Evolution
What mechanisms result in evolution? List at least 3 of 4.
Mutation, genetic drift, natural selection, gene flow
What is the range of conditions—like type of food—a species needs to survive (often constrained by competition)
niche
What type of signaling occurs within a cell and what type of signaling transfers information to other neurons?
Electrical signaling; chemical signaling
What are the two sections of the nervous system and what do they encompas?
The central nervous system: brain and spinal cord.
The peripheral nervous system: all other neurons in the body.
What is the resting voltage of a neuron?
What voltage sends the action potential from depolarization to repolarization?
-70mV
40mV
How is genetic drift affected by population size?
More drastically with smaller population sizes, while its effects are lessened in larger populations.
What is the effect of genetic drift and natural selection on genetic variation within a population?
Both tend to decrease diversity
What part of the neuron receives the chemical signal (neurotransmitter)?
The dendrites
A large molecule requires a channel protein to cross the membrane into a cell down its concentration gradient. What type of transport is this?
Passive transport for diffusion of the molecule
A population of squirrels is given a medication and suddenly has the ability to jump very far from tree to tree. They are able to acquire more food and survive longer because of this. Has evolution occured?
No, the change did not occur over time.
Which of these mechanisms cause random evolutionary changes? A) Mutation B) Genetic drift C) Natural selection D) A and B E) All three (A, B & C)
D) A and B
A group of cats are the main species on an island with many different niches. Over time, they develop different features and become entirely different species even though they all came from the same original group of cats. What is this called and why did it likely occur?
Adaptive radiation likely occurred because the cats were occupying different niches for a long period of time.
What directions do ions flow during an action potential?
Down the axon, towards the synapse. Na+ flows into the cell, K+ flows out of the cell.
David develops a disease that breaks down the myelin sheath, what will be the effect on neuron signaling?
Signaling will slow down or stop.
What does the Na+K+ pump require to function?
ATP, which is an energy source
How will gene flow affect the amount of variation between population?
Decreases variation between populations
A population of blue birds is shrinking as the coyote population grows. Local efforts to preserve the population have been unsuccessful and the birds will likely go extinct. A few birds in the same generation are born with darker feathers making them harder to see. Has evolution occurred and why or why not?
No, evolution does not occur to an individual, only a population over time.
Abigail creates a new medication and after testing realizes that it is an acetylcholine mimic, what led her to this conclusion?
Seizures due to increased neurotransmitter at the synapse which led to greater action potentials.
A new spider is discovered whose venom disables ATP use in pumps in neurons, what effect would this have?
The sodium potassium pump would not work, and the ion gradients would not be present which would lead to paralysis.
A drug blocks the neurotransmitter acetylcholine from leaving vesicles. What is likely to occur?
Paralysis since the signal can not be passed to other neurons.
75% of a ladybug population dies during a thunderstorm. This eventually leads to all ladybugs in the population only having one dot on their shell. What term can we use to describe what happened to the population.
Bottleneck effect
A species of bird develops bright pink feathers and creates a dance to attract a mate. What type of sexual selection is this?
Inter-sexual selection
I discover a snake venom that disrupts repolarization of the neuron. List one of the two possible pumps effected and what happens to them.
Na+ pumps cannot close or K+ pumps cannot open.
You discover an alien species that does not use facilitated diffusion. What type of diffusion must they use and what does it require the alien to do?
Active transport requires ATP so the alien would need to create more ATP. Passive transport doesn't require anything.
An axon is at the repolarizing stage of an action potential. What ion is moving and what channels are open/active?
K+ is moving out of the cell, K+ channel is open. K+ leak channel and Na+ K+ pump are always open/active.