Chapter 4 Flashcards
What is it when you have the same genes on your two copies of some chromosome?
Homozygous
If you have an unmatched pair of genes you are _ for that gene
Heterozygous
A recessive gene shows its effects only in what condition?
If the gene is homozygous
What genes are present in both sexes but mainly active in one sex? (ex - chest hair on men or breast size on women)
Sex-limited genes
What is a mutation?
A heritable change in a DNA molecule
A heritable change in a DNA molecule
Monozygotic; Dizygotic
The genetic inability to metabolize phenylalanine is known as _
Phenylketonuria
How does a gene influence behavior?
By producing a protein that interacts with the rest of the body chemistry & environment
_ is a change over generations in the frequencies of various genes in a population
Evolution
An action that benefits someone other than the actor is called a/an _
Altruistic behavior
What does a microdeletion remove?
Part of a chromosome
: How does epigenetic change differ from a mutation?
An epigenetic change alters gene activity without replacing it
How does adding a methyl or acetyl group to a histone alter gene activity?
Methyl turns genes off, acetyl accelerates gene activation
What is responsible for evolutionary change in a species?
People with certain genes reproduce more often than average
_ Is the production of new cells
Proliferation
What is the term for the formation of synapses?
Synaptogenesis
The process by which glia produce insulating fatty sheaths that speed transmission in many vertebrate axons is known as _
Myelination
When one of the Sympathetic system’s neurons forms a synapse onto a muscle, that muscle delivers a protein called _ that promotes survival & growth of the axon
Nerve growth factor
A chemical that promotes the survival & activity of a neuron is a _
Neurotrophin
In lab rats, an enriched environment promotes growth in axons & dendrites - Why is this?
Animals are more active in an enriched environment & this exercise promotes growth of axons & dendrites
Musicians cramp is also known as _
Focal hand dystonia
True or false: In old age, many neurons lose some of their synapses & the remaining synapses change slower than before in response to experiences
True
True or false: In early brain development, the muscle movements occur before sensory systems develop
True
Which areas do new neurons develop in during adulthood?
Hippocampus & basil ganglia
If a person is born blind, what happens to the occipital (visual) cortex?
Its cells become responsive to touch or hearing
What causes musicians cramp?
Rewiring of the cerebral cortex
What is the most likely biological explanation for increased risky behavior in adolescents?
Increased activity in brain areas that anticipate reward
What is the most common cause of Alzheimer’s in young people?
Closed head injury/a sharp blow to the head
Temporary interruption of normal blood flow to a brain area is _
A stroke/cerebrovascular accident
What type of stroke is the result of a blood clot or other obstruction in an artery
Ischemia stroke
What type of stroke is the result of a ruptured artery?
Hemorrhage stroke
What are the similarities in the two types of stroke?
Both impair the sodium-potassium pump and lead to edema (fluid accumulation)
What is the difference in the two types of stroke?
In ischemic strokes, neurons deprived of blood lose oxygen & glucose supplies; in hemorrhagic strokes, neurons have extra chemicals
What drug is good for ischemia & breaking up blood clots?
Tissue plasminogen activator (tPA)
How soon after a stroke should a patient receive tPA?
4.5 hours after a stroke
Why is tPA not helpful in cases of hemorrhage?
Hemorrhage strokes result from a ruptured blood vessel, not a blood clot, & tPA breaks up blood clots
After a cell loses input from an axon, what does it secrete to induce other axons to form collateral sprouts?
Neurotrophins
In what species can axons regrow in the spinal cord?
Fish
What is the purpose of dopamine stimulants for a stroke patient?
To combat diaschisis
What can decrease the damage caused by strokes in lab rats but physicians haven’t tried with people?
Decreased body temp & cannabinoids
Where does denervation supersensitivity take place?
At synapses
What causes phantom limb experience?
Reorganization of the sensory cortex
