A Population of Birch Trees Is Present on the Side

question 16

Multiple Choice

A population of birch trees is present on the side of a mountain and is preyed upon by beetles that burrow into bark. Which tree would be the most fit?

• A) a tree that grows to be the tallest
• B) a tree that has thicker bark
• C) a tree with more active photosynthetic enzymes
• D) a tree that has thick, strong roots

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Definitions:

Above-Threshold

Pertaining to a stimulus strength that is sufficient enough to be detected or to produce a response.

Depolarizing Current

An electrical current that reduces the membrane potential of a neuron, making it more likely to fire an action potential.

Action Potential

is a rapid change in the electrical potential of the membrane of a nerve or muscle cell, allowing for the transmission of signals.

Synaptic Vesicles

Small sacs in a synapse that release neurotransmitters into the synaptic cleft to transmit signals between neurons.