What is the major cause of changes in gene expression?

Which statement is true about the cell theory? a) it is well-supported by evidence. b) it is unchangeable and permanent.

The carbon cycle is best defined as a process in which a. carbon changes from inorganic forms to organic forms and back b. carbon is changed into other elements such as oxygen or nitrogen c. carbon is continually created from the sun’s energy by plants d. carbon is consumed and regenerated from other elements such as oxygen and nitrogen

Which best describes carbon dioxide’s path out of the body