Answer:
Usually, Populations have a genetic variation among individuals, which is important to the population's ability to survive in different situations that have an effect on the natural selection. There are different factors which can increase or decrease the genetic diversity, and influencing natural selection.
These factors include an environmental factor, one of the major factors, which may cause changes in the genetic variation of a population and influence the natural selection. A famous and important example of environmental factors affecting natural selection was during the Industrial Revolution, when many more grey moths made up the moth population. 
This was so that they could blend in with the soot from factories to avoid predators.
 
        
                    
             
        
        
        
According to the U.S. Geological Survey, most of that three percent is inaccessible. Over 68 percent of the fresh water on Earth is found in icecaps and glaciers, and just over 30 percent is found in ground water. Only about 0.3 percent of our fresh water is found in the surface water of lakes, rivers, and swamps. The use for the water in the world is for household drinking water. The ocean stores about 97 percent of the Earth's water; the remaining three percent is stored in glaciers and ice, below the ground, in rivers and lakes. Of the world's total water supply of about 332 million cubic miles of water, about 97 percent is stored in the ocean.
Hope this helps!
 
        
             
        
        
        
Answer:
D. heterotrophic by ingestion, pseudopods
Explanation:
Protists are generally classified  as all eukaryotic organisms that are not plants, animals or fungi. Example is amoeba, paramecium etc.They may be unicellular or multi cellular in nature.Most exist in colonies.
Their mode of nutrition can be photosynthetic or hetrotrophic. Hetrotrophic  protists   can be divided into  phagotrophs and osmotrops/saprotrophs. The phagotrophs  makes use of the cell body to engulf the food materials as  in amoeba ,carry out extracellular digestion before swallowing it.
 Osmotrops absorbed dissolved food from surrounding liquid environments directly. (Some photosynthetic protists can also be heterotrophic.
Amoeboid movement is the mode of locomotion of protists and some  other eukaryotes. It involved the protrusion of cytoplasm, which exert pressure on the cell membrane to form pseudopodia and  the posterioly  evolved  <u>Uropods. </u>
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<u>  </u>
<u>Sol-gel theory has been proposed to expalin this movements, The ectopalsm of amoeba is gelly-like , while the endiplams is less viscpus   and said to be sol. The interchange of the cytoplasmic fluis between the endo-and ecto plasm gives the SOL-GEL propulsion of the protopalms for the amoebic moveemnts .</u>
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<u>The false feet(psuedopodium) drags the amoeba  along in the direction of the flow of the cytoplasm.</u>
Therefore option D is  the right option
 
        
             
        
        
        
Answer:
c. Aa Bb
Explanation:
The parents were pure breeding with genotypes AAbb and aaBB. A cross between AAbb and aaBB would produce AaBb genotypes in F1 progeny. Two F1 strains would be crossed to produce F2 progeny. The F2 progeny would have the genotype ratio= 1:2:1:2:4:2:1:2:1. 
Out of all the obtained genotypes in the F2 generation, the proportion of "AaBb" genotype was 4/16. Therefore, "4" in the given ratio represents the genotype "AaBb".