Genetics, Evolution, and Methods
A trait not expressed when combined with a dominant trait is called a(n) ____________ trait.
Recessive
_______________ are a type of glial cell that build myelin.
Oligodendrocytes/Schwann cells
Ions that cannot flow freely across a cell membrane enter a neuron through:
Specialized protein channels
The presynaptic terminal stores high concentrations of neurotransmitter molecules in tiny nearly spherical packets called
Vesicles
A periodic production of action potentials even when the neuron is not stimulated (at rest).
Spontaneous Firing Rate
____________________________ is a technique that uses changes in blood flow and oxygen content to localize parts of the brain that are active during a task.
fMRI
The gap between neurons is called a(n) _____________
synapse
During the rising phase of the action potential, ___________ ions travel into the cell
NA+
a graded depolarization that results from a flow of sodium ions into the neuron; decays in time and space.
EPSP
In the reflex arc, ____________________________ neurons sense touch
Sensory
Recessive genes manifest their effects only when the individual is ____ for them
Homozygous
What part of the neuron receives information?
When stating that the neuron's membrane is polarized, you are referring to a difference in electrical potential between:
The inside and the outside of the membrane.
Fast and focal effects that occur after a neurotransmitter attaches to a receptor on the post-synaptic cell. It triggers change in shape (like paper bag unraveling) and opens a channel. Decays quickly.
Ionotropic Effects
These key findings from studying the reflex arc led to the discovery of the synapse:
1) Reflexes are slower than conduction along an axon
2) There is a cumulative effect
3) Inhibition, which prevents muscles from contracting at the same time
Sherrington's Three Major Observations
Ultimately, a strand of DNA serves as a template (model) for the synthesis of ____.
This law is the principle that if a neuron fires, the resulting action potential is the same regardless of the stimulus that caused it.
All-or-none law
At rest, ____________________________ ions are typically more concentratedinside of the neuron.
K+
Slower and more widespread. Initiates a sequence of metabolic reactions that start slowly but last longer than ionotropic effects. Can alter gene expression and communicate. Known as the "second messenger"
Metabotropic effects
Weak stimuli at the same location that happen close together in time produce a greater response than one of the stimuli by itself. What is this phenomenon called?
Temporal Summation
______ is the study of the change in gene expression without changing the DNA.
Epigenetics
Gaps in the insulating material that surrounds axons are known as:
nodes of Ranvier
The risk of having part of the brain unprotected by the blood-brain barrier is that:
viruses or toxic chemicals are more likely to damage it
Synaptic inputs from separate locations combine their effects on a neuron.
Spatial Summation
After one frog's heart has been stimulated, an extract of fluid from that heart can make a second frog's heart beat faster. What conclusion did Otto Loewi draw from these results?
Transmission at synapses is a chemical event.