MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Which of the following is involved in embryonic development?
A) cell differentiation
B) cell division
C) morphogenesis
D) A and B
E) A, B, and C
2) "Becoming specialized in structure and function" is a definition of
A) pattern formation.
B) development.
C) differentiation.
D) induction.
E) morphogenesis.
3) Without which of the following processes would all the others be impossible?
A) activation
B) cell division
C) induction
D) differentiation
E) morphogenesis
4) One striking difference between development in plants and development in animals is the importance of cell __________ in animal embryos.
A) growth
B) movement
C) division
D) differentiation
E) death
5) One striking difference between development in plants and development in animals is that in plant development
A) chemical signals play a much greater role than in animal development.
B) haploid and diploid cells are equally important.
C) growth and morphogenesis continue throughout the life of the plant.
D) cell differentiation never stops.
E) once a structure develops, it cannot reverse its path.
6) A model organism for genetic analysis must meet certain criteria. Which of these is not one of the criteria?
A) readily observable embryos
B) relatively small genomes
C) short generation times
D) the ability to produce both egg and sperm
E) knowledge of the organism
7) Of the following, which has not proven to be a useful model organism in the study of developmental genetics?
A) Caenorhabditis
B) humans
C) mice
D) Arabidopsis
E) Drosophila
8) The nematode Caenorhabditis elegans is used as a model organism for genetic studies. One of the key advantages of using Caenorhabditis elegans for study is that
A) its genome is as large as ours.
B) it has a great variety of somatic cells.
C) early stages of development proceed quickly.
D) it is hermaphroditic, making it easy to detect recessive mutations.
E) morphogenesis and growth occur throughout life.
9) The process of cellular differentiation is a direct result of
A) cell division.
B) morphogenesis.
C) differences in cellular genomes.
D) differential gene expression.
E) induction.
10) The cloning of a plant from somatic cells is consistent with the view that
A) the differentiated state is normally very unstable.
B) genes are lost during differentiation.
C) differentiated cells retain all the genes of the zygote.
D) differentiated cells contain masked mRNA.
E) cells can be easily reprogrammed to differentiate and develop into another kind of cell.
11) The ability of a transplanted nucleus to support development
A) depends on the DNA base sequence.
B) only occurs in plants.
C) depends on the size of the genome.
D) is inversely related to the age of the donor.
E) depends on the nucleus not changing.
12) A cell that remains flexible in its developmental possibilities is said to be
A) totipotent.
B) epigenic.
C) determined.
D) genomically equivalent.
E) differentiated.
13) The cloning of "Dolly" was considered a major scientific breakthrough because
A) it was the first time a surrogate mother was used successfully.
B) it was evidence that DNA methylation regulates gene expression.
C) it showed that cells can be arrested in the cell cycle.
D) it showed that differentiated adult mammal cells can dedifferentiate.
E) it proved that the pattern of gene expression is controlled at transcription.
14) All of the following statements are true about stem cells except:
A) Stem cell DNA lacks introns.
B) Stem cells are found in the adult human brain.
C) Stem cells can differentiate into specialized cells.
D) Stem cells are found in bone marrow.
E) Stem cells can continually reproduce themselves.
15) The first evidence of differentiation is
A) determination.
B) changes resulting from induction.
C) changes in the size and shape of the cell.
D) cell division.
E) the occurrence of mRNAs for the production of tissue-specific proteins.
16) In most cases, differentiation is controlled at the level of
A) replication of the DNA.
B) nucleosome formation.
C) translation.
D) post-translational activation of the proteins.
E) transcription.
17) Which of the following serve as sources of developmental information?
A) signal molecules produced by neighboring cells
B) cytoplasmic determinants such as mRNAs and proteins produced before fertilization
C) tissue-specific proteins
D) A and B
E) A, B, and C
18) Which features of the unfertilized egg serve as sources of developmental information?
A) proteins
B) gradients of small molecules such as calcium ions
C) RNA molecules
D) A and B
E) A, B, and C
19) "The development of spatial organization in which the tissues and organs are all in their characteristic places" is a definition of
A) induction.
B) pattern formation.
C) morphogenesis.
D) differentiation.
E) development.
20) One difference between development in plants and development in animals involves pattern formation because
A) pattern formation is limited to specific locations in plants, but occurs in all parts of animals.
B) pattern formation is continuous in animals and limited to early development in plants.
C) pattern formation occurs in all parts of the plant, but is limited to specific locations in animals.
D) pattern formation is continuous in plants and limited to early development in animals.
E) A and C are correct.
21) Your brother, Todd, has just purchased a new plastic model of an airplane. He removes it from the box and places all the parts on the table in approximately the positions they will finally be located when the model is put together. Todd's actions are analogous to which process in development?
A) morphogenesis
B) development
C) differentiation
D) pattern formation
E) induction
22) A cell's location relative to the body axes in an animal embryo is determined by molecular clues that control pattern formation. Which of the following contribute to positional information in Drosophila?
A) egg polarity genes
B) tissue-specific proteins
C) bicoid mRNA
D) A and C only
E) A, B, and C
23) Of the approximately 12,000 genes in Drosophila, what proportion are essential for embryonic development?
A) 2% (about 240 genes)
B) 10% (about 1,200 genes)
C) 50% (about 6,000 genes)
D) 75% (about 9,000 genes)
E) 1% (about 120 genes)
24) The product of the bicoid gene in Drosophila provides essential information about
A) the left-right axis.
B) the head-tail axis.
C) segmentation.
D) lethal genes.
E) the dorsal-ventral axis.
