Answer:
The correct answer is b. All round seeds
Explanation:
If an RR plant is crossed with an rr plant than all the phenotype will produce round seed and the frequency of the Round seed plant to wrinkled seed plant would be 4:0.
                        R     R
                   r   Rr    Rr
                   r   Rr    Rr
So all the phenotypes will be heterozygous dominant for the round seed which means that all phenotypes will have a single dominant allele for round seed which is enough to express round seeds in the phenotypes.
 
        
             
        
        
        
Answer:
The correct answer is option B, that is, an endoskeleton evolved to enclose the dorsal nerve cord, which develops from the notochord.
Explanation:
It has been discovered that the ancestors of the modern-day fish were vertebrate chordates. The vertebrate chordates are considered to have evolved from the invertebrate chordates that are identical to the present day tunicates. It has been found that in vertebrates the endoskeleton has evolved to encompass the dorsal nerve cord that has been developed from the notochord (a characteristic of invertebrates).
 
        
             
        
        
        
Roots have tint root hairs that maximize the plants ability to absorb water