Some applications in biology, such as polymerase chain reaction (PCR), require melting the DNA double helix into single strands of DNA. This can be accomplished by heating the DNA. As DNA is heated, why does the double helix structure denature into single strands of DNA but not into individual nucleotides? In other words, why do the single strands remain intact even though the double helix does not?
A. The double helix structure is important for DNA replication, while the single strands carry the information.
B. The single strands are wrapped around histones, which protects them from denaturing.
C. The double helix is held together with phosphodiester bonds, while the single strands are linked by hydrogen bonds.
D. The double helix is held together with hydrogen bonds, while the single strands are linked by phosphodiester bonds.
Answer: D. The double helix is held together with hydrogen bonds, while the single strands are linked by phosphodiester bonds.
You might also like to view...
The process of ________ occurs when molecules move down a concentration gradient due to random molecular motion
Fill in the blank(s) with the appropriate word(s).
A novel protist was discovered on a rock sample in a hot spring. Your task is to determine the lengths of DNA associated with its nucleosomes so that a colleague can then determine the nature of the proteins that comprise the nucleosome
How would you go about determining the lengths of these DNA fragments? What will be an ideal response?
DNA ligase functions to
A. catalyze the formation of hydrogen bonds between adjacent 5'?P and 3'?OH termini. B. relax supercoiling of DNA. C. add methyl groups to DNA. D. facilitate base pairing between single?stranded molecules of DNA. E. catalyze the formation of covalent bonds between adjacent 5'?P and 3'?OH termini.
The following events elicit an antibody response. What is the third step?
A) Antigen-digest goes to surface of APC. B) APC phagocytizes antigen. C) B cell is activated. D) TH cell recognizes antigen-digest and MHC II. E) TH cell produces cytokines.