Chapter 3 Flashcards
(20 cards)
If R and Y segregate independently of one another, what gamete freqency do we expect?
1/4
If R and Y segregate independently of one another, what is its phenotypic ratio
9:3:3:1
the product rule predicts a -
9:3:3:1 ratio from two independent 3:1 ratio
-indicates that the two genes are independent of one another (;)
what does / mean
indicates alleles are on a homologous pair
what is the test cross progeny ratio
1:1:1:1
monohybrid self-cross Yy x Yy =
3:1 phenotypic ratio
monohybrid test cross Yy x yy =
1:1 phenotypic ratio
mendels first law of equal segregation
during gamete formation, members of a gene pair segregate equally
monohyrbid self-cross/ test-cross
mendels second law of independent assortment
during gamete formation, the segregation of alleles of one gene is independent of the segregation of alleles of another gene
-4 possible gametes
-Y has equal prob of combining with R or r
dihybrid self-cross/test cross
dihybrid self-cross Y/y;R/r x Y/y;R/r results
9:3:3:1 phenotypic ratio
dihybrid test-cross Y/y;R/r x y/y;y/r results
1:1:1:1 phenotypic ratio
in the cross Aa;Bb;Cc;Dd;Ee x Aa;bb;CC;dd;Ee, how many genotypes are possible
3x2x2x2x3 = 72
Chi-Square (X2) Test allows us to-
determine if progeny fit expected ratios
what is a Chi-square test
a statistical test to determine if the observed results are significantly different from the expected
how to calculate X2 value
(observed-expected)2/ expected
what is df
n (number of classes) -1
if X2 is smaller than critical value than
p is bigger than 0.05
= fail to reject the null hypothesis
If X2 is bigger then critical value than
p is smaller than 0.05
= reject the null hypothesis
polygenic inheritance
traits that show continous variation- quantitative phenotypes, distribution in a pop is bell-shaped
cytoplasmic inheritance
inheritance of traits associated with non-nuclear genome
phenotype of offspring depends on genotype of maternal (egg) cytoplasm
