brain and behavior ch 4

DNA to RNA to proteins

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

immunoglobulins, chemokines

Chemicals known as ____ and ____ guide neuron migration.

breaks up blood clots

Damage due to stroke caused by ischemia can be minimized by administering a drug that ____.

tube surrounding a fluid-filled cavity

Early in development, the nervous system begins as a ___

through diet

How is it possible to prevent the intellectual disabilities that are generally associated with PKU?

preserve neurons, increase neuronal branching

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

obstruction, rupture

Ischemia is to ____ as hemorrhage is to ____.

continues well into the adult years

Myelination in the human brain___

promotes the survival and growth of the axon

Nerve growth factor (NGF) ____

that ordinarily get input from the dorsal retina

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 into the target areas ___

father Aa, mother Aa

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

be thicker

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

neural Darwinism

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

true

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

That a target cell has "accepted" an axon

What is signaled by nerve growth factor (NGF)?

chemical attraction

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

axons that fail to find a target cell die

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?

ischemia

___ cells proliferate after a stroke

neurotrophins

____ steer new axonal branches and synapses in the right direction

phantom limb

a continuing sensation of an amputated body part is called ___

synaptic reorganization

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 sex-limited

a gene is found that controls the age at which a man grows bald, if at all. that gene seldom affects women, even if they have the gene. what kind of gene is this most likely to be?

homozygous

a person with two recessive genes is considered to be ___ for that trait.

RNA

a strand of DNA serves as a template (model) for the synthesis of ___

recessive

a trait not expressed when combined with a dominant trait is called an ___ trait

migrate

after cells have differentiated as neurons or glia, they ___

true

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

uninjured axons to form new branches

after damage to a set of axons, neurotrophins induce nearby__

weaken

after learning strengthens one set of synapses, other synapses ___

dormant

after maturity, the apoptotic mechanisms become ___

dendrites

after the migrating neuron reaches its destination, ___ begins to form.

glutamate

alcohol suppresses the release of ___, the brains main excitatory transmitter

brain responses that were twice as strong as non-musicians

an MEG study of professional musicians listening to pure tones showed that professional musicians had ___

on any chromosome other than the X or Y chromosome

an autosomal gene is a gene ___

degenerate and die

an axon that does not receive enough neurotrophins from a target cell will ___

color vision deficiency

an example of a sex-linked trait is ___

a given population

any estimate of the heritibility pf a particular trait is specific to ___

is a programmed mechanism of cell death

apoptosis ___

true

apoptosis is distinct from necrosis, which is death caused by an injury or toxic substance

true

axons are usually formed before the dendrites

stem cells

brain cells that are neither neurons nor glia, but which are capable of dividing and then differentiating into neurons or glia, are called ___

artificial selection

breeding some animals selectively because the possess some desirable characteristic is called ___

mutations

changes in single genes are called ___

using a chemical gradient

chemicals in the amphibian tectum guide the growth of axons from the retina to their correct location in the tectum by ___

deoxyribonucleic acid

chromosomes consist of large, double-stranded molecules of ___

the most common cause of brain damage in young adults

closed head injury is ___

rotational forces that push the brain against the inside of the skull

closed head injury results in damage partially because of ___

decreased activity of surviving neurons after other neurons are damaged

diaschisis refers to the ___

true

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

biological catalysts that regulate chemical reactions in the body

enzymes serve as ___

the number of copies of one's genes that endure in later generations

evolution improves the fitness of the population, which is defined as ___

extreme overlap of cortical representation of the fingers

focal hand dystonia, sometimes called "musician's cramp", is caused by ___

the differences must have a hereditary basis

for natural selection to generate evolutionary change in a population ___

true

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

denervation supersensitivity

heightened sensitivity to a neurotransmitter after the destruction of an incoming axon is known as ___

Unknown, and therefore abstention is recommended

how much alcohol, if any, can a pregnant woman drink without worrying about the negative effects on her child?

the environment may possibly influence that trait

if a trait has high hertibility, ___

more responsive

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

collateral sprouting

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?

develop the properties characteristic of their new location

immature neurons experimentally transplanted from one part of the developing cortex to another ___

the X chromosome

in general, biologists who speak of sex-linked genes are typically referring to genes on ___

increase regrowth of damaged axons

in response to nervous system injury, neurotrophins ____

foods high in phenylalanine

individuals afflicted with PKU need to avoid ___

false

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

a precise chemical environment

migration requires ___

is the cell death caused by an injury or toxic substance

necrosis ___

adopted children will closely resemble their biological parents

on a given trait, high heritability suggests that ___

have the amputee learn to use an artificial limb

one way to relieve the pain associated with a phantom limb is to __

production of new cells

proliferation is the ___

true

recent evidence suggests that adult vertebrate brains generate new neurons.

false

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

shortly before the stroke

research on laboratory animals indicates that cannabinoids are most effective if taken___

any chromosomes

sex-limited genes are found on ___

false

sex-linked genes are usually found on the Y chromosome

heritability of this trait is high

suppose that adopted children are more similar to their biological parents than their adoptive parents in their preferences for a flavor of ice cream. which statement is true in this circumstance?

true

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

plasticity

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

true

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

false

the developing infant brain is highly resistant to damage

ventricular system

the fluid-filled cavity of the developing neural tube becomes the ___

synaptogenesis

the formation of new synapses is called ___

promote survival of axons

the functions of neurotrophins is to ___

apoptosis

the mechanism of fetal alcohol syndrome probably relates to ___

true

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

a major role for genetics as well as environment in the control of facial expressions

the results of several studies of facial expressions in people who were born blind suggest ___

true

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

genes

units of heredity that maintain their structural identity from one generation to another are known as ___

glia releasing chemicals that inhibit axon growth

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

differentiation

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

iodized salt

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

ischemia from an obstruction of an artery

which event is the most common cause of a stroke?

engaging in physical activity

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

both axons and target cells

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

they follow chemical gradients from the target cell

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

"if you don't use it, you lose it"

which of the following represents Lamarckian evolution?

XX

which pair of sex chromosomes is found in a normal male mammal?

sex-limited genes become activated

which statement best explains why males can grow breasts under certain hormonal conditions?

evolutionary success is assessed by the number of one's offspring surviving to reproduce

which statement is true with respect to evolution?

Giving stimulant drugs combined with physical therapy

which treatment would be most likely to help a patient starting it several days after a stroke?

unmetabolized amino acids accumulate and affect the brain

why do children with PKU develop intellectual disabilities?