Deck 4: Genetics, Evolution, Development, and Plasticity

Question 1

 The fluid-filled cavity within the neural tube becomes the central canal of the spinal cord and the four ventricles of the brain.

Answer 1

True

Question 2

 Myelination of the brain and spinal cord is complete by the time of birth.

Answer 2

False

Question 3

 To determine the contributions of heredity and environment, researchers rely mainly on studies of monozygotic and dizygotic twins.

Answer 3

True

Question 4

 The developing infant brain is highly resistant to damage.

Question 5

 The ability of the brain to change its anatomy over time, within limits, is known as ____.

A) plasticity
B) regression
C) connectivity
D) long term potentiation

Question 6

 Sex-linked genes are usually found on the Y chromosome.

Question 7

 Recent evidence suggests that adult vertebrate brains generate new neurons.

Question 8

 Genes become more prevalent in a population if they contribute to reproductive success.

Question 9

 After cells have differentiated as neurons or glia, they ____.

A) differentiate
B) proliferate
C) myelinate
D) migrate

Question 10

 After cells have differentiated as neurons or glia, they migrate.

Question 11

 Proliferation is the ____.

A) production of new cells
B) movement of primitive neurons and glia
C) formation of dendrites and an axon
D) insulation process that occurs on some axons

Question 12

 Synaptogenesis is a process that begins before birth and continues throughout life.

Question 13

 Recent evidence suggests that phantom limb pain is caused by sensations coming from the stump of the amputated limb.

Question 14

 Diaschisis refers to the decreased activity of surviving neurons after damage to other neurons.

Question 15

 Early in development, the nervous system begins as a ____.

A) tube surrounding a fluid-filled cavity
B) spherical structure in the center of the embryo
C) diffuse system of cells scattered throughout the body
D) single layer of cells covering the heart and other internal organs

Question 16

 The most common cause of brain damage in children is closed head injury.

Question 17

 The fluid-filled cavity of the developing neural tube becomes the ____.

A) forebrain
B) midbrain
C) spinal cord
D) ventricular system

Question 18

 Axons are usually formed before the dendrites.

Question 19

 Apoptosis is distinct from necrosis, which is death caused by an injury or a toxic substance.

Question 20

 The damaging effects of a stroke can be limited if treated within a short period of time.

Question 21

 Which of the following best describes the process by which developing axons find their general target areas?

A) Completely random growth
B) Shape attraction
C) Electrical attraction
D) Chemical attraction

Question 22

 What is the process called when a primitive neuron begins to develop dendrites and an axon?

A) Differentiation
B) Migration
C) Myelination
D) Proliferation

Question 23

 Necrosis ____.

A) is a programmed mechanism of cell death
B) is cell death caused by an injury or a toxic substance
C) promotes the survival and growth of dendrites
D) promotes the activity of neurons

Question 24

 The function of neurotrophins is to ____.

A) inhibit proliferation
B) promote survival of axons
C) be used as fuel
D) signal that an axon has been "rejected."

Question 25

 What is signaled by nerve growth factor (NGF)?

A) That a target cell has "accepted" an axon
B) Which target cell a growing axon should connect with
C) That axons should elongate as the body grows bigger
D) The need for new neurons to form in brain areas that are lacking in neurons

Question 26

 Myelination in the human brain ____.

A) is complete upon birth
B) is complete around the second birthday
C) is complete sometime shortly after adolescence
D) continues well into the adult years

Question 27

 Migration requires ____.

A) a precise chemical environment
B) cells which are myelinated
C) mature neurons
D) neurons with fully developed dendrites

Question 28

 Apoptosis ____.

A) is a programmed mechanism of cell death
B) promotes the survival and growth of the axon
C) promotes the survival and growth of dendrites
D) is a programmed mechanism of cell growth

Question 29

 Why is it that every axon in an adult mammal has a target cell (muscle cell or other neuron) with which it makes synaptic contact?

A) Each target cell causes the growth of a neuron and its axon.
B) After formation, axons release a chemical that causes a target cell to form.
C) Axons that fail to find a target cell die.
D) An axon will make contact with any kind of cell and adjust its function as necessary.

Question 30

 After the migrating neuron reaches its destination, ____ begin to form.

A) dendrites
B) axons
C) nuclei
D) ganglions

Question 31

 Roger Sperry cut a newt's optic nerve and rotated the eye. Axons from what used to be the dorsal part of the retina (now located on the ventral side) grew back to the target areas ____.

A) that ordinarily get input from the dorsal retina
B) that ordinarily get input from the ventral retina
C) that ordinarily get input from the center of the retina
D) equally and diffusely

Question 32

 Which of the following are selective as axons form synapses with target cells?

A) Axons, but not target cells
B) Target cells, but not axons
C) Both axons and target cells
D) Neither axons nor target cells

Question 33

 Chemicals in the amphibian tectum guide the growth of axons from the retina to their correct location in the tectum by ____.

