Lab 6 Flashcards
What are autosomes?
The remaining non-sex chromosomes in the nucleus
How is it that the male determines the sex of the offspring?
It determines which gamete (X or Y) fertilizes the female XX
If Y, then male
If X, then female
What is a karyotype?
A photograph of the chromosomes of an actively dividing cell
Shows number, shape, and size of chromosomes
The picture that shows the 23 sets of chromosomes in humans
What is Turner syndrome?
Where they’re missing a second X chromosome in females
Only have one X chromosome
Short stature
Non functioning ovaries
What is Down syndrome?
The 21 set of chromosomes has three chromosomes instead of 2
Moderate mental deficiency
Almond shaped eyes
What is kinefeller?
males that have an extra X chromosome along with a Y chromosome
So to X chromosomes and one Y chromosome
Men are sterile with small testes
Lack testosterone
Who are more likely to exhibit a sex linked recessive trait? Males or females
Males since they only carry one X chromosome capable of holding an allele where females carry two
What is Protan deficiency compare to Deutan deficiency in colour blindness?
Protan- caused by reduced amounts or a complete absence of red photoreceptors in the eye
Deutan- caused by reduced amounts or a complete absence of green photoreceptors in the eye
What are polygenic traits?
Phenotypic traits that involve contributions from the alleles of many genes at multiple locations along chromosomes
What are the three types of epidermal ridges? Which is most common?
Arch, loop and whorl
most common- Loop
What is the formula for finding percent recombination or map units?
Total # of recombinants/total # of offspring (x100)
What are the parental gametes of a genotype “TtRr”? What are the recombinants?
Parental- TR, tr
Recombinants- Tr, tR
How would you draw metaphase I of meiosis of a gene linkage genotype of DdEe? (Assuming no crossover occurred)
Draw four circles and make them into four chromosomes together with two gene loci on each lining up
Then label them D D d d
E E e e
Since crossing over hasn’t occurred they’re with their partners still
If you’re given the maps units and know which gametes are the parental and recombinant how can you find the percents of each then the ratio?
The percent composition is the amount of both recombinants so you divide that by two for each recombinant then subtract that from 100 and those are your parental percentages so divide that by two to get each parental percent
Then divide everything by lowest number to get ratio (lowest equal to 1)
Problem number 5 on page 136
Do sample problems on page 134-137
Okay.
