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| 1 | |
Injection of a cloned gene sequence into the syncytial gonad of a young adult hermaphrodite will usually result in insertion of the cloned gene sequence as a single copy into randomly chosen sites on chromosomes of progeny embryos. |
| | A) | True |
| | B) | False |
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| 2 | |
The pathway that determines the fate of the primary vulval precursor cell P6p is homologous to the EGF signaling pathways in mammalian cells. |
| | A) | True |
| | B) | False |
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| 3 | |
If dzy is a strict maternal-effect lethal mutation, all the embryos produced by a dzy/dzy hermaphrodite mated with a +/+ male will die. |
| | A) | True |
| | B) | False |
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| 4 | |
If m is a partial (male-rescuable) maternal-effect lethal mutation, 25% of the self-progeny embryos produced by an m/+ hermaphrodite will die. |
| | A) | True |
| | B) | False |
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| 5 | |
elegans XO individuals are somatically male. |
| | A) | True |
| | B) | False |
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| 6 | |
Using a loss-of-function (lf) allele of a mutationally identified gene, mosaic analysis can be used to determine the cells or tissues in which function of the gene is normally required (its focus of action). |
| | A) | True |
| | B) | False |
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| 7 | |
The embryonic germ layers in C. elegans, endoderm, mesoderm and ectoderm, derive from several founder cells in the early embryo. |
| | A) | True |
| | B) | False |
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| 8 | |
Most of the cells present at the end of embryogenesis divide further during postembryonic larval development. |
| | A) | True |
| | B) | False |
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| 9 | |
Cells missing from a developmental program can be replaced in: |
| | A) | dauer larva |
| | B) | hermaphrodite |
| | C) | founder |
| | D) | mosaic development |
| | E) | regulation development |
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| 10 | |
A longer-lived alternative C. elegans larva is: |
| | A) | dauer larva |
| | B) | hermaphrodite |
| | C) | founder |
| | D) | mosaic development |
| | E) | regulation development |
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| 11 | |
A form of C. elegans that is capable of self-fertilization is: |
| | A) | dauer larva |
| | B) | hermaphrodite |
| | C) | founder |
| | D) | mosaic development |
| | E) | regulation development |
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| 12 | |
Self-differentiating cells are an example of: |
| | A) | dauer larva |
| | B) | hermaphrodite |
| | C) | founder |
| | D) | mosaic development |
| | E) | regulation development |
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| 13 | |
A cell which gives rise to a specific lineage of cells is a: |
| | A) | dauer larva |
| | B) | hermaphrodite |
| | C) | founder |
| | D) | mosaic development |
| | E) | regulation development |
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| 14 | |
Which of the following is not a property of C. elegans? |
| | A) | capable of self-fertilization |
| | B) | transparent to visible light |
| | C) | nonpathogenic |
| | D) | a free-living soil nematode subsisting on bacteria |
| | E) | exists as females and hermaphrodites |
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| 15 | |
Which of the following is true about the C. elegans genome with respect to that of humans? |
| | A) | carry X and Y chromosomes |
| | B) | is about 1/30 the size |
| | C) | carry genes with introns |
| | D) | b & c |
| | E) | all of the above |
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| 16 | |
Ablation of cells in developing C. elegans : |
| | A) | eliminates cells derived from that cell |
| | B) | reduced the total cell number in viable adults |
| | C) | can cause changes in neighboring cells |
| | D) | a & b |
| | E) | all of the above |
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| 17 | |
Lineally homologous products of repeated sublineages give rise to: |
| | A) | cells of similar developmental fate that arise at different points along the length of the animal progeny cells of the same lineage clone |
| | B) | cells which differ substantially in function |
| | C) | cells which differ in founder cells |
| | D) | all of the above |
| | E) | none of the above |
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| 18 | |
Which of the following statements is not true? In C. elegans, the cells in an equivalence group: |
| | A) | are generally lineally homologous in their ancestry |
| | B) | are developmentally equivalent until receiving an external signal |
| | C) | can adopt each other's fates, with certain restrictions, in cell ablation experiments |
| | D) | can adopt different fates, with certain restrictions, in mosaic analysis experiments |
| | E) | can regenerate missing cells |
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| 19 | |
In studying mutations that affect the sensory rays in male tail development in C. elegans, you hypothesize that ray-2 represses ray-1, and ray-1 represses ray formation. You isolate loss-of function (LOF) mutations in these genes. What phenotypes do you predict? |
| | A) | ray-1 LOF shows extra rays; ray-2 LOF shows extra rays |
| | B) | ray-1 LOF shows extra rays; ray-2 LOF shows no rays |
| | C) | ray-1 LOF shows no rays; ray-2 LOF shows no rays |
| | D) | ray-1 LOF shows no rays; ray-2 LOF shows extra rays |
| | E) | ray-1/ray-2 double mutant shows no rays |
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| 20 | |
Mosaic analysis can be carried out on: |
| | A) | a recessive mutation |
| | B) | a non-maternal-effect mutation |
| | C) | a hypomorphic mutation |
| | D) | all are amenable to study |
| | E) | none are amenable to study |
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| 21 | |
elegans hermaphrodites can mate either with each other or with males. |
| | A) | True |
| | B) | False |
