Identify the molecule or structure described: a protein important in sperm motility.

Choose one answer.

	a. Bindin
	b. Vitelline envelope
	c. Cortical granules
	d. Dynein

Question 2

Identify the molecule or structure described: involved in the slow reaction against polyspermy in sea urchins.

Choose one answer.

	a. Bindin
	b. Vitelline envelope
	c. Cortical granules
	d. Dynein

Question 3

If you inactivated the glycoprotein ZP3 on a mouse oocyte, which of the following would be directly affected?

Choose one answer.

	a. The activation of egg metabolism
	b. The primary binding of sperm to the zona pellucida
	c. The secondary binding of sperm to the zona pellucida
	d. The absorption of nutrients into the egg's cytoplasm

Question 4

If you were to reduce the amount of sodium available in the seawater around sea-urchin eggs, which of the following would be directly affected?

Choose one answer.

	a. The activation of egg metabolism
	b. The slow reaction to prevent polyspermy
	c. The fast reaction to prevent polyspermy
	d. The binding of sperm and egg

Question 5

The concept that sperm were "seeds" of life that were provided by the female with nutrients, but no other material, was an idea supported by whom?

Choose one answer.

	a. Hertwig and Fol
	b. Leeuwenhoek
	c. Aristotle
	d. Both B and C

Question 6

Which of the following is false in regards to chemotaxis?

Choose one answer.

	a. It is most important in species with external fertilization.
	b. It involves chemicals that have powerful effects at very low concentrations.
	c. It involves chemicals that are present in sperm at higher and higher doses as they mature.
	d. It involves the creation of a concentration gradient.

Question 7

Which of the following observations would support the preformationist view of how embryos develop?

Choose one answer.

	a. The blood vessels of chicks form before the heart.
	b. The intestinal tube forms by the folding of tissue that was once flat.
	c. Each generation organisms are created anew.
	d. Embryonic organs develop from different tissues than their adult counterparts.

Question 8

Which of these discoveries was not made until the late 1800s?

Choose one answer.

	a. Fertilization occurs as a fusion of a sperm and an egg.
	b. Cleavage occurs through either the entire egg dividing into smaller cells or a small portion of the egg dividing and forming the embryo.
	c. All animals, even mammals, derive from eggs.
	d. The intestinal tube forms by the folding of tissue that was once flat.

Question 9

Which of these is involved in the initiation of egg metabolism?

Choose one answer.

	a. Calcium
	b. Sodium
	c. Potassium
	d. Hydrogen

Question 10

You want to increase fertility in your laboratory mice, and you think that a way to do it would be to block any reactions that would modify ZP2 and ZP3. Is this a good idea? Why or why not?

Choose one answer.

	a. Yes, because you will ensure that these proteins are able to function properly in binding sperm to the egg.
	b. No, because these proteins are only marginally involved in chemoattraction and will not affect fertilization success.
	c. No, because while you might increase fertilization success, you will block the egg's ability to prevent polyspermy.
	d. Yes, because you will ensure that the cumulus does not thicken too early in fertilization.

Question 11

Which of the following is in fact a contradiction of von Baer's principles of embryological development?

Choose one answer.

	a. Vertebrate embryos in their early stages of development are difficult to tell apart.
	b. As the embryos of "higher" (more recently evolved) vertebrate species develop, they resemble the adult stages of various ancestral forms.
	c. Early vertebrate embryos all have the same type of skin, only later growing scales, hair, or feathers.
	d. Vertebrate embryos resemble one another early in development but later do not resemble other species, only their own.

Question 12

Different spliceosomes recognize different sequences, resulting in whole families of "splicing isoform" proteins. This is an example of gene regulation at what level?

Choose one answer.

	a. RNA processing
	b. Post-translational modification
	c. Transcription
	d. Translation

Question 13

In the oocyte, some mRNAs are bound to by inhibitory proteins or are ignored by cellular processing, because they have too short a poly(A) tail. This is an example of gene regulation at what level?

Choose one answer.

	a. RNA processing
	b. Post-translational modification
	c. Transcription
	d. Translation

Question 14

Insulin does not function until the inhibitory sections of its initial protein form are cleaved. This is an example of gene regulation at what level?

Choose one answer.

	a. RNA processing
	b. Post-translational modification
	c. Transcription
	d. Translation

Question 15

Reporter genes, such as green florescent protein (GFP), which are used to visualize gene expression in cells, are inserted intro transgenes in association with what?

