I believe the correct answer would be <span>variation. The definition of variation in biology means,</span><span> any difference
between cells, individual organisms, or groups of organisms of any
species caused either by genetic differences or by the effect of environmental factors on the expression of the genetic potentials. So i think that organisms can also be classified as variation. Hope this helped. ♥ ☺
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The correct answer should be<span> D) conserving natural resources without harming the environment
Instead of using new resources, you can use the waste from previous production and recycle it for the sake of creating something else, which preserves the resoruces and doesn't harm the environment.</span>
        
             
        
        
        
Explanation:
Create the column headings "Reactants" and "Products". The two row headings should be "Photosynthesis" and "Cellular respiration". 
Before filling in the table, make sure you know what the products and reactants from photosynthesis and cellular respiration are.
Remember reactants are the 'before' on the left, and products are the 'after' on the right.
<u>Photosynthesis</u>:

<u>Cellular Respiration</u>:

See attachment for how the table could look.
 
        
             
        
        
        
The answer should be 2. Skin fossilization is rare due to decomposition and scavengers.
        
             
        
        
        
Answer:
La vejiga natatoria en un pez, se ve afectada por la presión hidrostatica del agua, generando presión y estrechamiento sobre esta, al disminuirse hace más fácil la inmersión, puesto que está vejiga contiene aire que tiene peso menor que el agua y hace flotar con más facilidad al pez, sin embargo cuando el pez sube, la vejiga aumentará su volumen y tendrá que nadar más para mantenerse más abajo en el agua