1
Q
Gregor Mendel
A
19th century monk who demonstrated that inheritance occurs through genes
2
Q
Genes
A
Units of heredity that maintain their structural identity from one generation to another. Come in pairs
3
Q
Chromosomes
A
Strands of genes. Come in pairs
4
Q
Deoxyribonucleic acid (DNA)
A
- Double-stranded molecule that is part of the chromosomes
- Serves as a template (model) for the synthesis of ribonucleic acid (RNA) molecules
5
Q
Ribonucleic acid (RNA)
A
- A single-strand chemical coded by DNA
- One type serves as a template for the synthesis of protein molecules
- Not all RNA molecules code for proteins. Many RNA molecules perform regulatory functions.
6
Q
Four bases of DNA
A
- Adenine, guanine, cytosine, and thymine
- Any protein consists of some combination of 20 amino acids, in an order that depends on the order of DNA and RNA bases (think coding)
7
Q
Four bases of RNA
A
- Adenine, guanine, cytosine, and uracil
- Any protein consists of some combination of 20 amino acids, in an order that depends on the order of DNA and RNA bases (think coding)
8
Q
homozygous
A
having two identical genes for a given characteristic
9
Q
heterozygous
A
having two unlike genes for a given trait
10
Q
dominant gene
A
gene that shows a strong effect in either the homozygous or heterozygous condition
11
Q
recessive gene
A
one that shows effects only in the homozygous condition
12
Q
sex-linked genes
A
genes on either the X or the Y chromosome
13
Q
autosomal genes
A
Not linked to the X or Y chromosome
14
Q
sex-limited genes
A
Genes that are present in both sexes but that exert their effects primarily in one sex because of activation by androgens or estrogens.
Many sex-limited genes show their effects at puberty.
15
Q
mutation
A
- A heritable change in a DNA molecule by changing one of the bases
- A mutation is rarely advantageous
- Can occur through deletion or duplication.
16
Q
epigenetics
A
- A field that deals with changes in gene expression without modification of the DNA sequence
- Various experiences can turn a gene on or off, such as malnutrition
- Epigenetic changes can be inherited, at least for a generation or two
17
Q
histones
A
- Proteins that bind DNA into a shape that resembles a string wound around a ball
- Histone molecules in the ball have loose ends to which certain chemical groups can attach. To activate a gene, the DNA must partially unwind from the histones.
- Adding a methyl group turns genes off. An acetyl group loosens histone’s grip and increases gene activation.
18
Q
heritability
A
- Estimate of the degree to which variation in a characteristic depends on genetic variations in a given population
- Heritability ranges from zero, indicating no genetic contribution to the variation, to one, indicating complete control
- Study heredity by comparing monozygotic and dizygotic twins, researching virtual twins, and adopted children
19
Q
monozygotic twins
A
twins derived from one egg
20
Q
dizygotic twins
A
twins from two eggs
21
Q
Phenylketonuria (PKU)
A
- A genetic inability to metabolize the amino acid phenylalanine. If PKU is not treated, phenylalanine accumulates to toxic levels, impairing brain development.
- Although PKU is a hereditary condition, environmental interventions can modify it - physicians advise the parents to put the baby on a strict low-phenylalanine diet to protect the brain
22
Q
Evolution
A
- change over generations in the frequencies of various genes in a population
23
Q
artificial selection
A
- process of selecting plants/animals for desired traits
24
Q
Lamarckian evolution
A
- Discredited hypothesis that the use or disuse of some body part will increase or decrease its size in the next generation, known as “inheritance of acquired characteristics”
25
Evolutionary psychology
field that deals with how behaviors evolved
26
kin selection
Hypothesis 1 for altruism: selection for a gene that benefits the individual’s relatives
27
reciprocal altruism
Hypothesis 2 for altruism: helping others who may be helpful in return
28
group selection
Hypothesis 3 for altruism: evolutionary selection favoring a gene because of its benefits to a group
29
homeobox genes
- Regulates the expression of other genes and controls the start of anatomical development
30
Proliferation
production of new cells
31
stem cells
undifferentiated cells that divide and produce daughter cells that develop more specialized properties
32
immunoglobulins
Chemicals that guide neuron migration
33
Chemokines
Chemicals that guide neuron migration
34
Differentiation
As a cell differentiates into a neuron, it begins to form its dendrites, axon, and synapses
35
Synaptogenesis
the formation of synapses, begins long before birth, but it continues throughout life, as neurons form new synapses and discard old ones. The process generally slows in older people
36
myelination
the process by which glia produce the insulating fatty sheaths that accelerate transmission in many vertebrate axons.
