Deck 9: Development of the Nervous System

Question 1

The neural plate is a patch of

A) multipolar neurons.
B) ectoderm.
C) mesoderm.
D) endoderm.
E) growth cones.

Answer 1

ectoderm.

Question 2

Neural tube cells migrate radially

A) along axons of other cells.
B) along special glial cells.
C) to the ventricular zone.
D) all of the above
E) both B and C

Answer 2

along special glial cells.

Question 3

Immature cells that have the potential to develop into various kinds of mature cells are called

A) ependymal cells.
B) multipotent cells.
C) ventricular cells.
D) radial cells.
E) branch cells.

Answer 3

multipotent cells.

Question 4

The very first cells to develop in the embryo are

A) multipolar.
B) bipolar.
C) myelinated.
D) totipotent.
E) mesodermal.

Question 5

The neural groove develops into the neural

A) tube.
B) plate.
C) mesoderm.
D) endoderm.
E) cord.

Question 6

Cells of the neural plate are

A) ectodermal.
B) totipotent.
C) multipotent.
D) both A and B
E) both A and C

Question 7

The neural plate develops directly into the

A) neural tube.
B) neural groove.
C) brain.
D) CNS.
E) PNS.

Question 8

Stem cells are cells that

A) are multipotent.
B) have a seemingly unlimited capacity to multiply.
C) are multipolar.
D) both a and B
E) both B and C

Question 9

Embryonic cells that have the potential for unlimited renewal and have the ability to develop into different kinds of mature cells if they are transplanted to different sites are often called

A) daughter cells.
B) embryonic stem cells.
C) zygotes.
D) multipolar cells.
E) ectodermal cells.

Question 10

The process of the growth of a fertilized egg into a mature nervous system is called

A) neural growth.
B) neuroplasticity.
C) neurodevelopment.
D) psychological development.
E) rewiring.

Question 11

Most cell division in the developing neural tube occurs in the

A) hindbrain zone.
B) ventricular zone.
C) ventricles.
D) posterior zone.
E) subventricular zone.

Question 12

By 40 days after conception, swellings are clearly visible at the anterior end of the neural tube.There are

A) 2.
B) 3.
C) 4.
D) 32.
E) 64.

Question 13

Most neural proliferation occurs in the layer of the neural tube that is adjacent to

A) the fluid-filled central canal.
B) the cortex.
C) the marginal zone.
D) layer 6.
E) the neural crest.

Question 14

Totipotential means that a developing cell

A) is capable of developing into any type of cell in the organism.
B) is totally committed to one cell for life.
C) cannot divide.
D) is totally developed and will not differentiate.
E) is entirely potent in excitation or inhibition.

Question 15

After the formation of the neural tube, the number of cells destined to become part of the adult nervous system

A) actually declines.
B) stays the same until the end of the neural-plate phase.
C) stays the same until the end of the neural-groove phase.
D) increases rapidly.
E) doubles and then stays the same until birth.

Question 16

The first major phase of neurodevelopment is induction of the

A) neural tube.
B) neural grove.
C) growth cones.
D) neural plate.
E) neural growth factors.

Question 17

At 18 days after conception, this structure is visible in the developing embryo: the neural

A) groove.
B) tube.
C) plate.
D) floor.
E) crest.

Question 18

A zygote divides to form

A) a sperm cell and an ovum.
B) two ova.
C) two zygotes.
D) two daughter cells.
E) two sperm cells.

Question 19

By 40 days after conception, three swellings become visible at the anterior end of the human neural tube.The most anterior of these swellings eventually develops into the

A) brain.
B) midbrain.
C) hindbrain.
D) forebrain.
E) ventricles.

Question 20

The case of Genie emphasizes the role of

A) the brain in behavior.
B) experience in human neural and psychological development.
C) the brain in language.
D) language in learning.
E) neuroplasticity in development.

Question 21

Research on the migration of future neocortical neurons has made one important point: __________ is everything.

A) Timing
B) Location
C) Genetics
D) Experience
E) Age

Question 22

Only those growth cones that are not pioneer growth cones can normally find their way to their targets by

A) chemoaffinity.
B) fasciculation.
C) blueprints.
D) topographic gradients.
E) stopping at a service station and asking for directions.

Question 23

The neural crest

A) is anterior to the neural tube.
B) is the bottom of the neural tube.
C) develops into the hindbrain.
D) develops into the PNS.
E) develops into the spinal cord.