A) having dozens of different growth factors
B) using an electrical gradient
C) using a chemical gradient
D) glial cell transportation

Question 34

 Brain cells that are neither neurons nor glia, but which are capable of dividing and then differentiating into neurons or glia, are called ____.

A) parallel fibers
B) intrinsic cells
C) stem cells
D) glomeruli

Question 35

 The concept that neurons refine their many connections based on which ones are most successful is known as ____.

A) natural selection
B) evolution
C) survival of the fittest
D) neural Darwinism

Question 36

 The formation of new synapses is called ____.

A) synaptogenesis
B) differentiation
C) migration
D) fusion

Question 37

 Chemicals known as ____ and ____ guide neuron migration.

A) immunoglobulins; sodium
B) glia; neurothrophins
C) immunoglobulins; chemokines
D) chemokines; neurothrophins

Question 38

 Which of the following best characterizes how axons arrive at the correct target cells?

A) They follow electrical gradients.
B) They follow chemical gradients from the target cell.
C) Axons send out chemicals to the target cells.
D) Target cells send out branches for the axons to follow.

Question 39

 ____ steer new axonal branches and synapses in the right direction.

A) Chemokines
B) Immunoglobulin
C) Glia
D) Neurotrophins

Question 40

 Nerve growth factor (NGF) ____.

A) promotes the survival and growth of the axon
B) is a fuel metabolized by neurons
C) promotes programmed cell death
D) is a hormone first released at puberty

Question 41

 Ischemia is to ____ as hemorrhage is to ____.

A) older individuals; younger individuals
B) proximal; distal
C) obstruction; rupture
D) barely noticeable; lethal

Question 42

 ____ cells proliferate after a stroke.

A) Penumbra
B) Microglia
C) Ischemia
D) Cancer

Question 43

 Which event is the most common cause of a stroke?

A) Lack of glucose
B) Ischemia from an obstruction of an artery
C) Hemorrhage of an artery
D) Blow to the head

Question 44

 In response to nervous system injury, neurotrophins ____.

A) cause the neuron's death
B) reduce inflammation due to this injury
C) increase regrowth of damaged axons
D) promote apoptosis

Question 45

 The mechanism of fetal alcohol syndrome probably relates to ____.

A) overexcited neurons
B) apoptosis
C) decreases apoptosis
D) necrosis

Question 46

 Karl has had a stroke caused by ischemia. His doctors attempted to minimize damage due to the stroke by administering a drug that ____.

A) breaks up blood clots
B) overstimulates neurons in and around the damaged area
C) increases the release of glutamate
D) slows down the sodium-potassium pump

Question 47

 The areas of the cortex used by expert video game players are most likely to ____ than the same cortical areas of those who do not play video games.

A) be thicker
B) have smaller, but a greater number of neurons
C) have faster action potentials
D) be more resistant to transcortical stimulation

Question 48

 Alcohol suppresses the release of ____, the brain's main excitatory neurotransmitter.

A) 5-HT (serotonin)
B) dopamine
C) GABA
D) glutamate

Question 49

 Jasmine is pregnant with her first child. She is curious about how much alcohol, if any, she can drink without worrying about the negative effects on her child?

A) The equivalent of two cocktails a day
B) The equivalent of one beer a day
C) Anything less than what causes her to appear drunk
D) Unknown, and therefore abstention is recommended

Question 50

 Research on laboratory animals indicates that cannabinoids are most effective if taken ____.

A) as soon as the stroke occurs
B) within 20 minutes of the stroke
C) steadily for one month
D) shortly before the stroke

Question 51

 In development, neurotrophins ____. During adulthood, they ____.

A) preserve neurons; produce apoptosis
B) produce apoptosis; increase neuronal branching
C) facilitate differentiation; facilitate migration
D) preserve neurons; increase neuronal branching

Question 52

 An axon that does not receive enough neurotrophins from a target cell will ____.

A) branch out and form other synapses on other cells
B) manufacture its own neurotrophins
C) degenerate and die
D) fail to reabsorb transmitters that have already been released

Question 53

 Which factor appears to be particularly important for branching of neurons during brain development?

A) Engaging in physical activity
B) Playing logic games
C) Having good teachers
D) Having a sterile environment

Question 54

 Closed head injury is ____.

A) the most common cause of brain damage in young adults
B) usually fatal
C) the most common cause of Korsakoff's syndrome
D) related to Alzheimer's disease

Question 55

 A magnetoencephalography study of professional musicians listening to pure tones showed that the musicians had ____.

A) brain responses that were twice as strong as non-musicians
B) slightly less brain responses as non-musicians
C) drastically less brain responses as non-musicians
D) brain responses five times as strong as non-musicians

Question 56

 Closed head injury results in damage partially because of ____.

A) increased production of myelin
B) excessive deficit of neurotrophins
C) rotational forces that push the brain against the inside of the skull
D) infection

Question 57

 Immature neurons experimentally transplanted from one part of the developing cortex to another ____.

A) develop the properties characteristic of their new location
B) maintain the properties of their original location
C) become dysfunctional, with properties of both the original and new locations
D) die

Question 58

 After maturity, the apoptotic mechanisms become ____.