Choose one answer.

	a. Promoters
	b. Enhancers
	c. Transcription factors
	d. Introns

Question 16

Which of these is the correct, if abridged, description of how crystalline-lens gene expression (related to eye development) is regulated?

Choose one answer.

	a. Pax6 works in combination with Sox2 to allow the transcription of the gene in the appropriate tissues.
	b. The lens gene is transcribed but is prevented from transport into the cytoplasm; it remains in the nucleus until it is degraded.
	c. The gene is stabilized in cells fated to become the lens by the addition of a longer poly(A) tail.
	d. The enzyme deltaEF1 phosphorylates the otherwise-inactive crystalline-lens protein, after it has been translated.

Question 17

You want to be able to see where (in what areas and tissues) in a chick embryo a particular gene is expressed. Choose the technique that is most appropriate for the study you want to do or the question you want to answer. (Please note that any technique that does more than you need probably costs more too, so it would not be the best choice.)

Choose one answer.

	a. Northern blot
	b. Making a quail-chick chimera
	c. In situ hybridization
	d. PCR

Question 18

You want to compare the expression of a gene in an early-embryonic kidney vs. a late-embryonic kidney. You are not concerned with visualizing the tissues; you just want to know when the gene is expressed. Choose the technique that is most appropriate for the study you want to do or the question you want to answer. (Please note that any technique that does more than you need probably costs more too, so it would not be the best choice.)

Choose one answer.

	a. Northern blot
	b. Making a quail-chick chimera
	c. In situ hybridization
	d. PCR

Question 19

You want to determine the effect of a gene from a different species on mouse development, and you want to be able to observe this effect where only certain cells express the gene in animals of mixed lineage and in animals that are homozygous for the new allele. Choose the technique that is most appropriate for the study you want to do or the question you want to answer. (Please note that any technique that does more than you need probably costs more too, so it would not be the best choice.)

Choose one answer.

	a. Genetic knockout
	b. Insertion via retroviral vector
	c. Making a transgenic mouse
	d. Antisense RNA

Question 20

You want to determine the fate of individual cells once an embryo develops. Choose the technique that is most appropriate for the study you want to do or the question you want to answer. (Please note that any technique that does more than you need probably costs more too, so it would not be the best choice.)

Choose one answer.

	a. Northern blot
	b. Making a quail-chick chimera
	c. In situ hybridization
	d. PCR

Question 21

You want to know whether a particular gene is expressed in very early mouse development, but you do not have enough mRNA to analyze. Choose the technique that is most appropriate for the study you want to do or the question you want to answer. (Please note that any technique that does more than you need probably costs more too, so it would not be the best choice.)

Choose one answer.

	a. Genetic knockout
	b. Insertion via retroviral vector
	c. In situ hybridization
	d. PCR

Question 22

You suspect that your gene of interest is involved in ear development in mice. You decide to study the ears of mice in which this gene has been partially inactivated. Choose the technique that is most appropriate for your study or the question you want to answer. (Please note that any technique that does more than you need probably costs more too, so this would not be the best choice.)

Choose one answer.

	a. Genetic knockout
	b. Insertion via retroviral vector
	c. In situ hybridization
	d. PCR

Question 23

The development of identical twins, when cleavage-stage cells of one embryo are divided into two groups and each grow into an individual, occurs through which type of specification?

Choose one answer.

	a. Autonomous
	b. Syncytial
	c. Semelparous
	d. Conditional

Question 24

The fates of later cells and tissues are influenced by concentration gradients in the cytoplasm of a single cell with many nuclei. This is an example of what type of specification?

Choose one answer.

	a. Autonomous
	b. Syncytial
	c. Semelparous
	d. Conditional

Question 25

The fertilized eggs of which of these groups go through meroblastic cleavage?

Choose one answer.

	a. Sea urchins
	b. Amphibians
	c. Birds
	d. Mammals

Question 26

What is the function of the blastocoel (as described in the section on amphibian cleavage)?

Choose one answer.

	a. It serves as a buffer, preventing cells below it from affecting cells above it.
	b. It has no function and occurs as a byproduct of the cleavage process.
	c. It induces the formation of the blastopore.
	d. It forms the gut in later development.

Question 27

Which of these cells, tissues, or factors, if removed or inactivated, would have the greatest effect on the induction of tissues in sea-urchin eggs (i.e., which is at the top of the induction cascade)?