Question 24

During the formation of the neural tube, a few cells break off from the neural plate and form a structure that lies dorsal to the tube.This structure is the neural

A) groove.
B) canal.
C) crest.
D) zone.
E) layer.

Question 25

In frogs, salamanders, and other simple vertebrates, retinal ganglion cells project primarily to the

A) thalamus.
B) tectum.
C) tegmentum.
D) cerebellum.
E) visual cortex.

Question 26

The pattern of migration of future neocortical neurons is referred to as

A) accelerated.
B) insidious.
C) inside out.
D) subventricular.
E) ependymal.

Question 27

At the tip of each growing axon or dendrite is an amoeba-like process called

A) an amoeba cell.
B) a growth cone.
C) a pioneer cell.
D) a blueprint cell.
E) a growth cell.

Question 28

In addition to the radial migration of developing neurons, there is considerable __________ migration.

A) rapid
B) tangential
C) intermediate
D) circuitous
E) axonal

Question 29

In Sperry's classic studies of eye rotation and regeneration of the optic nerves, he assessed the visual capacities of his subjects by assessing their ability to

A) strike accurately at fly-like stimuli.
B) identify colors.
C) perform a visual discrimination task.
D) detect the presence of dim lights.
E) solve maze problems.

Question 30

Cell adhesion molecules are thought to mediate

A) differentiation.
B) aggregation.
C) proliferation.
D) sprouting.
E) cell death.

Question 31

Sperry's initial version of the chemoaffinity hypothesis of axon growth has difficulty accounting for

A) the results of Sperry's own eye-rotation regeneration experiments.
B) the ability of axons to grow to their correct targets.
C) the ability of axons to follow exactly the same circuitous route to their target in every member of a species.
D) all of the above
E) both A and B

Question 32

There seem to be two different mechanisms of neural migration: glial-mediated migration and

A) amoeboid migration.
B) somal translocation.
C) pioneer migration.
D) growth cone translocation.
E) neural cresting.

Question 33

Frogs, unlike mammals, have retinal ganglion cells that are capable of

A) degeneration.
B) proliferation.
C) color vision.
D) regeneration.
E) aggregation.

Question 34

Which of the following are amoeba-like in their appearance and movements?

A) growth cones
B) ependymal cells
C) neural cell-adhesion molecules
D) radial glial cells
E) retinal ganglion cells

Question 35

The pattern of neural migration that is indicated by the arrows in this illustration is

A) radial.
B) tangential.
C) inside out.
D) outside in.
E) posterior.

Question 36

Sperry's experiments on eye-rotation in frogs led to an influential hypothesis that explains how growth cones find their way to their targets: the

A) radial glial hypothesis.
B) cell-adhesion hypothesis.
C) chemoaffinity hypothesis.
D) all of the above
E) both A and B

Question 37

The neural crest develops into the

A) ventricular system.
B) cortex.
C) peripheral nervous system.
D) circulatory system of the brain.
E) neural tube.

Question 38

At 24 days after conception, the precursor of the PNS is visible in the developing embryo.This structure, which is illustrated here, is the neural

A) tube.
B) plate.
C) crest.
D) groove.
E) stem.

Question 39

Growth cones extend and retract finger-like cytoplasmic extensions as if they were feeling their way.These extensions are called

A) adhesion digits.
B) growth cone adhesion digits.
C) filopodia.
D) pseudopodia.
E) siphons.

Question 40

The first growth cone of a developing tract to reach the target is called a __________ growth cone.

A) fast
B) pioneer
C) quick
D) early
E) premier

Question 41

Between birth and adulthood, the size of the human brain

A) doubles.
B) quadruples.
C) actually declines.
D) stays the same.
E) increases 10 fold.

Question 42

If an optic nerve of a mature frog is transected and half of the associated retina is destroyed,

A) the axons grow out from the retinal ganglion cells in the remaining half of the retina to their original targets on the optic tectum.
B) the destroyed retina regenerates and then axons grow out from the complete retina and innervate the optic tectum in the species-typical fashion.
C) the axons grow out from the remaining retinal ganglion cells to targets systematically distributed over the entire optic tectum.
D) half of the optic tectum degenerates.
E) both A and D

Question 43

Apoptosis is safer than necrosis because apoptosis does not involve

A) neuron death.
B) inflammation.
C) suicide.
D) degeneration.
E) synapse rearrangement.

