Answer AND Explanation:
Gnetophytes are gymnosperms
, they are woody  and the embryo has two cotyledons
. Cycads are woody plants that produce seeds found in Subtropical and warm temperate regions and also they produce motile sperm cells.
 
        
             
        
        
        
Answer:
I believe the answer to this question is b observable physical evidence.
Explanation:
The reason for this is because scientists make predictions and use evidence to back up their hypothesis. If the evidence doesn't support their claim, they make up a new one, until they have gathered enough evidence to support their claim. This can be done through past knowledge, like failures and successes and lab experiments, so it is not only each of them, so the answer cannot be c or d. Out of the two options, a and b, I just thought about it and picked b as the reasonable answer. Please give me feedback on the answer, if it is right or not. Thanks! Hope I helped!
 
        
             
        
        
        
Answer:
Isotonic
denoting or relating to a solution having the same osmotic pressure as some other solution, especially one in a cell or a body fluid.
Hypertonic 
having a higher osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid
Hypotonic
having a lower osmotic pressure than a particular fluid, typically a body fluid or intracellular fluid.
Explanation:
 
        
             
        
        
        
The SECOND graph represents selection that may lead to reduced variation. It is an example of stabilizing selection.
<h3>What is Stabilizing selection?  </h3>
Stabilizing selection is a type of natural selection that leads to a  decrease in the genetic variation of the population.
In Stabilizing selection, natural selection tends to favor an average phenotype and then can remove (select) extreme variations. 
Stabilizing selection generates a modified bell curve graph in which the central portion is narrower and it is taller than the normal distribution bell shape. 
Learn more about Stabilizing selection here:
brainly.com/question/8563440