Ch. 4: Genetics, Evolution, Development, Plasticity Flashcards

1
Q

Mendel

A

demonstrated inheritance occurs through genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Genes

A

units of heredity that maintain structural identity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Chromosomes

A

strands of genes that come in pairs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

DNA: Deoxyribonucleic acid

A

composed of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Strand of DNA serves as template model for

A

ribonucleic acid (RNA) molecules, a single-strand chemical. One type of RNA molecule—messenger RNA— serves as a template for the synthesis of protein molecules.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

DNA has 4 bases

A
  1. Adenine
  2. Guanine
  3. Cytosine
  4. Thymine
    The order of those bases determines the order of corresponding bases along an RNA molecule—adenine, guanine, cytosine, and uracil (in RNA and not DNA). The order of bases along an RNA mole- cule in turn determines the order of amino acids that compose a protein.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Some proteins serve as enzymes

A

catalysts that regulate chemical reactions in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Homozygous

A

same genes on your two copies of some chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Heterozygous

A

an unmatched pair of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Dominant gene

A

shows a strong effect in either the homozygous or heterozygous condition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Recessive gene

A

shows its effects only in the homozygous condition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Can single gene produce particular outcome

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Sex linked genes

A

The genes on the sex chromosomes (designated X and Y in mammals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Autosomal genes

A

All other chromosomes are autosomal chromosomes and their genes are

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

You express most of your genes in certain cells and not others

A

changes in the environment can increase/decrease expression of a gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

RNA=

A

1 copy strand of DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Sex limited genes

A

present in both sexes but active mainly in one sex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mutations

A

heritable change in a DNA molecule. Changing just one base in DNA to any of the other three types means that the mutant gene will code for a protein with a different amino acid at one location in the molecule.
Another kind of mutation is a duplication or deletion. During the process of reproduction, part of a chromosome that ordinarily appears once might instead appear twice or not at all. When this process happens to just a tiny portion of a chromosome, we call it a microduplication or microdele- tion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Epigenetics

A

Changes in gene expression. Various experiences can turn a gene on or off. Epigenetic changes can be inherited for a generation or 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Histones

A

Proteins that bind DNA. Histones tighten, stop expression of gene. If they relax, express gene. Adding methyl groups to a promoter turns off a gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Difference b/w mutation and epigenetic change

A

A mutation is a permanent change in part of a chromosome. An epigenetic change is an increase or decrease in the activity of a gene or group of genes. Adding a methyl group turns genes off. An acetyl group loosens histone’s grip and increases gene activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Heritability

A

If the variations in some characteristic depend largely on genetic differences, the characteristic has high heritability. Heritability ranges from zero, indicating no genetic contribution to the variation, to one, indicating complete control.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Monozygotic twins

A

Have the same genes. Not necessarily identical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Dizygotic twins

A

Don’t have same genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Evidence of heritability

A
  1. Twin studies
  2. Children who have been adopted
  3. Candidate gene approach: Studies 1 gene
  4. Genome wide association study: Studies many genes b/w 2 distinct groups
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Estimate of heritability of a trait

A

Specific to a pop at a given time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

PKU

A

genetic inability to metabolize amino acid phenylalanine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Almost every human behavior

A

Has some degree of heritability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Evolution

A

Change over generations in frequencies of various genes in a pop

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

artificial selection

A

plant and animal breeders have long understood this idea, they choose individuals with a desired trait and make them the parents of the next generation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

myth of Lamarckian evolution

A

use or disuse of some structure or behavior cause an evolutionary increase or decrease in that feature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Evolution depends on

A

reproduction, not survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Evolutionary Psychology

A

How behaviors evolved

34
Q

Kin selection

A

selection for a gene that benefits individual’s relatives

35
Q

reciprocal altruism

A

Helping others with the intention of receiving help in return

36
Q

group selection

A

altruistic groups thrive better

37
Q

Homeobox genes

A

regulate expression of other genes and control start of anatomical development, like front and back directions

38
Q

Process of development

A
  1. Fetus develops CNS at 2 weeks old
  2. Dorsal surface thickens, becomes tube and makes hind, mid and forebrain
  3. We start moving before receiving sensations
  4. Infant brain set up to see, hear, and receive sensory info but not how to interpret info (prefrontal cortex slowest to develop)
39
Q

proliferation

A

production of new cells

40
Q

Stem cells

A

Cells that do not become specified for some specific function, can become something else

41
Q

When do most neurons form by

A

Most neurons form within first 28 weeks of gestation, process is stopped by premature birth

42
Q

Early on primitive cells guided by

A

immunoglobulins and chemokines. Deficit in these chemicals leads to impaired migration, decreased brain size and retardation