Choose one answer.

	a. Veg1
	b. β-catenin
	c. Veg2
	d. Micromeres

Question 28

Which of these is false for most organisms?

Choose one answer.

	a. During early cleavage, stored maternal proteins and mRNAs control development, and virtually no activity is undergone by the zygote's genome.
	b. Division occurs without any increase in the volume of the cell.
	c. The initiation of cleavage is inhibited by MPF.
	d. All of the above

Question 29

Which of these is false in regards to yolk in fertilized eggs?

Choose one answer.

	a. It provides nutrients for developing embryos.
	b. It helps determine the pattern and distribution of cleavage.
	c. It inhibits cleavage.
	d. None of the above

Question 30

Which of these processes, unique to mammalian cleavage, is the first step in the formation of the chorion (embryonic portion of the placenta)?

Choose one answer.

	a. Compaction
	b. Rotational cleavage
	c. Early activation of the zygotic genome
	d. Asynchronous cell division

Question 31

Which pole of the egg has the most yolk?

Choose one answer.

	a. The animal pole
	b. The vegetal pole
	c. Neither has yolk
	d. Both have the same amount of yolk

Question 32

You are an organism whose eggs have very little yolk. Which of the following is most likely to be true?

Choose one answer.

	a. Your eggs undergo meroblastic cleavage.
	b. Your eggs divide at a slower rate than those with a great deal of yolk.
	c. Your young go through a larval stage in which they eat a great deal.
	d. Your eggs undergo discoidal cleavage.

Question 33

A blastomere removed from a very early embryo develops into the same cells it would have done within the embryo, and the embryo from which it is removed lacks those same cells. This is an example of what type of specification?

Choose one answer.

	a. Autonomous
	b. Syncytial
	c. Semelparous
	d. Conditional

Question 34

Which of these aspects of gastrulation supports our understanding of which species arose from which common ancestors?

Choose one answer.

	a. Frog and avian gastrulation events are nearly identical.
	b. Mammalian gastrulation events are very similar to avian and reptilian events in spite of their eggs no longer having large amounts of yolk.
	c. Gastrulation events in amphibians are initiated by the same cell signals that are used in sea-urchin gastrulation.
	d. Gastrulation in birds goes through stages that reiterate the development of all earlier vertebrate groups.

Question 35

Which of these movements involves the spreading of the mesoderm over the entire internal surface of cells in amphibians?

Choose one answer.

	a. Involution
	b. Ingression
	c. Delamination
	d. Epiboly

Question 36

Which of these movements is involved in the creation of parallel cellular sheets during avian hypoblast formation?

Choose one answer.

	a. Involution
	b. Ingression
	c. Delamination
	d. Epiboly

Question 37

Which of these movements results in the covering of the embryo with a layer of ectoderm?

Choose one answer.

	a. Involution
	b. Ingression
	c. Delamination
	d. Epiboly

Question 38

Which of these movements results in the covering of the embryo with a layer of ectoderm?

Choose one answer.

	a. Invagination
	b. Involution
	c. Ingression
	d. Epiboly

Question 39

Which of these structures develops into the primitive gut?

Choose one answer.

	a. Blastocoel
	b. Cytotrophoblast
	c. Archenteron
	d. Epiblast

Question 40

Which of these structures in birds is analogous to the frog blastopore and why?

Choose one answer.

	a. The primitive groove, because it provides the opening through which cells migrate into the blastocoel.
	b. The scatter factor, because it defines the dorsal portion of the embryo.
	c. The germinal crescent, because it initiates gastrulation.
	d. There is no avian equivalent to the frog blastopore because of their different patterns of cleavage and gastrulation.

Question 41

Which organisms, because of the sequence of events establishing the head mesoderm and notochord, have what Professor Scott Gilbert calls a "head start" (i.e., anterior structures develop earlier than posterior structures)?

Choose one answer.

	a. Sea urchins
	b. Frogs
	c. Birds and mammals
	d. Mammals

Question 42

Why is the point of sperm entry important in amphibian gastrulation?

Choose one answer.

	a. It is the point at which gastrulation is initiated.
	b. The cells opposite it will become the blastopore.
	c. It induces the necessary movement of the egg cytoplasm.
	d. It marks the future dorsal portion of the embryo.

