Chapter 4 Flashcards

1
Q

How does new variations are introduced besides the merging of the DNA of your parents?

A

Mutations, recombinations, and microduplications of genes

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2
Q

artificial selection

A

choosing individuals with desired trait and make them the parents of the next generation -> humans (breeders)

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3
Q

Lamarckian evolution

A

You can influence evolution by using or failing to use your body parts (wrong theory)

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4
Q

Does “evolution” mean “improvement”?

A

no, just that the fittest survive. Evolution is not goal directed. Some traits are from situation to situation more or less useful. Maybe they were useful in the past, maybe they will be useful in the future.

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5
Q

Does evolution benefit the individual or the species?

A

Neither: It benefits the genes! In a sense, you don’t use your genes to reproduce yourself. Rather, your genes use you to reproduce themselves

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6
Q

Many people believe the human appendix is useless.
Will it become smaller and smaller with each
generation?

A

No. Failure to need a structure does not make
it smaller in the next generation. The appendix will
shrink only if people with a gene for a smaller appendix
reproduce more successfully than other people do.

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7
Q

Evolutionary psychology

A

concerns how behaviors evolved. The emphasis is on evolutionary and functional explanations

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8
Q

reciprocal altruism

A

the idea that individuals help those who will return the favor. The idea is not just “you scratched my back, so I’ll scratch yours,” but also “you scratched someone else’s back, so I’ll scratch yours.” By helping others, you build a reputation for helpfulness

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9
Q

controversial hypothesis for altruism: group selection

A

altruistic groups thrive better than less cooperative ones. True, but: wouldn’t an uncooperative individual within the cooperative group gain an advantage?

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10
Q

What are plausible ways for possible altruistic genes to spread in a population?

A

Altruistic genes could spread because they
facilitate care for one’s kin or because they facilitate
exchanges of favors with others (reciprocal altruism).
Group selection may also work under some circum-
stances, especially if the cooperative group has some
way to punish or expel an uncooperative individual.

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11
Q

what does a developing baby does first: sensing or moving?

A

moving

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12
Q

Proliferation

A

is the production of new cells.

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13
Q

the five different processes in the development of neurons:

A

proliferation, migration, differentiation,

myelination, and synaptogenesis

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14
Q

Where and what are stem cells?

A

Everywhere, they divide and send the copy (or themselves, does not matter) where it is needed to differentiate there

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15
Q

migration

A

the cells begin to move on particular positions

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16
Q

differentiation

A

Changing into another cell (e.g. an axon or a dendrite)

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17
Q

“While migrating, a cell can already differentiate into an axon.” True or false?

A

True, it can either migrate with its tip still migrating or pushing its tail towards its destination

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18
Q

“While migrating, a cell can already develop its dendrites.” True or false?

A

False, it can already differentiate into an axon, but the dendrites develop when migration ends.

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19
Q

what is myelination and where does it start?

A

the process by which glia produce the insulating fatty sheaths that accelerate transmission in many vertebrate axons. Starting in the spinal cord, then hindbrain, midbrain, and finally forebrain

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20
Q

synaptogenesis

A

the formation of synapses.

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21
Q

Which develops first, a neuron’s axon or its dendrites?

A

The axon forms first.

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22
Q

How to test how old your cells are?

A

Checking the Carbon level. (^14)C corresponds to a certain year, e.g. skin is 1 year old, bones are 15 years old cells

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23
Q

New receptor neurons form in adult rodents for which

sensory system?

A

Olfaction

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24
Q

What evidence indicated that new neurons seldom
or never form in the human cerebral cortex and
olfactory bulb?

A

The (^14)C concentration in the DNA
of human neurons in the cerebral cortex and olfactory
bulbs corresponds to the level during the year the per-
son was born, indicating that all or nearly all of those
neurons are as old as the person is.

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25
Q

Paul Weiss & Roger Sperry

A

Weiss thought axons of detached limbs connect at the place they are and “tune” afterwards so that they send the right information to the brain.
Sperry showed in newt’s that axons, while connecting are attracted by some and repelled by other chemicals and therefore connect just to specific axons

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26
Q

What was Sperry’s evidence that axons grow to a

specific target instead of attaching at random?

A

If he cut a newt’s eye and inverted it, axons grew
back to their original targets, even though the con-
nections were inappropriate to their new positions on
the eye.

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27
Q

How does axons find the right location to bond and connect functional?

