Which are producers within a spruce-fir forest ecosystem? a. mushrooms b. pine martins c. snowshoe hares d. limber pine trees

Which of these serves as a reference for comparison during a scientific investigation? a)outcome variable (dependent variable) b) test variable (independent variable) c)control group d)hypothesis

The distribution of related animals and plants across the world

Which best describes a gene? a. a sister chromatid b. a chromosome c. a tetrad d. a piece of a chromosome