25) Suppose a mutation occurred in Drosophila in the region of DNA that codes for the protein called bicoid. What is most likely to happen during development?
A) The transcription of developmental genes will stop.
B) The fertilized egg will be bipolar.
C) The polarity of the fertilized egg will be disrupted.
D) Two sets of limbs will form in a mirror-image arrangement.
E) The embryos will express their father's genotype.
SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question.
For the following questions, use the following responses:
A. bicoid gene
B. gap genes
C. pair-rule genes
D. segment-polarity genes
E. homeotic genes
26) Which map out the basic subdivisions along the anterior-posterior axis of the Drosophila embryo?
27) Which define the modular pattern of segments?
28) Which sets the anterior-posterior polarity of the segment?
29) Which establishes the overall anterior-posterior axis of the embryo?
30) The failure of which of these would result in an embryo with only half the normal number of segments?
31) The failure of which of these would result in an embryo lacking groups of body segments?
32) The failure of which of these would result in an embryo with the normal number of segments, but having parts of some segments replaced by mirror-image repeats of other segments?
33) Which of these do all the others rely upon?
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
34) Generals map out an overall plan of a war. Colonels determine the plans for specific battles. Majors decide which units will perform each function, and captains determine which soldiers will have which jobs. Given this analogy, gap genes function like
A) majors. B) colonels. C) captains. D) soldiers. E) generals.
35) The product of the bicoid gene in Drosophila could be considered a
A) tissue-specific protein.
B) cytoplasmic determinant.
C) morphogen.
D) B and C.
E) A, B, and C.
36) Given the function of the bicoid gene product, if the gene were cloned and large amounts of the product were injected into eggs, which of the following would be true?
A) The embryos would grow much larger.
B) The embryos would develop normally.
C) The embryos would grow extra wings and legs.
D) Anterior structures would form in the area of injection.
E) The embryos would die and probably show no anterior development.
37) What do gap genes, pair-rule genes, segment-polarity genes, and homeotic genes all have in common?
A) They have no counterparts in animals other than Drosophila.
B) Their products act as transcription factors.
C) They act independently of other positional information.
D) Their products are all synthesized prior to fertilization.
E) They apparently can be activated and inactivated at any time of the fly's life.
38) Which of the following is least related to the others?
A) morphogenesis
B) induction
C) bacterial transformation
D) cell division
E) differentiation
39) Which of the following is least related to the others?
A) pair-rule genes
B) gap genes
C) cyclin genes
D) segment-polarity genes
E) segmentation genes
40) Which of the following is least related to the others?
A) morphogens
B) induction
C) cytoplasmic determinants
D) homeotic genes
E) totipotent
41) All of the following are true concerning homeotic genes except:
A) A DNA sequence of 180 nucleotides is common to all of the genes.
B) They are translated into peptide sequences called homeodomains.
C) A mutation may cause misplacement of body segments.
D) They are the primary inducer of frog morphogenesis.
E) The peptide gene product is a regulatory protein that controls transcription.
42) Which of the following statements concerning homeotic genes is correct?
A) There is a sequence of 180 nucleotides common to all the genes.
B) They are translated into homeodomains that function as transcription factors.
C) They are egg-polarity genes that code for morphogens.
D) Only A and B are correct.
E) A, B, and C are correct.
43) The term homeobox refers to
A) a specific nucleotide sequence of some genes that regulate development.
B) a group of genes that determine polarity during development.
C) glycoproteins that assist cells during morphogenetic movements.
D) zones of polarizing activity commonly present during limb formation.
E) peptide sequences of 60 amino acids that turn other genes on or off.
44) Why is a certain 180-nucleotide sequence in many developmental genes called a homeobox?
A) because when it was first cloned, it could only be inserted into a bacterial plasmid called "box"
B) because virtually the same sequence is found in every homeotic gene
C) because it contains no introns
D) because it was first cloned by Dr. H. O. Meobox
E) because it reads the same forwards as backwards
45) A small, impermeable membrane is placed between the anchor cell and the other vulva precursor cells in a larva of C. elegans. What would you expect the result to be?
A) The vulva would continue to develop normally.
B) The inner part of the vulva would develop, but the outer part would not.
C) The outer part of the vulva would develop, but the inner part would not.
D) The vulva would not develop at all.
E) Only the posterior part of the vulva would develop.
46) Which of the following statements is false?
A) Induction involves cells communicating with each other.
B) Induction can play an essential role in the formation of complex organs.
C) Induction signals are almost always small carbohydrates.
D) Induction may involve stimulating cells to die as well as to divide and grow.
E) Induction usually involves transcriptional regulation.
47) Which of the following is least related to the others?
A) pattern formation
B) apoptosis
C) maternal effect genes
D) positional information
E) egg-polarity genes
48) Which of the following might involve apoptosis?
A) Cells from the top of the mouth combine with cells from the base of the brain to form the pituitary.
B) As the bones of the spinal column form, they develop from blocks of undifferentiated tissue called somites.
C) If part of the developing spinal chord in a frog embryo is transplanted to just under the skin of the back, it will stimulate development of an eye in that location.
D) Interactions between muscle cells and bone cells that guide the growth of the muscle to a specific location so it can attach to the bone.
E) Gonads begin as an undifferentiated organ that can form either an ovary or a testis. At a certain time, hormonal signals trigger the growth of some cells and the death of others to form an ovary or testis.
49) In vertebrates, programmed cell death is essential for all of the following reasons except
A) normal triggering of the single-transduction pathways.
B) normal removal of damaged cells.
C) normal operation of the immune system.
D) normal morphogenesis of human feet.
E) normal development of the nervous system.
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