Question 43

You observe a number of frog embryos that lack normal fate maps. You suspect that these early embryos were exposed to chemicals that depleted their levels of which of the following?

Choose one answer.

	a. VegT
	b. Sonic hedgehog
	c. Distal
	d. Cortical cytoplasm

Question 44

Identify the germ layer from which the majority of the following structure arose: the lining of the gut.

Choose one answer.

	a. Ectoderm
	b. Mesoderm
	c. Endoderm
	d. Neural crest

Question 45

Identify the gene/protein involved in the development of anterior structures in Drosophila.

Choose one answer.

	a. Nanos
	b. Caudal
	c. Gurken
	d. Bicoid

Question 46

Identify the result of the following experimental manipulation in amphibians: separation of the first two blastomeres, such that each receives one-half of the gray crescent.

Choose one answer.

	a. Two normal frog embryos
	b. One normal frog embryo and one mass of tissue
	c. One conjoined-twin frog embryo
	d. A mutant, non-viable embryo

Question 47

Identify the result of the following experimental manipulation in amphibians: transplantation of dorsal-lip tissue to the area that usually becomes the ventral epidermis.

Choose one answer.

	a. Two normal frog embryos
	b. One normal frog embryo and one mass of tissue
	c. One conjoined-twin frog embryo
	d. A mutant, non-viable embryo

Question 48

Identify the result of the following experimental manipulation in amphibians: irradiation of the oocyte during fertilization.

Choose one answer.

	a. Two normal frog embryos
	b. One normal frog embryo and one mass of tissue
	c. One conjoined-twin frog embryo
	d. A mutant, non-viable embryo

Question 49

If you altered the pH gradient set up in a chick embryo, which process would you directly affect?

Choose one answer.

	a. Left-right axis formation
	b. Dorsal-ventral axis formation
	c. Anterior-posterior axis formation
	d. Specification of the ectoderm

Question 50

If you wanted to make a frog embryo produce only epidermis and no neural structures from its ectoderm, what would you do?

Choose one answer.

	a. Block the factors that inhibit ectoderm from developing into its "default fate"
	b. Overexpress the inhibitory factors within the organizer (e.g. follistatin, chordin)
	c. Block the factors that inhibit BMP4 expression
	d. Both A and B

Question 51

Which is false in regards to the amphibian Nieuwkoop center?

Choose one answer.

	a. It is specified but not determined.
	b. It is composed of the dorsal-most vegetal cells.
	c. It induces the organizer.
	d. It occurs opposite the point of sperm entry.

Question 52

Which is NOT something that frogs and Drosophila have in common in terms of axis patterning and formation?

Choose one answer.

	a. Both rely upon gradients of proteins and mRNAs to induce appropriate structures in appropriate regions along the anterior-posterior axis.
	b. Both have homeotic genes whose expression patterns control the development of regions of the body.
	c. Both form their anterior-posterior axis after dorsal-ventral axis formation has been induced.
	d. All of the above

Question 53

Which of these does NOT affect the axis formation of chick embryos?

Choose one answer.

	a. pH
	b. Nanos
	c. Gravity
	d. β-catenin

Question 54

You want to "rescue" a UV-treated amphibian embryo (that is, allow it to develop normally). Which of the following would allow you to do so?

Choose one answer.

	a. Transplanting the dorsal lip of the blastopore from an untreated embryo to the same site on a treated embryo
	b. Transplanting the dorsal-most blastomeres from an untreated embryo to the same site on a treated embryo
	c. Rotating the embryo 180 degrees before the 32-cell stage
	d. Either A or B would allow you to rescue the embryo.

Question 55

Which of these is true of left-right axis formation in the frog and chick?

Choose one answer.

	a. Both are influenced by the asymmetric expression of the genes iv and inv.
	b. Both are influenced by the presence of a nodal gene on the left side of the embryo which activates pitx2.
	c. In both, right-side structures are initiated by the activation of snail, and left-side structures are initiated by the activation of pitx2.
	d. In both, left-right axis patterning is initiated by the presence of Noggin and Cerberus proteins.

Question 56

A developmental biologist studying the effect of pollutants on frog abnormalities observes an interesting occurrence: if tadpoles whose tails are severed are exposed to a particular pollutant, their tail area, instead of regenerating, will grow legs! The biologist hypothesizes that the pollutant mimics the behavior of what tissue or factor?

