Unit 2: quiz questions Flashcards
In mermaids and mermen, glitter scales (g) are recessive to normal scales (G), and rainbow hair (r) is recessive to brown hair (R). These two traits are encoded by autosomal genes that are linked. A mermaid has genotype GgRr and the genes are in repulsion. Which of the following sets of genes will be found in the most common gametes produced by this mermaid? Select all that apply.
-gr
-gR**
-GR
-rr
-Gg
-Gr**
-Rr
-gg
Given the mermaids in the above question, assume that the map distance between the two genes is 22 map units. The heterozygous mermaid from the question above is crossed with a merman that has glitter scales and rainbow hair. What percent of the progeny are expected to have glitter scales and rainbow hair? Note: if your answer is 5 percent, just type 5.
11
The rate of crossing over between two linked genes (r and w) is 0.44. The following cross is carried out: Rr Ww × rr ww. What percent of the gametes of the Rr Ww parent are recombinant gametes? Note: if your answer is 5 percent, just type 5.
22
Recombination rates between three loci in bluebonnets are shown below:
Loci
%= Recombination frequency
R and W 17%
R and L 35%
W and L 18%
Which gene is in the middle?
W
The allele for long eyelashes (t+) is dominant to short eyelashes. The allele for thick bones (r+) is dominant to thin bones. These genes are linked. If a testcross is done in which one of the parents is heterozygous for these traits and the alleles are in repulsion, which of the following phenotypes would predominate among the F1?
-Short eyelashes, thin bones
-Long eyelashes, thick bones
-Short eyelashes, thick bones**
-Long eyelashes, thin bones**
In silkmoths (Bombyx mori), red eyes (re) and white-banded wings (wb) are encoded by two mutant alleles that are recessive to those that produce wild-type traits (re+ and wb+); these two genes are on the same chromosome. A moth homozygous for red eyes and white-banded wings is crossed with a moth homozygous for the wild-type traits. The F1 have normal eyes and normal wings. The F1 are crossed with moths that have red eyes and white-banded wings in a testcross. The progeny of this testcross are:
wild-type eyes, wild-type wings = 418
red eyes, wild-type wings =19
wild-type eyes, white-banded wings =16
red eyes, white-banded wings = 426
What is the percent recombination between the genes for red eyes and white-banded wings?
4%
In cucumbers, heart-shaped leaves (hl) are recessive to normal leaves (Hl) and having numerous fruit spines (ns) is recessive to having few fruit spines (Ns). The genes for leaf shape and number of spines are located on the same chromosome; findings from mapping experiments indicate that they are 32.6 m.u. apart. A cucumber plant having heart-shaped leaves and numerous spines is crossed with a plant that is homozygous for normal leaves and few spines. The F1 are crossed with plants that have heart-shaped leaves and numerous spines. What percent of the progeny will have heart-shaped leaves and few spines?
16.3%
quiz 4 #9: LOOK AT QUIZ TO SOLVE!
Priscilla Lane and Margaret Green studied the linkage relations of three genes affecting coat color in mice: mahogany (mg), agouti (a), and ragged (Rg). They carried out a series of three-point crosses, mating mice that were heterozygous at all three loci with mice that were homozygous for the recessive alleles at these loci (P. W. Lane and M. C. Green. 1960. Journal of Heredity 51:228–230). The following table lists the results of the testcrosses. Which gene is in the middle?
what is the map distance between a and Rg?
what is the coefficient of coincidence?
A
24
.031
Assume that plant weight is determined by a pair of alleles at each of two independently assorting loci (A and a, B and b) that are additive in their effects. Further assume that each allele represented by an uppercase letter contributes 4 g to weight and that each allele represented by a lowercase letter contributes 1 g to weight. If a plant with genotype AA BB is crossed with a plant with genotype aa bb, what weights are expected in the F1 progeny?
10g
Assume that the length of wheat leaves is controlled by three loci, each with two alleles: L and l, W and w, H and h. Assume each allele contributes equally to the length of the plant leaves. One homozygous strain, ll ww hh, has leaves that are 100 mm in length, and the other strain, LL WW HH, has 220 mm leaves. The two homozygous strains are crossed, and the resulting F1 are crossed to produce F2 progeny. What length will the leaves of the Ll Ww hh genotype plant be?
