Why is there a problem in replicating the ends of linear DNA molecules?
What will be an ideal response?
Ans: All known DNA polymerases can only replicate DNA in the 5? to 3? direction. One of the two DNA strands can be replicated to the very end when the polymerase runs off of it, but the other strand (the one with a free 3? end) can only be replicated if the polymerase can begin at the very end. Most polymerases require a primer and cannot begin replication at the 3? end of the template strand.
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a. directional b. stabilizing c. disruptive d. recessive e. fitness
The DNA strands that will be together in the new
DNA molecules are a. A – D and B – C. b. A – B and C – D. c. A – C and B – D. d. A – D – B and A – D – C. e. A – B – C - D.
The part of the stomach designated by the letter “C”
in the above figure is called a. pyloric sphincter. b. esophagus. c. mucosa. d. duodenum. e. none of these.
Which of the following is an example of a mechanical barrier?
A) stomach acid B) mucus C) skin D) lysozyme E) antimicrobial peptides