How does a dam negatively affect animals that live downstream? Check all that apply.
It decreases the water level.
It changes the sediment and silt.
It decreases the chance for flooding.
It creates a natural barrier that hides prey.
It stops some animals from being able to travel upstream.

Needed fast 15 points the process of natural selection favors certain characteristics in organisms, while it selects against other characteristics. what would happen if there was zero variation between all of the organisms on earth? a.organisms would evolve to increase variety b.natural selection would operate faster c.less food would be available d.evolution through natural selection would not occur

The creation of the european union has had all of the following effects except

If you were a casual recreational hiker with young children, which of the following trails would be least strenuous for a leisurely family outing? a. merced lake trail b. mirror lake loop trail. c. tenaya lake and tuolumne meadows trail d. el capitan trail