Question 44

Neurotrophins

A) are life-preserving chemicals for neurons.
B) are supplied to neurons by their targets.
C) promote neuron death.
D) both A and B
E) both B and C

Question 45

The general effect of synapse rearrangement is to

A) increase the number of different target cells innervated by each neuron.
B) increase the number of synaptic contacts received by each neuron.
C) focus the output of each neuron on fewer postsynaptic cells.
D) increase the ratio of axosomatic synapses to axodendritic synapses.
E) increase the number of synapses.

Question 46

In vitro, neurons will form synapses

A) only with their correct targets.
B) only with neurons of the same type.
C) with almost any neuron.
D) only with glial cells.
E) only with the correct glial cells.

Question 47

With a few exceptions, all of the neurons that will compose the adult human brain have developed and are in their appropriate location by the

A) sixth day of prenatal development.
B) sixth week of prenatal development.
C) third month of prenatal development.
D) seventh month of prenatal development.
E) early teens.

Question 48

The human brain grows after birth because of

A) synaptogenesis.
B) myelination.
C) increased dendritic branching.
D) all of the above
E) none of the above

Question 49

Evidence suggests that many neurons die during development because of

A) faulty growth cones.
B) their inability to compete successfully for their target's neurotrophins.
C) genetic deformations.
D) metabolic excess.
E) synapse rearrangement.

Question 50

When it comes to synaptogenesis, neurons display a substantial degree of

A) specificity.
B) promiscuity.
C) monogamy.
D) faithfulness.
E) inertia.

Question 51

In support of the topographic-gradient hypothesis, it has been shown that

A) axons do not grow out from the retinas until the retinas are fully grown, which is why babies have disproportionately large eyes.
B) axons do not grow out from the retinas until their target structures (e.g., optic tectums) are fully grown.
C) retinas and optic tectums always grow in precise proportion to one another.
D) the synaptic connections originally formed by retinal ganglion cells on the optic tectums gradually shift as both the eyes and optic tectums grow at different rates during development.
E) both A and B

Question 52

Neuron death

A) starts to occur in humans around the age of 50.
B) is a stage of normal early neural development.
C) is rare in healthy humans until after puberty.
D) is a common, but unfortunate, consequence of accidental exposure to neural gradients.
E) is always followed by regeneration.

Question 53

Eyes and optic tectums grow at different rates.As they grow, the synaptic connections that were originally formed on the tectum by axons of retinal ganglion cells shift so that the retina is always fully and faithfully mapped on the tectum.This finding supports the

A) chemoaffinity hypothesis.
B) pioneer hypothesis.
C) topographic-gradient hypothesis.
D) all of the above
E) both A and C

Question 54

Synaptic density in the primary visual cortex of infants

A) is maximal by the seventh or eighth postnatal month, and then it declines.
B) reaches adult levels by the seventh or eighth prenatal month.
C) follows the same course of development as the myelination of prefrontal cortex.
D) both A and C
E) both B and C

Question 55

Most of the cell death associated with early development of the brain is

A) necrotic.
B) passive.
C) apoptotic.
D) both A and B
E) both B and C

Question 56

A recent finding is that synaptogenesis depends on the presence of

A) astrocytes.
B) neurons.
C) growth cones.
D) pioneer cones.
E) guidance molecules.

Question 57

Less is known about synapse formation than axon growth because synapse formation requires

A) fasciculation.
B) coordinated activity in at least two cells.
C) growth cones.
D) guidance molecules.
E) regeneration.

Question 58

The development of the human brain is unique in that

A) there is no early cell death.
B) there is no early reorganization.
C) it develops so slowly.
D) it develops so quickly.
E) the PNS develops before the CNS.

Question 59

Neurotrophins can

A) promote neuron growth.
B) promote neuron survival.
C) function as axon guidance molecules.
D) all of the above
E) both A and B

Question 60

The postnatal growth of the human brain results from

A) synaptogenesis.
B) an increase in the number of neurons.
C) myelination.
D) all of the above
E) both A and C

Question 61

Several studies have shown that early music training increases the size of the

A) auditory cortex that responds to complex musical tones.
B) right hemisphere.
C) auditory cortex that responds to pure tones.
D) brain.
E) auditory cortex.

