Answer:
1. It was a control variable
2. Type of insulation
3. Temperature
4. Plastic lids <em>or </em>Water <em>or </em>Half Full <em>or </em>Direct Sunlight
Secondary succession happens more often because it occurs after some kind of distribution that still leaves the soil intact (mudslide,bulldozing,shoveling,or scraping off an area)
The right option is; extreme traits
Disruptive selection events select for extreme traits.
Disruptive selection is a type of natural selection in which organisms with extreme traits are favored (such as in reproduction) over organisms with intermediate traits. This type of selection results in increased traits differences with increase in frequency of the alleles for the extreme traits. Disruptive selection can lead to the digression in a species line.
D : the number of generations in one population