Look at the arrows pointing toward atmospheric CO2. What are the two major sources of atmospheric carbon?

Transmission electron microscope are best for viewing a) microorganisms in pond water b) internal organs of a mouse c)internal structures of a cell d) surface features of a specimen

How many chromosomes does each human cell contain? a. 23 chromosomes b. 26 chromosomes c. 43 chromosomes d. 46 chromosomes

What are the student's observations and inferences before he starts his investigation?