D. Plants have adapted to deal with the sun in many different ways, and this is one. The stomata are regulated by guard cells, which are activated by different things depending on the species of plant, and guard cells are supposed to keep the stomata from staying open all the time and losing too much water to evaporation. So, the solution is to have the stomata on the bottom of the leaf to prevent direct sunlight contact (and therefore more evaporation), and guard cells to protect the stomata. 
        
             
        
        
        
Material through which water flows is permeable. This material can be either natural or artificial. Naturally permeable material can be clean sand and gravel for example, or a sandstone and in the latter case the sandstone can have both porosity which is not synonymous with permeability as the pores must be connected to be permeable. An impermeable membrane could be used to line ditches for example to prevent leakage near mines. 
        
             
        
        
        
Answer:
Explanation:
Cell specialization is also called cell differentiation. Through this process, specialized cells form from the unspecialized cells. Then many cells are formed and determined to form specialized functions.
The stem cells are the unspecialized cells which form a different kind of specialized cells.  
The muscle cells, nerve cells, sperm cells, red blood cells are specialized cells perform different specialized functions. All these cells arise from stem cells. The nerve cells receive impulse, muscle cells can contract, etc.
There are certain inductive signaling genes that send the signal to the differentiated cells. These signaling molecules are called ligands. These ligands move to another cell to produce specialized cells. In other words, there are some transcription factors and genes responsible for such cell differentiation and the formation of specialized cells.
Another example is zygote, which is an unspecialized cell. This is also a totipotent cell that has the potentiality to reproduce different cells. 
 
        
             
        
        
        
Biodiversity is variety of life. Bio means life and diversity means change, different forms of life. The world constitute different species of plants and animals. Have a nice day!
 
        
             
        
        
        
Answer:
If it´s not A then choose C
Explanation
If they were land animal and could not swim then the only logical reasoning would be that the two pieces of land drifted apart from each other and the fossils were in between them and that´s why they ended up in the ocean.