool is used to compare observed and expected phenotypic data?
the chi square (x^2) test
what does the chi-square test determine?
whether the difference between observed and expected data is statistically significant
define “wildtype” in Drosophila genetics
most common phenotype in a population (red eyes)
what does a p-value less than 0.5 indicate?
the null hypothesis should be rejected; the difference is statistically significant
how do you identify female Drosophila?
females have lighter, pointed abdomens with more visible bands
what is the purpose of this lab?
to investigate if eye colour is a sex-linked trait in Drosophila
what is a chi-square test?
a test to compare observed vs expected data for significance
what is the independent variable?
parental genotype
what is the dependent variable?
offspring
what is the expected ratio for a sex-linked Drosophila cross?
1:1:1:1