A

the chemical gradients steer them approximately (not accurately) to the right location, there the axons forms synapses onto different axons and receives synapses from many. The post synapse strengthens the most appropriate and eliminates others

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28
Q

neural Darwinism

A

In the development of
the nervous system, we start with more neurons and synapses
than we can keep. Synapses form with approximate accuracy,
and then a selection process keeps some and rejects others.
The most successful axons and combinations survive, and
the others fail.

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29
Q

If axons from the retina were prevented from showing
spontaneous activity during early development, what would
be the probable effect on development of the thalamus?

A

The axons would attach based on a chemical gra-
dient but could not fine-tune their adjustment based
on experience. Therefore, the connections would be
less precise.

30
Q

role of the nerve growth factor (NGF) in development of the sympathetic nervous system

A

the sympathetic nervous system forms far more
neurons than it needs. When one of its neurons forms a synapse
onto a muscle, that muscle delivers a protein called nerve
growth factor (NGF) that promotes the survival and growth of
the axon.
An axon that does not receive
NGF degenerates, and its cell body dies.

31
Q

apoptosis and the role of NGF

A

If its axon does not make contact with an appropriate postsynaptic cell by a certain age, the neuron kills itself through a process called apoptosis a programmed mechanism of cell death. NGF cancels the program for apoptosis; it is the postsynaptic cell’s way of telling the incoming axon, “I’ll be your partner. Don’t kill yourself.”

32
Q

neurotrophin

A

E.g. nerve growth factor (NGF) a chemical that promotes the survival and activity of neurons.

33
Q

Are neurotrophins saving axons from apoptosis in the CNS or in the periphery?

A

They are essential for the survival of motor neurons in the periphery.

34
Q

What process assures that the spinal cord has
the right number of axons to innervate all the
muscle cells?

A

The nervous system builds far more neurons than
it needs and discards through apoptosis those that do
not make lasting synapses.

35
Q
What class of chemicals prevents apoptosis in the 
sympathetic nervous system?
A

Neurotrophins, such as nerve growth factor

36
Q

At what age does a person have the greatest number
of neurons—early in life, during adolescence, or during
adulthood?

A

The neuron number is greatest early in life.

37
Q

fetal alcohol syndrome, a condition marked by

A

hyperactivity, impulsiveness, difficulty main-
taining attention, varying degrees of mental retardation,
motor problems, heart defects, and facial abnormalities.

38
Q

Drinking during pregnancy leads to thinning of what brain area?

A

cerebral cortex

39
Q

Anesthetic drugs and anxiety-reducing drugs increase
activity of GABA, decreasing brain excitation. Why would
we predict that exposure to these drugs might be
dangerous to the brain of a fetus?

A

Prolonged exposure to anesthetics or anxiety-
reducing drugs might increase apoptosis of developing
neurons. Increased GABA activity decreases excitation,
and developing neurons undergo apoptosis if they do
not receive enough excitation. Many studies confirm
that anesthetics and anxiety-reducing drugs impair
brain development in laboratory animals, although
the research is less complete for humans

40
Q

In the ferret study, how did the experimenters determine
that visual input to the auditory portions of the brain
actually produced a visual sensation?

A

They trained the ferrets to respond to stimuli on
the normal side, turning one direction in response to
sounds and the other direction to lights. Then they
presented light to the rewired side and saw that the
ferret again turned in the direction it had associated
with lights.

41
Q

Although the central structure of a dendrite becomes stable by adolescence, the peripheral branches of a dendrite

A

remain flexible throughout life

42
Q

An enriched environment promotes growth of axons and
dendrites in laboratory rodents. What is known to be
one mportant reason for this effect?

A

Animals in an enriched environment are more ac-
tive, and their exercise enhances growth of axons and
dendrites.

43
Q

Name two kinds of evidence indicating that touch
information from the fingers activates the occipital
cortex of people blind since birth.

A

First, brain scans indicate increased activity in
the occipital cortex while blind people perform tasks
such as feeling two objects and saying whether they
are the same or different. Second, temporary inactiva-
tion of the occipital cortex blocks blind people’s ability
to perform that task, without affecting the ability of
sighted people.

44
Q

Which brain area shows expanded representation of
the left hand in people who began practicing stringed
instruments in childhood and continued for many years?

A
Somatosensory cortex (postcentral gyrus) of the 
right hemisphere.
45
Q

“musician’s cramp”/ focal hand dystonia

A

stimulation on one finger excites mostly the same corti-
cal areas as another finger. If you cannot clearly feel the difference between one finger and another, it is difficult to move them independently. Furthermore, the motor cortex changes also. One or more fingers may
go into constant contraction.

46
Q

What change in the brain is responsible for musician’s

cramp?