43
Q

Cell differentiates into

A

neuron, forms dendrites, axons and synapses (synaptogenesis, which begins long before birth but continues throughout life as neurons discard old synapses)

44
Q

Myelination

A

glia produce fatty sheaths that accelerate transmission in vertebrate axons

45
Q

What brain regions can generate new neurons

A

Hippocampus and olfactory bulb

46
Q

Testing carbon in humans has taught us that

A

skin cells are produced rapidly, skeletal cells are 15 years old, hippocampus and basal ganglia (important for learning new tasks) generate new cells every year. Cortex doesn’t generate new cells

47
Q

Growing axon follows chemical path based on

A

what is attracted to and doesn’t follow what it repelled from, leading to its appropriate destination

48
Q

each postsynaptic cell

A

strengthens most appropriate synapses and eliminates others over time

49
Q

Neural darwinism

A

in development of nervous system, we start w/ more neurons and synapses than we can keep, and then selection process keeps some of the synapses and rejects others. Most successful survive and others fail

50
Q

Mutations in genes are

A

random events, but neurotrophins steer new axonal branches and synapses in approx. right direction

51
Q

What determines how many axons survive

A

Muscles

52
Q

Sympathetic nervous system first forms more neurons than it needs

A

When one of its neurons forms a synapse onto a muscle, that muscle delivers a protein called nerve growth factor (NGF), which promotes survival and growth of the axon

53
Q

Axons that don’t receive nerve growth factor (NGF)

A

Degenerate and cell bodies die

54
Q

Apoptosis

A

programmed mechanism of cell death. NGF cancels apoptosis

55
Q

Loss of cells in a particular brain area often indicates

A

Maturation

56
Q

Nerve growth factor is a neurotrophin

A

a chemical that promotes survival and activity of neurons. Essential for growth of axons and dendrites, formation of new synapses, and learning

57
Q

fetal alcohol syndrome

A

Drinking into pregnancy can lead to thinning of cerebral cortex during adulthood

58
Q

Brain neuron must receive input from incoming axons, alcohol inhibits receptors for

A

glutamate, brain’s main excitatory transmitter, and enhances receptors for GABA, main inhibitory transmitter

59
Q

Sensory input instructs cortex about

A

how to develop

60
Q

Far transfer

A

Idea that learning difficult skills will translate to general increase in ability. Has weak effect

61
Q

Just as touch and sound come to activate what would be visual cortex in blind people

A

touch and vision come to activate what would be auditory cortex in deaf people

62
Q

Competing hypotheses

A

practicing a skill reorganizes brain to maximize performance of skill. Other hypothesis is that brain characteristics present from birth lead people to a profession

63
Q

proprioceptive training

A

bursts of vibration towards affected muscles

64
Q

Teenage brain response to rewards is much stronger during teenage years

A

So risky behaviors reflects desire for excitement less than inability to inhibit impulse

65
Q

Frontal cortex begins thinning at age

A

30

66
Q

Closed head injury

A

injury that doesn’t puncture head

67
Q

If a head injury causes confusion and loss of recent memory

A

Duration of this period is strong predictor of long term problems

68
Q

stroke

A

cerebrovascular accident

69
Q

Ischemia

A

Most common type of stroke. Result of blood clot/obstruction in artery

70
Q

Hemorrhage

A

Less common, ruptured artery

71
Q

Edema

A

Accumulation of fluid

72
Q

Ischemia and hemorrhage

A

can lead to edema and dysfunction of sodium-potassium pump

73
Q

Tissue plasminogen activator

A

Breaks up blood clots (P137). Only beneficial for ischemia, and can make hemorrhage worse. Hemorrhage is rare, so tPA often given at hospitals

74
Q

Diaschisis

A

decreased activity in surviving neurons after damage to others

75
Q

After cell loses input from an axon

A

it secretes neurotrophins that induce other axons to form new branches, or collateral sprouts, that take over vacant synapses (P139). If sprouting axons convey similar info as previous axons depends on their particular function

76
Q

Denervation supersensitivity; receptor supersensitivity

A

When one set of synapses strengthen, the others weaken (and vice versa). Helps compensate for decreased input. Can strengthen desirable and undesirable connections, which can lead to things like chronic pain

77
Q

If brain loses incoming axons

A

we can expect denervation supersensitivity, collateral sprouting, or both. Result is either increased response to a synapse that previously produced little effect, or response to an axon that previously didn’t attach at all

78
Q

Phantom limb

A

Brain areas that start as particular body part continue to receive input even if body part is no longer there. Example: if axons representing face come to activate cortical area previously devoted to an amputated hand, touch on face produces facial sensation and sensation in phantom hand

79
Q

Much recovery from brain damage depends on

A

learning to make better use of the abilities you were spared

80
Q

deaferrented limb

A

Lost afferent sensory input