Forests and other green plants uses carbon dioxide in photosynthesis thus lowering its amount in the atmosphere. In assumption, we can claim that in the ice ages, the low level temperatures may have caused the carbon dioxide levels to neutralize over these phenomenons, also to note that there were less oxygen-breathing organisms and higher carbon-dioxide dependent performing photosynthesis. 
        
             
        
        
        
Answer:
complementary DNA (cDNA)
Explanation:
The complementary DNA (cDNA) is a region of DNA that is synthesized from an RNA template by using a reverse transcriptase enzyme. cDNA is usually used to clone genes from eukaryotic organisms in prokaryotes. cDNA cloning is a technique that consists of isolating and amplifying a self-replicating prokaryotic organism that includes in its genome a cDNA of interest. This technique enables the insertion of fragments of eukaryotic DNA (cDNA) into plasmids that subsequently are multiplied by cloning and finally sequenced.
 
        
             
        
        
        
The answer is D. A turtle suns itself on a rock during a cool day
        
                    
             
        
        
        
It will cause vasodilation of blood vessels in the brain.
CO2 is one of the metabolic end products that can alter the
tone of the blood vessels in the brain. High CO2 levels cause vasodilation,
which may cause headache, whereas low CO2 levels cause vasoconstriction, which
may cause lightheadedness. The statements included in the other options are
incorrect effects.