BGYB11 Midterm 1
1. Mendel’s law of independent assortment states that
segregation of an allelic pair for one trait had no effect on the segregation of alleles for another trait.
2. How many chromosomes would a sexually reproducing organism with 6 chromosomes in generation 1 have in
generation 4 if the normal reductional division takes place in meiosis?
3. If pollen from a plant that is hetero for a mutant allele is used to fertilize another plant that is null for the allele,
what is the expected ratio of progeny?
half offspring are heterozygotes
4. If primary non-disjunction occurs at spermatogenesis:
half gametes have an extra chromosome
5. During the first meiotic division, HOMOLOGS segregate one another, second meiotic division, the SISTER
CHROMATIDS segregate from one another.
6. Consider a single autosome (e.g. chromosome 4) that you have. Which statement is always true?
a. I received more of chromosome 4 DNA from my maternal grandparents than my paternal grandparents
b. I received 25% of my chromosome 4 DNA from each of my grandparents
c. I received either 0% or 50% of my chromosome 4 DNA from my paternal grandfather
d. I received either 50% or 100% of my chromosome 4 DNA from my maternal grandfather
e. None of the above
7. Suppose that you had two solutionns of DNA, one single stranded (ssDNA) and the other double stranded
(dsDNA). You take some of each and determine that UV light absorption by the single stranded sample is 50%
greater than that of the double stranded sample. What does this tell you about the relative concentrations of DNA
in the original samples?
a. the ssDNA is 0.5 times more concentrated than the dsDNA
b. the ssDNA is 2 times as concentrated as the dsDNA
c. the dsDNA is 0.5 times more concentrated than the ssDNA
d. the dsDNA is 2 times as concentrated as the ssDNA
e. the two samples have the same concentration
8. Consider two organisms with genomes of equal size. The GC content of the first is 40% while that of the second
is 33%. Which of the following statements is true?
a. the melting temperature of genome 1 is lower than that of genome 2
b. the melting temperature of genome 2 is lower than that of genome 1
c. the complexity of genome 1 is greater than that of genome 2
d. both a and c
e. both b and c
9. Based on Chargaff’s observations on base composition of DNA, which of the following mathematical statements
are true of every double stranded DNA sample?