Are stomata open during the day or night ?

Climate like that in the sahara desert have the fastest rates of weathering

Read this summary of a scientific theory: "cells are the most basic structural and functional units of life. all living organisms are made up of one or more cells. all cells that are alive in the world today came from pre-existing cells." which of the following would require this theory to be modified? -a.) a survey finds that a majority of people believe viruses carry out the basic processes of life. -b.) a prominent scientist says she feels strongly that one day the theory will be challenged by life on other planets. -c.) the dna of unicellular and multi-cellular organisms is shown to have many fundamental similarities. -d.) scientific observations show that microscopic organisms living in the deep ocean are not made up of cells.

Astudent wants to compare the amounts of co2 given off by yeast provided with different amounts of sugar. the student places a balloon over each container to catch the released co2. which observation is a qualitative observation the student can make?