Question 1

A genetic test to detect predisposition to cancer would likely examine the APC gene for involvement in which type(s) of cancer?

Accepted Answer

A)   colorectal only
B)   lung and breast
C)   small intestinal and esophageal
D)   lung only
E)   lung and prostate A

Question 2

Absence of bicoid mRNA from a Drosophila egg leads to the absence of anterior larval body parts and mirror-image duplication of posterior parts. This is evidence that the product of the bicoid gene

Accepted Answer

A)   is transcribed in the early embryo.
B)   normally leads to formation of tail structures.
C)   normally leads to formation of head structures.
D)   is a protein present in all head structures.
E)   leads to programmed cell death. C

Question 3

Which of the following is true of embryonic stem cells but not of adult stem cells?

Accepted Answer

A)   They normally differentiate into only eggs and sperm.
B)   They can give rise to all cell types in the organism.
C)   They can continue to reproduce for an indefinite period.
D)   They can provide enormous amounts of information about the process of gene regulation.
E)   One aim of using them is to provide cells for repair of diseased tissue. B

Question 4

Forms of the Ras protein found in tumors usually cause which of the following?

Accepted Answer

A)   DNA replication to stop
B)   DNA replication to be hyperactive
C)   cell-to-cell adhesion to be nonfunctional
D)   cell division to cease
E)   growth factor signaling to be hyperactive

Question 5

The fact that plants can be cloned from somatic cells demonstrates that

Accepted Answer

A)   differentiated cells retain all the genes of the zygote.
B)   genes are lost during differentiation.
C)   the differentiated state is normally very unstable.
D)   differentiated cells contain masked mRNA.
E)   differentiation does not occur in plants.

Question 6

In 1997, Dolly the sheep was cloned. Which of the following processes was used?

Accepted Answer

A)   use of mitochondrial DNA from adult female cells of another ewe
B)   replication and dedifferentiation of adult stem cells from sheep bone marrow
C)   separation of an early-stage sheep blastula into separate cells, one of which was incubated in a surrogate ewe
D)   fusion of an adult cell's nucleus with an enucleated sheep egg, followed by incubation in a surrogate
E)   isolation of stem cells from a lamb embryo and production of a zygote equivalent

Question 7

Cell differentiation always involves

Accepted Answer

A)   the production of tissue-specific proteins, such as muscle actin.
B)   the movement of cells.
C)   the transcription of the myoD gene.
D)   the selective loss of certain genes from the genome.
E)   the cell's sensitivity to environmental cues, such as light or heat.

Question 8

The first cloned cat, called Carbon Copy, was a calico, but she looked significantly different from her female parent. Why?

Accepted Answer

A)   The environment, as well as genetics, affects phenotypic variation.
B)   Fur color genes in cats are influenced by differential acetylation patterns.
C)   Cloned animals have been found to have a higher frequency of transposon activation.
D)   X inactivation in the embryo is random and produces different patterns.
E)   The telomeres of the parent's chromosomes were shorter than those of an embryo.

Question 9

What is considered to be the first evidence of differentiation in the cells of an embryo?

Accepted Answer

A)   cell division occurring after fertilization
B)   the occurrence of mRNAs for the production of tissue-specific proteins
C)   determination of specific cells for certain functions
D)   changes in the size and shape of the cell
E)   changes resulting from induction

Question 10

Pax-6 is a gene that is involved in eye formation in many invertebrates, such as Drosophila. Pax-6 is found as well in vertebrates. A Pax-6 gene from a mouse can be expressed in a fly and the protein (PAX-6) leads to a compound fly eye. This information suggests which of the following?

Accepted Answer

A)   Pax-6 genes are identical in nucleotide sequence.
B)   PAX-6 proteins have identical amino acid sequences.
C)   Pax-6 is highly conserved and shows shared evolutionary ancestry.
D)   PAX-6 proteins are different for formation of different kinds of eyes.
E)   PAX-6 from a mouse can function in a fly, but a fly's Pax-6 gene cannot function in a mouse.