140mm
Which of the following types of chromosome aberrations increase the amount of genetic material in the cell? Select all that apply.
inversions
deletions
translocations
duplications**
Which of the following types of chromosome aberrations decrease the amount of genetic material in the cell? Select all that apply.
inversions
deletions**
translocations
duplications
Which of the following types of chromosome aberrations do not change the total amount of genetic material in the cell? Select all that apply.
inversions**
deletions
translocations
duplications**
A chromosome has the following segments, where * represents the centromere:
A B * C D E F G
What type of chromosome mutation is required to change this chromosome into: A B * C F E D G
Inversion
Bill and Betty have had two children with Down syndrome. Bill’s brother has Down syndrome and his sister has two children with Down syndrome. On the basis of these observations, which of the following statements is/are true? Select all that apply.
-Bill and Betty’s children each have 47 chromosomes.
-Betty has 47 chromosomes.
-Bill’s brother has 45 chromosomes.
-Bill’s sister has 45 chromosomes.**
A young couple is planning to have children. Knowing that there have been a substantial number of stillbirths, miscarriages, and fertility problems on the husband’s side of the family, they see a genetic counselor. A chromosome analysis reveals that, whereas the woman has a normal karyotype, the man possesses only 45 chromosomes and is a carrier of a Robertsonian translocation between chromosomes 21 and 14. Assuming the woman makes normal gametes, what types of zygotes could this couple produce? Select all that apply.
trisomy 21
normal
translocation carrier
monosomy 21
monosomy 14
trisomy 14
(all correct)
Species I is diploid (2n = 6) with chromosomes AABBCC; related species II is diploid (2n = 8) with chromosomes LLMMNNOO. What could be the chromosomes from an individual from one of these species that has trisomy?
-AABBCCLMNO
-ABCLLMMNNOO
Species I has 2n = 8 chromosomes and species II has 2n = 14 chromosomes. What would the expected chromosome number be in an individual organism of species I with autotetraploidy?
16
Species I has 2n = 8 chromosomes and species II has 2n = 14 chromosomes. What would the expected chromosome number be in an individual organism with allotetraploidy?
22, 19 or 25
What is the result of a trisomic embryo losing one of the triplicate chromosomes early in development, leaving the two remaining chromosomes from the same parent?
Uniparental disomy
Uracil is a:
Pyrimidine normally found in RNA
In a nucleotide, which carbon on the sugar will definitively distinguish RNA from DNA?
2’
Avery, MacLeod, and McCarty demonstrated:
that the transforming substance was DNA
Consider the Hershey and Chase experiment. Which of the following would contain 32P?
-the fluid found above the pellet
-bacterial proteins
-viral protein coats
-bacterial cells
bacterial cells
Which is true of DNA packaging in bacteria? pick one
-DNA is wrapped around histones and then supercoiled
-DNA is packaged into nucleosomes and then supercoiled
-DNA is supercoiled
-DNA is wrapped around histones and stabilized by proteins
DNA is supercoiled
A stretch of chromatin contains 8 nucleosomes. How many H2A histone proteins are found in this same stretch of chromatin?
16
For the following, circle those that apply to mtDNA (mitochondrial DNA):
-most mtDNA is single-stranded
-found in plant and animal cells
-human mtDNA does not contain introns
-mtDNA is circular
-found in plant and animal cells
-human mtDNA does not contain introns
-mtDNA is circular
What is semiconservative replication?
Replication resulting in products that consist of one strand of template DNA and one strand that has been newly synthesized
In the Meselson-Stahl experiment, which mode of replication was eliminated based on data derived after one generation of replication?
Conservative
Which of the following types of semiconservative replication requires a break in a phosphodiester bond as one of the first steps in replication?
-Linear
-Rolling Circle
-Theta
Rolling Circle
Order of bacterial DNA replication
- Initiator proteins bind to the origin of replication
- The DNA is unwound to create a replication bubble
- Primase creates an RNA primer
- DNA polymerase III begins to synthesize DNA
- DNA polymerase I removes primers and replaces them with DNA
- DNA ligase seals together any gaps in the DNA
what properties does DNA polymerase I have?
- 3’ to 5’ exonuclease activity
- 5’ to 3’ exonuclease activity
- 5’ to 3’ polymerase activity
what DNA polymerase is found in eukaryotes and initiate DNA synthesis?
DNA polymerase alpha
Which processes ensure the high accuracy of replication? (Select all that apply)
-linear replication
-mismatch repair
-nucleotide selection
-proofreading
-mismatch repair
-nucleotide selection
-proofreading
Which enzyme is responsible for the replication of chromosome ends in germ cells and certain proliferating somatic cells?
telomerase
How does telomerase work?
Extends the 3’ end so that there is more room for synthesis on the 5’ end
