The right answer is A.
Plant species are particular in their ability to produce oxygen and carbohydrates through photosynthesis. The plant, just like the animals also needs to breathe so that these cells survive, so it is forced to take some of the oxygen and carbohydrate produced by photosynthesis to operate these cells through cellular respiration.
 
        
             
        
        
        
The folds of the mitochondria
        
             
        
        
        
Answer:
The correct answer is A. Tobacco mosaic virus 
Explanation:
Virus can have DNA and RNA as its genetic material. Tobacco mosaic virus has RNA as its genetic material. Protein is not a genetic material because it is a product coded by genetic material.  
So a hybrid can be made only when the genetic material of two different organisms is mixed not two different biomolecules. Therefore when RNA from the tobacco mosaic virus is mixed with the protein from a DNA virus the result would be a tobacco mosaic virus only. 
 
        
             
        
        
        
What your cells have to help overcome a problem of high activation energy are called enzymes. Enzymes are proteins that lower the activation energy of a reaction. In doing this, enzymes increase the rate of a reaction, helping it to occur faster. However, enzymes are not consumed in a reaction; they simply help it to occur.
Enzymes make things easier for your cells to work properly and help chemical reactions occur. There are hundreds of different kinds of enzymes in your cells, which all participate in different types of reactions. Enzymes can break molecules apart, build or add molecules, and even rearrange them.
In lowering the activation energy of a reaction, enzymes decrease the barrier to starting a reaction. It's important to note, however, that the change in energy remains the same between the start and end of a chemical reaction.