Manipulative experiments alter levels of a predictor variable (or factor), and then measures how one or more variables respond to these alterations. ... Natural experiments-An observational study in which we take advantage of natural variation that is present in the variable of interest.
Answer:
The answer is "The temperature of the water."
Explanation:
Because he is trying figure out if the temperature affects how the crayfish lives
I believe the correct answer is option C. Weathering produces the sediments that ultimately lead to soil formation. Soil formation is the result of a combination of five factors: parent material, climate, topography, biological factors, and time. Hope this answers the question.
The sequence of amino acids in a protein is determined by DNA. In a protein that is present in all species, the amino acid sequence will be different. Once a protein has been chosen, the amino acid sequence of that protein in different species are compared. More similarities, or fewer differences, indicate that two species are closely related. (sorry if im wrong!)
Answer:
Because the vaccine is an antigen from living, weakened or killed microorganisms that activate the immune system and the body produces protective antibodies.
