BIO SCI 93 Lecture Notes - Lecture 22: Thomas Hunt Morgan, Allosome, Centimorgan
2 Jan 2018
School
Department
Course
40
BIO SCI 93 Full Course Notes
Verified Note
40 documents
Document Summary
1875-1890s- meiosis and mitosis worked out via microscopy and cytology. Nobel prize for discoveries concerning role of chromosomes in heredity. White eyed trait only in males- eye color linked to sex!! (gene located on x chromosome- unique inheritance patterns) Genes located on the same chromosome that tend be inherited together. Percentage of recombinant offspring (recombinant frequency) related to distance between linked genes. Linkage maps show the relative locations of genes along a chromosome. Percentages may not add up due to crossing over! Sex of offspring in mammals depends on whether sperm carries x or y chromosome. Carry genes for many characters unrelated to sex (follows same patterns of inheritance as white eye locus in drosophila) One shut off; methylated and condenses into barr body attaching to nuclear envelope. Genes reactivated in ovarian cells that produce ova. Half of cells will express one allele while the other half expresses the other allele. Ex. normal skin & skin that lacks sweat glands.
