Answer:
it's because of a pigment called cholorophyll present in leaves..
 
        
                    
             
        
        
        
Hello there!
38. A) Wavelength
39. True
40. B) Alfred Wegener
41. False
42. False
43. ?
44. B) Conduction
45. C) Convection
Hope this helps!
        
                    
             
        
        
        
The bulk of the heart rests on the side of the body. On the left side
 
        
             
        
        
        
The plants that were allowed to self pollinate were the F1 plants. 
The plants that are true breeding are P generation plants. 
The plants where there were 3times as many tall plants as short plants are in F2 generation. 
<h3><u>Explanation:</u></h3>
This question is based on the Mendel’s Experiment. Sir Gregor Johann Mendel was the father of genetics who experimented on garden pea plants <em>Pisum</em> <em>sativum</em> to see whether the characters got mixed or not and to know the real cause behind different traits of same character in plants. 
He took the pure homozygous tall and short plants separately which he called as parental generation or P generation. These plants were homozygous, hence pure breeding. 
As these plants were crossed between themselves, then the F1 generation showed all tall plants. This is because of the heterozygous plants which showed character of dominant trait. These plants were allowed to self pollinate. 
As a result of self pollination of the F1 plants, the F2 plants were 75% tall in number whereas the other 25% short, which gave the phenotypic ratio of 3:1.
 
        
                    
             
        
        
        
<em>sieve tube elements are the cells of phloem which allow transportation of photosynthates through phloem...
<u>
how sieve tube elements form sieve tubes:
</u>sieve tube elements are connected end to end and form a long chain which is called sieve tube,,,,
sieve tube elements are connected with the help of a side chain with the help of peptide bond...also one element has tapering end which easily overlaps with other end of next element to form sieve tube,,,,</em>