Question 62

Functions of the prefrontal cortex include

A) working memory.
B) planning and carrying out sequences of action.
C) locating objects in space.
D) all of the above
E) both A and B

Question 63

In an experiment by Diamond, perseverative errors were made by

A) infant monkeys.
B) infant monkeys with hippocampal damage.
C) adult monkeys with bilateral lesions of dorsolateral prefrontal cortex.
D) all of the above
E) both A and C

Question 64

Perseveration is the tendency to

A) form long-term working memories.
B) form permanent short-term memories.
C) continue making formerly correct responses that are currently incorrect.
D) continue making formerly incorrect responses that are currently correct.
E) fasciculate in private.

Question 65

If just one eye is deprived of input early in life,

A) the contralateral visual cortex totally degenerates, but the ipsilateral visual cortex does not.
B) there is a decrease in the number of visual cortex neurons that can be activated by stimulation of the early-deprived eye.
C) there is an increase in the number of visual cortex neurons that can be activated by stimulation of the nondeprived eye.
D) both A and B
E) both B and C

Question 66

Early monocular deprivation

A) eliminates ocular dominance columns.
B) decreases the width of ocular dominance columns from the deprived eye.
C) increases the width of ocular dominance columns from the nondeprived eye.
D) causes ocular dominance columns to develop sooner.
E) both B and C

Question 67

The first evidence that new neurons can be created in the brains of adult animals came in the early 1980s from the study of

A) the hippocampus.
B) the olfactory bulbs.
C) songbirds.
D) hamsters.
E) the amygdala.

Question 68

Knudsen and Brainard (1991)raised barn owls with vision-displacing prisms over their eyes.This led to the ontogenetic development of

A) a corresponding shift in the auditory topographic map in the tectum.
B) a discrepancy between where a stimulus was heard to be and where it was seen to be.
C) the degeneration of the tectum.
D) the degeneration of the visual tectum.
E) the degeneration of the auditory cortex.

Question 69

In comparison to the cortices of rats that had been reared in enriched environments, the cortices of rats that had been reared by themselves in barren cages

A) were thinner.
B) had less dendritic development.
C) had fewer synapses per neuron.
D) all of the above
E) none of the above

Question 70

The prefrontal cortex seems to play a role in

A) working memory.
B) planning and carrying out sequences of action.
C) inhibiting responses that are inappropriate in the current situation.
D) all of the above
E) both A and B

Question 71

The disruptive effects of total visual deprivation of the left eye on subsequent vision through the left eye are greater when the

A) right eye is deprived at the same time.
B) deprivation occurs early in life.
C) right eye is not deprived at the same time.
D) both A and B
E) both B and C

Question 72

Perseverative errors are often made by children between the ages of

A) 3 to 5 months.
B) 7 to 12 months.
C) 1 to 2 years.
D) 2 to 4 years.
E) 4 to 8 years.

Question 73

How long does one eye have to be totally deprived of stimulation early in life in order to produce significant reductions in the proportion of visual cortex neurons that can be activated by stimulation of the deprived eye?

A) a few days
B) a few hours
C) a few minutes
D) a few weeks
E) a few months

Question 74

A few days of early monocular deprivation produces a massive decrease in the axonal __________ of lateral geniculate nucleus neurons that normally conduct signals from the deprived eye.

A) branching
B) regeneration
C) width
D) layers
E) degeneration

Question 75

Roe and his colleagues (1990)caused the developing axons of ferret retinal ganglion cells to synapse in the medial geniculate nuclei of the auditory system.Once the ferrets matured, their

A) auditory cortex responded to visual stimuli.
B) auditory cortex was laid out retinotopically.
C) thalamus had totally degenerated.
D) both A and B
E) both A and C

Question 76

Neurons and synapses that are not activated by experience usually

A) develop more slowly.
B) develop more quickly.
C) develop abnormally.
D) do not survive.
E) become more responsive.

Question 77

Studies have shown that about __________ new neurons are created each hour in the hippocampus of adults?

A) 4
B) 8
C) 50
D) 100
E) 2,000

Question 78

It is now generally acknowledged that adult brains are

A) set in their own ways.
B) capable of major adaptation.
C) not as plastic as developing brains.
D) both B and C
E) none of the above

Question 79

In mammals, adult neurogenesis occurs in the

A) hippocampus.
B) olfactory bulb.
C) amygdala.
D) all of the above
E) both A and B

Question 80

The course of human cognitive development is thought to reflect development in the

A) prefrontal cortex.
B) hippocampus.
C) secondary neocortex.
D) posterior parietal cortex.
E) hypothalamus.