Myelin forms first in the spinal cord and then in the hindbrain, midbrain, and forebrain. Myelination continues gradually for decades and increases as a result of learning a new motor skill
37
Exceptions to neurons later in life
- Olfactory receptors - restores exposed cells to the outside world and to toxic chemicals
- Hippocampus - A supply of new neurons keeps the hippocampus “young” for learning new tasks. we replace almost 2 percent of neurons in that area per year.
- Basal ganglia
- The two areas where we make new neurons throughout life, are both important for new learning
38
How to Axons grow/find the right location
A growing axon follows a path of cell surface molecules, attracted by certain chemicals and repelled by others, in a process that steers the axon in the correct direction.
each axon forms synapses onto many cells in approximately the correct location, and each target cell receives synapses from many axons. Over time, each postsynaptic cell strengthens the most appropriate synapses and eliminates others
39
neural Darwinism
we start with more neurons and synapses than we can keep, and then a selection process keeps some of the synapses and rejects others
40
nerve growth factor (NGF)
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 that promotes the survival and growth of the axon. An axon that does not receive NGF degenerates, and its cell body dies
41
apoptosis
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
42
neurotrophin
- a chemical that promotes the survival and activity of neurons
- essential for growth of axons and dendrites, formation of new synapses, and learning
43
Gastrulation
early stages of embryological development vulnerable to malnutrition, toxic chemicals, and infections, such as FASD
44
Fetal Alcohol Syndrome
Drinking during pregnancy leads to thinning of the cerebral cortex.
At the earliest stage of pregnancy, it interferes with neuron proliferation. A little later, it impairs neuron migration and differentiation. Still later, it impairs synaptic transmission.
When alcohol leaves, glutamate overexcites its receptors, bringing excess sodium and calcium into the cell and poisoning the mitochondria
45
Far transfer
Improvement of a skill due to practice at a dissimilar skill. Eg. doing sudoku to improve overall brain activity. Shows little improvement beyond making the person good at sudoku.
46
Focal Hand Dystonia (Musician's cramp)
- A disorder where one or more fingers is in constant contraction or where moving one finger independently of others is difficult
- The brain overly represents one of the fingers in the motor cortex causeing and overlapping and displacing ot he other fingers
47
Impulsiveness in Adolescents
- the prefrontal cortex is not fully formed, however, this is not the sole reason
- the brain’s response to rewards, especially anticipation of rewards, increases strongly during the teenage years
48
Aging in the brain
- The thickness of the temporal cortex shrinks by about half a percent per year, starting at age 30
- Brains can compensate for decrease arousal in 1 or 2 areas by using widespread areas
49
Closed head injury
- result of a sharp blow to the head that does not puncture the brain CNS
- Most common cause of brain damage in young people
- Risks for damage include rotation force and blood clots
50
Cerebrovascular Accident
- Result of interrupted blood flow to the brain resulting from either a blood clot or a ruptured artery
- Common cause of brain damage from a stroke
51
Ischemia
- Type of stroke resulting from a blood clot or other obstruction in an artery
- Neurons lose oxygen and glucose supplies
- Can lead to edema
- Impairs the sodium-potassium pump
52
Hemorrhage
- Type of stroke resulting from a ruptured artery
- Neurons are flooded with excess oxygen, calcium, and other chemicals
- Can lead to edema
- Impairs the sodium-potassium pump
53
Edema
- Accumulation of fluid EEG, which increases pressure on the brain and the probability of additional strokes
54
Tissue Plasminogen Activator (tPA)
- Drug that breaks up blood clots, used as a treatment within 4.5 hours of a stroke
- Is helpful for ischemia but can worsen a hemorrhage
55
Diaschisis
- Decreased activity of surviving neurons after damage to other neurons
- Stimulation can help if this results in behaviour changes
56
Damaged axons
Damaged axons in the peripheral nervous system do grow back at a rate of about 1 mm per day, following its myelin sheath to the original target.
Do not grow back in the brain or spinal cord
Requires significant practice (motor or sensory) to restore function
57
Collateral Sprouting
- After a cell loses input from an axon, it secretes neurotrophins that induce other axons to form new branches
- the result depends on whether the sprouting axons convey information similar to those that they replace
58
denervation supersensitivity
- Increased sensitivity to neurotransmitters by a postsynaptic neuron after loss of input
- Helps to compensate for decreased input
- Can sometimes be responsible for undesirable connections such as increased pain
59
Limb amputation
- the stretch of cortex previously responsive to that limb was now responsive to the face or perhaps axons from the face were already present but became stronger through denervation supersensitivity
- The cells that previously responded to arm stimulation now receive information from the face
60
Phantom Limb
- A continuing sensation of an amputated body part
- axons representing the face come to activate the cortical area previously devoted to an amputated hand
- Many amputees who learn to use an artificial arm report that their phantom sensations gradually disappear
61
Deafferented
to remove or disable the sensory nerves from a body part
Psych 302
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