Answer:
A should be your answer. I know this was yesterday, but if this was it, let me know
Explanation:
 
        
             
        
        
        
Hi there! This question is a bit confusing. 
 Primary cells more of have one "star" quality; they are not rechargable. Think of them like a battery in a TV remote! You replace them, they can't recharge. 
Secandary cells, though, can be electrically recharged! Like your phone battery, plug it in and a few hours later, full battery.
 Your answer would be "Secondary cells are rechargable" 
Have a great rest of your day!
 
        
             
        
        
        
Answer:
Calcium is a chemical element with the symbol Ca and atomic number 20.
Explanation:
 
        
                    
             
        
        
        
Random changes in allele frequency in a population are usually called genetic drift. The reason why this is the answer is because it is a very specific word which is used to describe exactly that - random changes in allele frequency. 
All the other cases; answers, here aren't correct and don't apply. 
        
             
        
        
        
The question is incomplete as it does not have the options which are:
(a)DNA (b)tRNA (c)rRNA (d)mRNA
Answer:
Option-mRNA
Explanation:
The mRNA is synthesized from the DNA and which is also a type of nucleic acid. When the nucleic acid is extracted from the yeasts and then mixed with the resin beads to which the polynucleotide with thymine base oar is attached.
The mRNA will bind to the resin bead as the mRNA after synthesis undergoes modification and attaches poly A tail to the end of the mRNA at 3' end.
This poly-A tail has adenine which easily binds to the thymine and thus mRNA easily attaches to the resin bead.
Thus, mRNA is correct.