Choose one answer.

	a. The AER
	b. BMP
	c. Retinoic acid (RA)
	d. Noggin

Question 57

False hellebore is a toxic plant, whose properties inhibit Sonic hedgehog expression. Sheep that eat hellebore often give birth to young with a single eye (a mutation called "cyclopia"). Given what you know about Sonic hedgehog, what disruption to embryonic development could cause this?

Choose one answer.

	a. Pax6 expression is not downregulated in the center of the brain.
	b. The migration of ectoderm to the developing face is not initiated.
	c. Hox gene constellations in the head are not expressed.
	d. The gradient of TGF-β proteins in the face is not established.

Question 58

Identify the result of the following disruption on vertebrate-limb development: blocking BMP throughout the interdigital zone.

Choose one answer.

	a. Upside-down digits
	b. Development of hind-limb structures in forelimb area
	c. Webbing and/or no separation of digits
	d. Absence of distal limb structures

Question 59

Identify the result of the following disruption on vertebrate-limb development: rotating limb ectoderm 180 degrees.

Choose one answer.

	a. Upside-down digits
	b. Development of hind-limb structures in forelimb area
	c. Webbing and/or no separation of digits
	d. Absence of distal limb structures

Question 60

Identify the result of the following disruption on vertebrate-limb development: removal of the AER.

Choose one answer.

	a. Upside-down digits
	b. Development of hind-limb structures in forelimb area
	c. Webbing and/or no separation of digits
	d. Absence of distal limb structures

Question 61

Identify the result of the following disruption on vertebrate-limb development: expression of Tbx4 throughout the trunk.

Choose one answer.

	a. Upside-down digits
	b. Development of hind-limb structures in forelimb area
	c. Webbing and/or no separation of digits
	d. Absence of distal limb structures

Question 62

Thoracic neural crest cells, which become adrenergic neurons, can become cholinergic neurons if they are transplanted to the neck. This is an example of which of the following?

Choose one answer.

	a. Autonomous development
	b. Pluripotency
	c. Differentiation
	d. Syncytial development

Question 63

What is the origin of most of the structures of the face?

Choose one answer.

	a. Paraxial mesoderm
	b. Intermediate mesoderm
	c. Neural crest
	d. Lateral-plate mesoderm

Question 64

What is the origin of the vertebrae, ribs, and most skeletal muscle?

Choose one answer.

	a. Paraxial mesoderm
	b. Intermediate mesoderm
	c. Neural crest
	d. Lateral-plate mesoderm

Question 65

Which of the following develops into the functioning adult kidney in humans?

Choose one answer.

	a. Mesonephros
	b. Metanephros
	c. Pronephros
	d. Germinativum

Question 66

Which of the following is the area between the splanchnopleure and the somatopleure?

Choose one answer.

	a. Chorion
	b. Archenteron
	c. Blastocoel
	d. Coelom

Question 67

A new horror movie, inspired by insect metamorphosis, has the following plot. A few humans are abducted by aliens; they are then returned to earth with no memory of their time in space, but medical tests reveal strange clusters of foreign cells throughout their body. The cell clusters do not seem to do anything, though. After a period of time, a pulse of light is sent to earth from outer space. The first pulse causes the abductees to wrap themselves in blankets and secrete a covering that seals the blankets over them. While they are within their blankets, their own bodies disintegrate and the clusters of cells within them form new structures. Another pulse of light is sent from space, and the former abductees break out of their wrappings; they look nothing like the humans they were, and-of course, this being a horror movie-they want to kill everybody. In this movie, the clusters of cells most closely resemble what in insect metamorphosis?

Choose one answer.

	a. Juvenile hormone (JH)
	b. 20-hydroxyecdysone
	c. Imaginal discs
	d. Pupae

Question 68

A new horror movie, inspired by insect metamorphosis, has the following plot. A few humans are abducted by aliens; they are then returned to earth with no memory of their time in space, but medical tests reveal strange clusters of foreign cells throughout their body. The cell clusters do not seem to do anything, though. After a period of time, a pulse of light is sent to earth from outer space. The first pulse causes the abductees to wrap themselves in blankets and secrete a covering that seals the blankets over them. While they are within their blankets, their own bodies disintegrate and the clusters of cells within them form new structures. Another pulse of light is sent from space, and the former abductees break out of their wrappings; they look nothing like the humans they were, and-of course, this being a horror movie-they want to kill everybody. In this movie, the pulses of light that trigger these changes most closely resemble what in insect metamorphosis?

