Biology Lecture 7: The Case of Mary Jane
Question: Recombination in prophase of Meiosis I creates sister cromatids that now carry different
alleles. When will “A” alleles separate from the “a” alleles into different cells?
B. Anaphase of Meiosis I
C. Anaphase of Meiosis II
Mary Jane needs new Kidneys! She is informed that two of her kids are not hers.
The doctors haven’t learned about DNA fingerprints in Mary Jane’s case...
Pedigrees show family relationships.
Females are indicated in circles, Squares indicate males. A vertical line indicates one
generation, and a horizontal line indicates a relationship.
Everyone has a normal karyotype, in the case of Mary Jane.
Chromosome specific stains result in different colours after UV illumination. Fluorescent
In interphase the DNA of a chromosome is sort of together and in the same area.
When the chromatin is much more condensed into chromosomes, then we can match them
up and arrange them into a standard display called a karyotype.
Mary Jane’s karyotype is normal.
Clicker Question: To make a karyotype, cells are photographed in metaphase. Which metaphase:
C. Meiosis II
Red blood cells display ABO blood type antigens.
Each person carries two alleles. Gene vs. Allele vs. Locus:
o Two different alleles of the