Exam 2 part 2 Flashcards
Genetic significance of meiosis
each gamete at the end carries only one copy of each chromosome
Homologous chromosomes end up at one pole or the other at random
Chromosomes don’t influence each other’s segregation
crossing over between maternal and paternal homologs during meiosis I creates new allele combinations
Law of Segregation
comes from monohybrid cross
homologous chromosomes end up at one pole or the other at random
recessive traits are masked in F1 generation and reappear in specific proportion in F2 gen
2 alleles segregate during formation of gametes in anaphase I
Mendel’s monohybrid cross
gave rise to law of segregation
cross between true-breeding strains of pease with alternative forms of a single trait
peas had homozygous filial genotypes
Dominance
masking of traits by gain or loss of function mutations
How do you know if an individual with a dominant phenotype is homozygous or heterozygous?
Testcross
Testcross
cross of unknow genotype possing the dominant phenotype with a known homozygous recesive individual (tester)
Then analyze progeny
Law of independent assortment
came from dihybrid cross
chromosomes don’t influence each other’s segregation
the two causative genes for two pairs of traits assort independently of one another
pairs of alleles for genes on different chromosomes segregate independently in the formation of gametes
The product rule
the probability of 1 independent events occuring simultaneously is the product of their individual probabilities
the sum rule
the probability of either one of several independent, mutally exculsive event is the sum of their individual probabilities
Binomial theorem
the probability that a situation will occur when there are multiple ways to get a combination
EQUATION
Human diseases that follow Mendelian inheritance
Huntington's Albinism PKU Sickle Cell etc
Pedigree
analysis of an inherited disease that follows a family