Choose one answer.

	a. Juvenile hormone (JH)
	b. 20-hydroxyecdysone
	c. Imaginal discs
	d. Pupae

Question 69

A new horror movie, inspired by insect metamorphosis, has the following plot. A few humans are abducted by aliens; they are then returned to earth with no memory of their time in space, but medical tests reveal strange clusters of foreign cells throughout their body. The cell clusters do not seem to do anything, though. After a period of time, a pulse of light is sent to earth from outer space. The first pulse causes the abductees to wrap themselves in blankets and secrete a covering that seals the blankets over them. While they are within their blankets, their own bodies disintegrate and the clusters of cells within them form new structures. Another pulse of light is sent from space, and the former abductees break out of their wrappings; they look nothing like the humans they were, and-of course, this being a horror movie-they want to kill everybody. In this movie, the blanket wrappings most closely resemble what in insect metamorphosis?

Choose one answer.

	a. Juvenile hormone (JH)
	b. 20-hydroxyecdysone
	c. Imaginal discs
	d. Pupae

Question 70

If you blocked the transcription of all genes on the Y chromosome of a fruit-fly (Drosophila), what would happen?

Choose one answer.

	a. The fly would develop as a fertile female.
	b. The fly would develop as a fertile male.
	c. The fly would develop as a sterile male.
	d. The fly would develop as a sterile female.

Question 71

If you blocked the transcription of all genes on the Y chromosome of a mammal, what would happen?

Choose one answer.

	a. The mammal would develop as a fertile female.
	b. The mammal would develop as a fertile male.
	c. The mammal would develop as a sterile male.
	d. The mammal would develop as a sterile female.

Question 72

In which of the following groups of organisms is the male's X chromosome activity doubled to match the two X chromosomes of females?

Choose one answer.

	a. Drosophila fruit-flies
	b. Mammals
	c. Most turtles and all crocodilians
	d. Crepidula fornicata snails

Question 73

Many pollutants have been found to mimic hormones or to initiate or repress various physiological functions. Which of the following would most adversely affect organisms with environmental sex determination (ESD)?

Choose one answer.

	a. A pollutant that blocks the transcription of Sry
	b. A pollutant that blocks the action of aromatase
	c. A pollutant that mimics Sox9
	d. A pollutant that mimics Sex-lethal (Sxl)

Question 74

The dedifferentiation and respecification of structures and cells is involved in what type of regeneration and what sort of organism?

Choose one answer.

	a. Epimorphosis, hydra
	b. Epimorphosis, newts
	c. Compensatory regeneration, liver
	d. Morphallaxis, newts

Question 75

The repatterning of tissue based on morphogenetic gradients is involved in what type of regeneration and what sort of organism?

Choose one answer.

	a. Epimorphosis, hydra
	b. Epimorphosis, newts
	c. Compensatory regeneration, liver
	d. Morphallaxis, hydra

Question 76

Which of these is false in regards to frog metamorphosis?

Choose one answer.

	a. It involves a reorganization of virtually every organ.
	b. It relies on a threshold response with different tissues responding to different concentrations of hormones.
	c. It can be inhibited by the removal of the pancreas.
	d. The hormones involved in it primarily regulate gene transcription.

Question 77

You want to create a much bigger caterpillar than a species normally makes. This caterpillar normally has only five instars before pupating; you decide to make it go through eight instars, thus causing it to grow bigger with each molt. What factor would you expose the caterpillar to in order to make it continue to molt into instars?

Choose one answer.

	a. Juvenile hormone (JH)
	b. 20-hydroxyecdysone
	c. Thyroxine
	d. PTTH

Question 78

Conservationists wanted to help increase the populations of endangered sea turtles. They gathered a number of sea-turtle eggs from a beach and raised them in the lab in a protected environment and at a constant temperature (32º C). The young turtles all hatched and were all healthy, but they later they would not produce any young. Why?

Choose one answer.

	a. Turtle eggs must be raised at a fluctuating temperature in order to develop functioning gonads; these turtles were all sterile.
	b. The high temperature inactivated the transcription factors involved in initiating gonadal development from the turtles' X and Y chromosomes.
	c. The high temperatures stimulated the hormonal induction of female sex development; the turtles were fertile but all female.
	d. The turtles' gonads developed normally, but the constant temperature prevented the hormonal induction of secondary sex characteristics, and they could not display mating behaviors.

