The correct answer is - the variable.
With the experiment, in the way that Dan had decided to perform it, the fertilizer is the variable, as in one of the parts with strawberries he uses fertilizer, while in the other part he doesn't uses fertilizer.
While this kind of experiment may give Dan some answers, and he might notice differences, still he would have to be more detailed in the experiment to see for sure if the fertilizer is the thing that makes some of the strawberries grow better than the others.
Dan should also put all of the strawberries at places that would receive the same amount of light, experience the same weather conditions, receive the same amount of water, and to be planted in a soil of the same quality. Only like this, after putting the fertilizer, Dan can now if it makes any changes or not.
The right answer is opposite.
In the air, the biomass of primary producers is often much higher than the biomass of consumers, especially in forests where a large part of the biomass is wood. In aquatic environments and especially oceanic, the biomass of primary producers (phytoplankton) is generally lower than that of consumers but this biomass is rapidly renewed.
Answer: freeze-thaw cycles and hot and cold cycles
Explanation:
The poison dart frog suddenly increase if the predator that feeds off the dart frogs goes extinct or migrates to a different area then the dart fronts will have a much larger population.
This means that the resources the dart frogs rely on will start to diminish and their prey will have smaller numbers
A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics.
