Reading 17/18 Flashcards
True or False: The sorting of alleles in new combinations (i.e. the independent assortment of alleles) is due to effects of recombination between those genetic loci (as Mendel observed)
-true
Who is Walter Sutton? What theory did he put forth in 1903?
-Columbia university grad student
-proposed chromosome theory of heredity
What is the ‘Chromosome Theory of Heredity’?
-implies alleles segregate into gametes because chromosomes segregate during meiosis
What is meant by the term ‘linkage group’? Do linked genes sort independently?
-set of genes at different loci on the same chromosome, instead of crossing over, they act as a single pair of genes
-no
Why are linked genes NOT expected to sort independently? Along these lines, are genes in very close proximity more or less likely to be linked?
-because they are usually inherited together on the same chromosome situated closely together
Why do you think that Mendel observed each of his traits did indeed sort independently?
-because traits are on the same chromosome, combinations are due to recombination between paternal and maternal genes
What did Bateson, Saunders, and Punnett observe in 1905?
-the parental allele in chromosome combination is observed more frequently
True or False: A testcross can be utilized to reveal the effects of linkage
-true
How would one perform a testcross? What is the significance of the utilizing a true-breeding homozygous recessive plant in a testcross?
-crossing a heterozygous with a homozygous recessive
-alleles from heterozygous parent will be observed in the cross, you can determine whether an individual is homozygous dominant or heterozygous
How do non-recombinant and recombinant gametes differ?
-non-recombinant gametes: crossing over does not occur
-recombinant gametes: crossing over occurs