A) hyperactive
B) extinct
C) dormant
D) very complex

Question 59

 What modern day practice helps prevent an inadequate production of thyroid hormones?

A) Fluoride in drinking water
B) Processed sugar
C) Iodized salt
D) Artificial sweeteners

Question 60

 Focal hand dystonia, sometimes called "musician's cramp," is caused by ____.

A) extreme overlap of cortical representation of the fingers
B) deterioration of muscles in the hand
C) demyelination of neurons in the fingers
D) buildup of excess GABA in the temporal cortex

Question 61

 A strand of DNA serves as a template (model) for the synthesis of ____.

A) chromosomes
B) RNA
C) Proteins
D) carbohydrates

Question 62

 Chromosomes consist of large, double-stranded molecules of ____.

A) deoxyribonucleic acid
B) ribonucleic acid
C) autosomal genes
D) recombination genes

Question 63

 One way to relieve the pain associated with a phantom limb is to ____.

A) remove more of the amputated limb
B) have the amputee learn to use an artificial limb
C) stimulate the relevant part of the cortex
D) convince the patient that there is no neural basis for these sensations

Question 64

 Heightened sensitivity to a neurotransmitter after the destruction of an incoming axon is known as ____.

A) axon supersensitivity
B) disuse supersensitivity
C) enervation supersensitivity
D) denervation supersensitivity

Question 65

 What is one impediment to the regeneration of axons in the mammalian central nervous system?

A) Inhibitory chemicals secreted by the damaged portion of the axon
B) Bacterial infections caused by the decaying tissue
C) Glia releasing chemicals that inhibit axon growth
D) Inhibitory messages sent from the cell nucleus when an axon is damaged

Question 66

 A cortical cell originally responded to stimulation of the middle finger. After amputation of that finger, it begins responding to the second and fourth fingers. Which action most likely accounts for this?

A) Synaptic reorganization
B) Growth of completely new axons
C) Altered pattern of blood vessels in the brain
D) A psychotic reaction

Question 67

 After learning strengthens one set of synapses, other synapses ____.

A) weaken
B) die
C) get stronger
D) become aroused

Question 68

 The results of several studies of facial expressions in people who were born blind suggest ____.

A) a minor role for genetics in the control of facial expressions
B) a major role for genetics as well as environment in the control of facial expressions
C) no role of genetics in the control of facial expressions
D) no role of genetics, but a major role of environment in the control of facial expressions

Question 69

 Lola had a stroke several days ago. At this point, which treatment would be most likely to her?

A) Injecting a drug to block dopamine
B) Administering tranquilizers
C) Extensive bed rest
D) Giving stimulant drugs combined with physical therapy

Question 70

 Suppose "A" is a dominant gene for the ability to taste phenylthiocarbamide (PTC) and "a" is a recessive gene for the inability to taste it. Which couples could possibly have both a child who tastes it and a child who does not?

A) father AA, mother aa
B) father Aa, mother AA
C) father Aa, mother Aa
D) father AA, mother AA

Question 71

 Units of heredity that maintain their structural identity from one generation to another are known as ____.

A) enzymes
B) mutations
C) nucleic acids
D) genes

Question 72

 Chemically, what is the route from genes to their expression?

A) DNA to proteins to RNA
B) DNA to RNA to proteins
C) Proteins to DNA to RNA
D) RNA to DNA to proteins

Question 73

 If some of the axons innervating a given cell are destroyed or if they become inactive, what compensatory process takes place in the remaining presynaptic cells?

A) Activation of previously silent synapses
B) Removal of toxins
C) Denervation supersensitivity
D) Collateral sprouting

Question 74

 If most of the axons that transmit dopamine to some brain area die or become inactive, the remaining dopamine synapses become ____.

A) less responsive
B) less easily stimulated
C) more resistant
D) more responsive

Question 75

 A continuing sensation of an amputated body part is called ____.

A) phantom limb
B) ghost limb
C) neuralgia
D) tingling limb

Question 76

 After damage to a set of axons, neurotrophins induce nearby ____.

A) injured axons to form new branches
B) injured dendrites to form new branches
C) uninjured axons to form new branches
D) uninjured dendrites to form new branches

Question 77

 A person with two recessive genes is considered to be ____ for that trait.

A) homozygous
B) heterozygous
C) unitary
D) marginal

Question 78

 Enzymes serve as ____.

A) genetic templates
B) physiological markers of chemical reactions in the body
C) biological catalysts that regulate chemical reactions in the body
D) catalysts for the synthesis of protein molecules

Question 79

 Diaschisis refers to the ____.

A) increase in activity of neurons surrounding a damaged area
B) decreased activity of surviving neurons after other neurons are damaged
C) increased activity in the cerebral cortex after damage to any part of the brain
D) increased activity in the hypothalamus after damage to any part of the brain

Question 80

 A trait not expressed when combined with a dominant trait is called a(n) ____ trait.

A) nurture
B) recessive
C) dominant
D) homozygous