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| 22 | |
After mating to a male, sperm in a C. elegans hermaphrodite are not equally competent to fertilize ova. |
| | A) | True |
| | B) | False |
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| 23 | |
Recombination does not occur on the X chromosome of C. elegans. |
| | A) | True |
| | B) | False |
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| 24 | |
Polycistronic mRNA is translated in C. elegans. |
| | A) | True |
| | B) | False |
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| 25 | |
All mRNA is trans-spliced in C. elegans. |
| | A) | True |
| | B) | False |
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| 26 | |
In self fertilization, a C. elegans hermaphrodite is limited by the number of sperm made in the gonad. |
| | A) | True |
| | B) | False |
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| 27 | |
Free duplications in C. elegans can segregate fairly stably, both meiotically and mitotically, because the chromosomes are small. |
| | A) | True |
| | B) | False |
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| 28 | |
Stable chromosomal fragments in C. elegans constitute: |
| | A) | holocentric |
| | B) | heterochronic |
| | C) | trans-splicing |
| | D) | free duplication |
| | E) | RNA-mediated interference |
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| 29 | |
Polycistronic mRNA is processed in C. elegans via: |
| | A) | holocentric |
| | B) | heterochronic |
| | C) | trans-splicing |
| | D) | free duplication |
| | E) | RNA-mediated interference |
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| 30 | |
Diffuse centromeric activity typifies the C. elegans _________ chromosomes. |
| | A) | holocentric |
| | B) | heterochronic |
| | C) | trans-splicing |
| | D) | free duplication |
| | E) | RNA-mediated interference |
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| 31 | |
Gene expression in C. elegans can be disrupted by: |
| | A) | holocentric |
| | B) | heterochronic |
| | C) | trans-splicing |
| | D) | free duplication |
| | E) | RNA-mediated interference |
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| 32 | |
Mutations which alter time of expression of a gene are: |
| | A) | holocentric |
| | B) | heterochronic |
| | C) | trans-splicing |
| | D) | free duplication |
| | E) | RNA-mediated interference |
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| 33 | |
In the determination of cell fates, the phenomenon in which one cell in a set of developmentally equivalent cells takes on a specific cell fate and signals one or more neighboring cells to inhibit them from adopting the same fate is called lateral inhibition. From what is known about C. elegans, what else may be true about lateral inhibition? |
| | A) | can indirectly signal apoptosis in neighboring cells |
| | B) | mutations in pathway can be dominant |
| | C) | mutations in pathway can be recessive |
| | D) | resembles Notch/Delta signaling |
| | E) | all of the above |
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| 34 | |
If m is a recessive lethal mutation in C. elegans, the proportion of viable self progeny embryos produced by an m/+ hermaphrodite will be: |
| | A) | 0%. |
| | B) | 25%. |
| | C) | 50%. |
| | D) | 75%. |
| | E) | 100%. |
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| 35 | |
Given a C. elegans hermaphrodite of genotype unc-4/Bal, where unc-4 is a recessive mutation causing an Unc phenotype and Bal (a balancer chromosome which does not recombine) carries a recessive embryonic lethal mutation m as well as the unc-4 (+) allele, which of the following statements is correct? |
| | A) | will have an Unc phenotype. |
| | B) | will produce viable self progeny of which 1/4 are Unc. |
| | C) | will produce viable self progeny of which 2/3 are heterozygous for m |
| | D) | will produce viable self progeny of which 1/2 are Unc. |
| | E) | produce no viable self progeny |
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| 36 | |
If m is a non-maternal-effect (i.e. a so-called zygotic) mutation, which of the following statements is true? |
| | A) | 25% of the self-progeny embryos produced by an m/+ hermaphrodite will die |
| | B) | all the embryos produced by an m/m hermaphrodite mated with a +/+ male will survive. |
| | C) | only m/m males survive |
| | D) | 75% of the self-progeny embryos produced by an m/+ hermaphrodite will die |
| | E) | none of the above |
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| 37 | |
Maternal effect mutations: |
| | A) | are expressed during oogenesis |
| | B) | are always dominant |
| | C) | are not present in sperm genomes |
| | D) | are only expressed in the embryo after fertilization |
| | E) | none of the above |
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| 38 | |
In a hypothetical developmental cascade, A suppresses B, B activates C, C represses D, and D represses E. Which of the following statements is true? |
| | A) | A is off, B is on, C is on, D is off, E is on |
| | B) | A is on B is on, C is on, D is off, E is on |
| | C) | A is on, B is off, C is off, D is on, E is off |
| | D) | A is off, B is on, C is on, D is off, E is on |
| | E) | A is on, B is off, C is off, D is on, E is on |
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| 39 | |
Embryonic lethal mutations in the C. elegans par-1 gene exhibit a strict maternal effect. A par-1/+ hermaphrodite is allowed to produce self progeny. Which of the following would result? |
| | A) | 50% are par-1/par-1; all of these survive |
| | B) | 25% are par-1/par-1; all of these survive |
| | C) | 50% are par-1/par-1; all of these die |
| | D) | 25% are par-1/par-1; all of these die |
| | E) | 25% are +/+; all of these survive |
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| 40 | |
A par-1/ par-1 hermaphrodite is mated to a par-1/+ male. Which of the following would result? |
| | A) | 50% are par-1/ par-1; none of these survive |
| | B) | 50% are par-1/ par-1; all of these survive |
| | C) | 50% are par-1/+; all of these survive |
| | D) | 25% are +/+; none of these survive |
| | E) | 25% are +/+; all of these survive |
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