Question 11

The cancer-causing forms of the Ras protein are involved in which of the following processes?

Accepted Answer

A)   relaying a signal from a growth factor receptor
B)   DNA replication
C)   DNA repair
D)   cell-cell adhesion
E)   cell division

Question 12

Which of the following problems with animal cloning might result in premature death of the clones?

Accepted Answer

A)   use of pluripotent instead of totipotent stem cells
B)   use of nuclear DNA as well as mtDNA
C)   abnormal gene regulation due to variant methylation
D)   the indefinite replication of totipotent stem cells
E)   abnormal immune function due to bone marrow dysfunction

Question 13

Which of the following is characteristic of the product of the p53 gene?

Accepted Answer

A)   It is an activator for other genes.
B)   It speeds up the cell cycle.
C)   It causes cell death via apoptosis.
D)   It allows cells to pass on mutations due to DNA damage.
E)   It slows down the rate of DNA replication by interfering with the binding of DNA polymerase.

Question 14

If a Drosophila female has a homozygous mutation for a maternal effect gene,

Accepted Answer

A)   she will not develop past the early embryonic stage.
B)   all of her offspring will show the mutant phenotype, regardless of their genotype.
C)   only her male offspring will show the mutant phenotype.
D)   her offspring will show the mutant phenotype only if they are also homozygous for the mutation.
E)   only her female offspring will show the mutant phenotype.

Question 15

In colorectal cancer, several genes must be mutated in order to contribute to a cell developing into a cancer cell, supporting Knudsen's hypothesis. Which of the following kinds of genes would you expect to be mutated?

Accepted Answer

A)   genes coding for enzymes that act in the colon
B)   genes involved in control of the cell cycle
C)   genes that are especially susceptible to mutation
D)   the same genes that Knudsen identified as associated with retinoblastoma
E)   the genes of the bacteria that are abundant in the colon

Question 16

In recent times, it has been shown that adult cells can be induced to become pluripotent stem cells (iPS). In order to make this conversion, what has been done to the adult cells?

Accepted Answer

A)   A retrovirus is used to introduce four specific regulatory genes.
B)   The adult stem cells must be fused with embryonic cells.
C)   Cytoplasm from embryonic cells is injected into the adult cells.
D)   An adenovirus vector is used to transfer embryonic gene products into adult cells.
E)   The nucleus of an embryonic cell is used to replace the nucleus of an adult cell.

Question 17

The bicoid gene product is normally localized to the anterior end of the embryo. If large amounts of the product were injected into the posterior end as well, which of the following would occur?

Accepted Answer

A)   The embryo would grow to an unusually large size.
B)   The embryo would grow extra wings and legs.
C)   The embryo would probably show no anterior development and die.
D)   Anterior structures would form in both sides of the embryo.
E)   The embryo would develop normally.

Question 18

The product of the bicoid gene in Drosophila provides essential information about

Accepted Answer

A)   lethal genes.
B)   the dorsal-ventral axis.
C)   the left-right axis.
D)   segmentation.
E)   the anterior-posterior axis.

Question 19

Mutations in which of the following genes lead to transformations in the identity of entire body parts?

Accepted Answer

A)   morphogens
B)   segmentation genes
C)   egg-polarity genes
D)   homeotic genes
E)   inducers

Question 20

In animals, what is the difference between reproductive cloning and therapeutic cloning?

Accepted Answer

A)   Reproductive cloning uses totipotent cells, whereas therapeutic cloning does not.
B)   Reproductive cloning uses embryonic stem cells, whereas therapeutic cloning does not.
C)   Therapeutic cloning uses nuclei of adult cells transplanted into enucleated nonfertilized eggs.
D)   Therapeutic cloning supplies cells for repair of diseased or injured organs.

Exam 16: Development, Stem Cells, and Cancer