Question 79

Domestication often results in animals that resemble the young of their wild predecessors. This is an example of what type of developmental process?

Choose one answer.

	a. Duplication and divergence
	b. Co-option
	c. Dissociation (allometry)
	d. Dissociation (heterochrony)

Question 80

It is thought that the dorsal shell of turtles is made by using a combination of limb-development pathways and skull-development pathways. This is an example of what type of developmental process?

Choose one answer.

	a. Duplication and divergence
	b. Co-option
	c. Dissociation (allometry)
	d. Dissociation (heterochrony)

Question 81

The shifting of the nose of whales to the top of their head occurs because their upper jaws grow at a much fast rate than their other facial structures. This is an example of what type of developmental process?

Choose one answer.

	a. Duplication and divergence
	b. Co-option
	c. Dissociation (allometry)
	d. Dissociation (heterochrony)

Question 82

What type of developmental constraint has prevented the pronephros from being lost in spite of the fact that it does not serve as a functioning kidney in mammals?

Choose one answer.

	a. Physical
	b. Phyletic
	c. Morphogenetic
	d. Heterochronic

Question 83

What type of developmental constraint restricts the number of ways in which limbs can develop in vertebrates?

Choose one answer.

	a. Physical
	b. Phyletic
	c. Morphogenetic
	d. Heterochronic

Question 84

Which of the following is false in regards to "deep homology"?

Choose one answer.

	a. It suggests that there has been a leap in complexity from invertebrates to vertebrates.
	b. The formation of the central nervous system and the limb are examples of pathways that exhibit it.
	c. When pathways exhibit it, it suggests that there has been only one way in which a particular development process has ever evolved.
	d. It occurs in pathways that not only involve the same proteins but use them for the same function.

Question 85

Which of the following is NOT one of the genes or families of proteins that it is thought the protostome-deuterostome ancestor (PDA) would have?

Choose one answer.

	a. Pax6
	b. Hox genes
	c. Tinman
	d. Dax1

Question 86

Which of the following is NOT one of the reasons why developmental biology has begun to be recognized as being an integral part of the study of evolution?

Choose one answer.

	a. Macroevolutionary events can be studied and explained by examining microevolution.
	b. The evolution of complex structures like the eye is more easily understood when the processes of Pax6 pathways, modularity, and correlated progression are explained.
	c. The environment, as well as genotype, influences an individual's phenotype, and development is the means through which this relationship is mediated.
	d. Homologous genes have been found in very disparate, distantly related organisms.

Question 87

Which stage of development is argued to be the least variable (in terms of what development alterations can occur) and why?

Choose one answer.

	a. The early stage, because changes during that time will dramatically alter the embryo and create non-viable phenotypes.
	b. The early stage, because changes during that time are reversed or halted by developmental-repair factors.
	c. The middle stage, because changes during that time will affect processes of global induction and organogenesis.
	d. The late stage, because changes during that time will only disrupt the normal development of tissues that have already been differentiated.

Question 88

Why is modularity of development an important factor in evolution?

Choose one answer.

	a. Organisms that display modular growth are those that are still in existence today, while those without it only exist in the fossil record.
	b. Because portions of the body are somewhat independent from one another, changes can alter one portion without affecting the entire organism.
	c. Because dramatic evolutionary changes can only occur when several modules are altered, genes that are expressed globally are the likeliest evolutionary candidates.
	d. Modularity is what allows for the sequestration of imaginal discs and the evolution of metamorphosis in insects.

Question 89

What type of developmental constraint has prevented animals from evolving body parts that are moving wheels into which blood circulates?

Choose one answer.

	a. Physical
	b. Phyletic
	c. Morphogenetic
	d. Heterochronic

Question 90

An increase in road usage that led to more vehicle-caused vibrations would most likely cause which of the following?

Choose one answer.

	a. An increase in the number of water fleas (Daphnia) with large head helmets
	b. A higher rate of early hatching in treefrog embryos
	c. A reduction in the number of insects entering diapause
	d. A change in the number of parthenogenetic vs. sexual aphids

Question 91

Because of the effects of environmental chemicals on animal development, some species are used as "bioindicators" to determine the presence or level of pollutants in a particular area. These species are chosen because they are particularly sensitive to a specific compound and/or because the phenotype they exhibit is easily recognizable. If you wanted to know whether water-ways contained high levels of anti-fouling paint material like tributyltin (TBT), what bioindicator species would you choose and what phenotype would you look for?

