Answer: A prokaryotic cell is a simple, single-celled (unicellular) organism that lacks a nucleus, or any other membrane-bound organelle. We will shortly come to see that this is significantly different in eukaryotes. Prokaryotic DNA is found in the central part of the cell: a darkened region called the nucleoid Unlike Archaea and eukaryotes, bacteria have a cell wall made of peptidoglycan, comprised of sugars and amino acids, and many have a polysaccharide capsule (Figure 1).
Explanation:
 
        
             
        
        
        
Attached is the image of the concerned ECG reading.
In reading the ECG, first you read the heart rate. To read the heart rate, you must count for the number of small boxes in between QRS complexes, specifically R-R intervals. These number of small boxes will then be used to divide 1500. In this example, there are 20 small boxes between R-R intervals. 1500 divided by 20 is 75, so the heart rate of this ECG reading is 75 beats per minute. 
<em>Another way, albeit less accurate, is to count the big squares between R-R intervals and instead of dividing it by 1500, you divide it by 300.</em>
 
        
        
        
Acids correspond to volatile molecules that release positive hydrogen ions. These ions have a profound effect on the other molecules in foods. Also, they can affect the cells in your body, fortunately, our taste buds help us regulate the number of free hydrogen ions we eat by making us perceive acids as sour tasting.
        
             
        
        
        
Answer:
D.-
Explanation:
A control group is needed to carry out the experiment, that control group is the one that is not injected with anything.  Ethanol and pesticide need to be injected into separated groups to document whether it is one or the other that is harmful 
 
        
             
        
        
        
A. Natural Selection.  This is because the weeds that are not resistant to it die out before they can reproduce, but the resistant ones grow to maturity and then reproduce, passing down the resistance gene.  Over time, the resistance gene would become a normal thing in weeds, while the non-resistant gene would not exist anyone, since the gene could not be passed on.