A

Extensive practice of violin, piano, or other instru-
ments causes expanded representation of the fingers
in the somatosensory cortex, as well as displacement
of representation of one or more fingers in the motor
cortex. If the sensory representation of two fingers
overlaps too much, the person cannot feel them sepa-
rately or move them separately.

47
Q

Under what circumstances are adolescents most likely

to make an impulsive decision?

A

Adolescents are most likely to make an impulsive

decision in the presence of peer pressure.

48
Q

When people claim that adolescents make risky
decisions because of a lack of inhibition, which
brain area do they point to as being responsible for
inhibition?

A

The prefrontal cortex

49
Q

What is one way in which older adults compensate for

less efficient brain functioning?

A

Many of them compensate by activating additional

brain areas.

50
Q

closed head injury

A

a sharp blow to the head that does not puncture

the brain. In young people most common cause of brain injury

51
Q

stroke/ cerebrovascular accident

A

A common cause of brain damage, especially in older people,
is temporary interruption of normal blood flow to a brain area
during a stroke, also known as a cerebrovascular accident.

52
Q

ischemia

A

Common type of a stroke: Result of a blood clot or other obstruction in an artery. The neurons deprived of blood lose much of their oxygen and glucose supplies.

53
Q

hemorrhage

A

Less common type of a stroke: Result of a ruptured artery. The neurons are
flooded with blood and excess oxygen, calcium, and other
chemicals.

54
Q

edema

A

Result from a stroke: The accumulation of

fluid, which increases pressure on the brain and the prob ability of additional strokes

55
Q

tissue plasminogen activator (tPA)

A

medicament that help when having an ischema by breaking up the blood cloth. Makes things worse in a hemorrhage

56
Q

two ways that proved to be helpful against a stroke

A

cooling (reduces overstimulation, apoptosis, and inflammation) and cannabinoids (decrease the release of glutamate and exert anti-inflammatory effects)

57
Q

What are the two kinds of stroke, and what causes

each kind?

A

The more common form, ischemia, is the result of
an occlusion of an artery. The other form, hemorrhage,
is the result of a ruptured artery.

58
Q

Why is tPA not helpful in cases of hemorrhage?

A

The drug tPA
breaks up blood clots, and hemorrhage results from
a ruptured blood vessel, not a blood clot.

59
Q

If one of your relatives has a stroke and a well-meaning

person offers a blanket, what should you do?

A

Refuse
the blanket. Recovery will be best if the stroke victim
remains cold.

60
Q

Diaschisis

A

refers to the decreased activity of

surviving neurons after damage to other neurons.

61
Q

After someone has had a stroke, would it be best (if
possible) to direct stimulant drugs to the cells that were
damaged or somewhere else?

A

It is best to direct the amphetamine to the cells
that had been receiving input from the damaged cells.
Presumably, the loss of input has produced diaschisis.

62
Q

colleteral sprouting

A

A surviving axon grows a new branch to
replace the synapses left vacant by a
damaged axon.

63
Q

After a cell loses input from an axon, how does it react (tries to restore it)

A

secretes neurotrophins
that induce other axons to form new branches, or collateral
sprouts, that take over the vacant synapses

64
Q

denervation supersensitivity or receptor supersensitivity

A

If a set of synapses become inactive —perhaps because of damage elsewhere in the brain—the remaining synapses become more responsive, more easily stimulated.

65
Q

how can denervation supersensitivity cause chronic pain?

A

spinal
injury damages many axons, postsynaptic neurons develop
increased sensitivity to the remaining ones. Therefore, even
mild input produces enhanced responses

66
Q

Is collateral sprouting a change in axons or dendritic

receptors?

A

Axons

67
Q

Is denervation supersensitivity a change in axons or

dendritic receptors?

A

Dendritic receptors

68
Q

phantom limb

A

continuing sensation of an amputated body part

69
Q

What is responsible for the phantom limb experience?

A

Synapses that used to receive input from the now
amputated part become vacant. Axons representing
another part of the body take over those synapses.
Now stimulation of this other part activates the syn-
apses associated with the amputated area, but that
stimulation feels like the amputated area.

70
Q

deafferented

A

incurred damage to the sensory nerves
linking a forelimb to the spinal cord, the
animal no longer feels the limb, although the motor nerves still connect to the muscles. We say the limb is deafferented

71
Q

A monkey that loses sensation from one arm stops
using it, but a monkey that loses sensation from both
arms does use them. Why?

A

A monkey that lost sensation in one arm is ca-
pable of moving it, but finds it easier to walk with the
three intact limbs. When both arms lose their sensa-
tions, the monkey is forced to rely on them.