Choose one answer.

	a. Snails exhibiting "imposex"
	b. Frogs exhibiting sex abnormalities
	c. Salmon exhibiting an inability to develop from parr (freshwater form) to smolt (saltwater form)
	d. Birds exhibiting beak abnormalities and soft eggshells

Question 92

Because of the effects of environmental chemicals on animal development, some species are used as "bioindicators" to determine the presence or level of pollutants in a particular area. These species are chosen because they are particularly sensitive to a specific compound and/or because the phenotype they exhibit is easily recognizable. If you wanted to know whether water-ways contained high levels of nonylphenol, what bioindicator species would you choose and what phenotype would you look for?

Choose one answer.

	a. Snails exhibiting "imposex"
	b. Frogs exhibiting sex abnormalities
	c. Salmon exhibiting an inability to develop from parr (freshwater form) to smolt (saltwater form)
	d. Birds exhibiting beak abnormalities and soft eggshells

Question 93

If juvenile squid (Euprymna scolopes) were raised in the lab in seawater that had been autoclaved (rendered sterile: without living things), what would be true of these squid as adults?

Choose one answer.

	a. They would all be female.
	b. They would not develop functional abdomens.
	c. They would have a small sac behind their mantle, but it would not function as a light organ.
	d. They would have neither a light organ nor a sac designed to house one.

Question 94

In spadefoot-toad tadpoles, environmental factors affect their development in ephemeral pools. Which of the following describes their different morphs?

Choose one answer.

	a. In persistent ponds, tadpoles grow at faster rates and metamorphose sooner.
	b. In ponds that begin drying up, tadpoles metamorphose into larger juveniles.
	c. In ponds that begin drying up, tadpoles increase their assimilation efficiency of algae to speed up metamorphosis.
	d. In persistent ponds, tadpoles grow at normal rates with only a single phenotype and metamorphose later.

Question 95

In spadefoot-toad tadpoles, environmental factors affect their development in ephemeral pools. What particular cue triggers the change in development from one morph to another?

Choose one answer.

	a. Overcrowding
	b. Increasing water temperature
	c. Decreasing oxygen concentration
	d. Proximity to bottom (increasing shallowness)

Question 96

Which of the following compounds appears to interfere with neural-crest migration and initiate the apopotosis of neurons?

Choose one answer.

	a. Retinoic acid (RA).
	b. Quinine.
	c. Ethanol (alcohol).
	d. Caffeine.

Question 97

Which of the following processes has juvenile hormone (JH) NOT been found to influence?

Choose one answer.

	a. Molts (from instar to instar vs. to pupa or eclosion)
	b. The development of queen bees and ants
	c. The development of short-winged or long-winged morphs in locusts
	d. The switch between parthenogenetic and sexual forms in female aphids

Question 98

Which of the following processes have temperature and day-length NOT been found to influence?

Choose one answer.

	a. The development of eyespots in different morphs of African butterflies
	b. The development of queen bees and ants
	c. The development of light-winged and dark-winged morphs of Pieris and Colias butterflies (the cabbage whites and sulphurs)
	d. The switch between parthenogenetic and sexual forms in female aphids

Question 99

You notice that chub minnows in ponds with many trout (predators of chub minnows) have larger tails and are less brightly colored than chub minnows in ponds without trout. You suspect that large tail size and dull colors may be predator-induced defenses. What would you need to demonstrate in order to support your hypothesis?

Choose one answer.

	a. These traits are caused by the presence of trout predators.
	b. These traits are heritable.
	c. Chub with these traits are eaten less.
	d. Both A and C

Question 100

Because of the effects of environmental chemicals on animal development, some species are used as "bioindicators" to determine the presence or level of pollutants in a particular area. These species are chosen because they are particularly sensitive to a specific compound and/or because the phenotype they exhibit is easily recognizable. If you wanted to know whether water-ways contained high levels of agricultural run-off pesticides like RoundUp, what bioindicator species would you choose and what phenotype would you look for?

Choose one answer.

	a. Snails exhibiting "imposex"
	b. Frogs exhibiting sex abnormalities
	c. Salmon exhibiting an inability to develop from parr (freshwater form) to smolt (saltwater form)
	d. Birds exhibiting beak abnormalities and soft eggshells