GENETICS(LL)-W/CONNECT >CUSTOM<
6th Edition
ISBN: 9781260571561
Author: HARTWELL
Publisher: MCG CUSTOM
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
thumb_up100%
Chapter 6, Problem 10P
When a double-stranded DNA molecule is exposed to high temperature, the two strands separate, and the molecule loses its helical form. We say the DNA has been denatured. (Denaturation also occurs when DNA is exposed to acid or alkaline solutions.)
a. | Regions of the DNA that contain many A–T base pairs are the first to become denatured as the temperature of a DNA solution is raised. Thinking about the chemical structure of the DNA molecule, why do you think the A–T-rich regions denature first? |
b. | If the temperature is lowered, the original DNA strands can reanneal, or renature. In addition to the full double-stranded molecules, some molecules of the type shown here are seen when the molecules are examined under the electron microscope. How can you explain these structures? |
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
In a melting profile for DNA, the absorbance at 260 nm increases as result of the disruption of the DNA structure. What is the fundamental physical basis for the absorbance increase?
a. the effective concentration of DNA changes
b. the absorbance of DNA is highly sensitive to temperature
c. native DNA absorbs light more strongly than denatured DNA because the bases are stacked
d. denatured DNA absorbs light more strongly than native DNA because the bases have become unstacked
DNA solution is viscous because of the nature of chemical substance that can intercalate into the DNA helix. An example of such substance is acridine orange. experiments revealed that acridine orange causes an increase in the viscosity of DNA solution.how would you account for this effect?
In a paragraph or two, summarize the structural organization of DNA. In your answer, be certain that you identify the chemical components of the molecule, and the arrangement of the molecule (the spatial properties). [You do not need to consider levels of packing of DNA into a cell.]
Chapter 6 Solutions
GENETICS(LL)-W/CONNECT >CUSTOM<
Ch. 6 - Griffith, in his 1928 experiments, demonstrated...Ch. 6 - Griffith, in his 1928 experiments, demonstrated...Ch. 6 - During bacterial transformation, DNA that enters a...Ch. 6 - Nitrogen and carbon are more abundant in proteins...Ch. 6 - If 30 of the bases in human DNA are A, a what...Ch. 6 - Which of the following statements are true about...Ch. 6 - Imagine you have three test tubes containing...Ch. 6 - What information about the structure of DNA was...Ch. 6 - A portion of one DNA strand of the human gene...Ch. 6 - When a double-stranded DNA molecule is exposed to...
Ch. 6 - A particular virus with DNA as its genetic...Ch. 6 - The underlying structure of DNA is very simple,...Ch. 6 - Prob. 13PCh. 6 - Bacterial transformation and bacteriophage...Ch. 6 - The CAP protein is shown bound to DNA in Fig....Ch. 6 - In Meselson and Stahls density shift experiments...Ch. 6 - When Meselson and Stahl grew E. coli in 15N medium...Ch. 6 - If you expose human tissue culture cells for...Ch. 6 - Draw a replication bubble with both replication...Ch. 6 - a. Do any strands of nucleic acid exist in nature...Ch. 6 - As Fig. 6.21 shows, DNA polymerase cleaves the...Ch. 6 - The bases of one of the strands of DNA in a region...Ch. 6 - Replicating structures in DNA can be observed in...Ch. 6 - Indicate the role of each of the following in DNA...Ch. 6 - Draw a diagram of replication that is occurring at...Ch. 6 - Figure 6.18 depicts Watson and Cricks initial...Ch. 6 - Researchers have discovered that during...Ch. 6 - A DNA synthesizer is a machine that uses automated...Ch. 6 - Bacterial cells were coinfected with two types of...Ch. 6 - A yeast strain with a mutant spo11- allele has...Ch. 6 - Imagine that you have done a cross between two...Ch. 6 - The Neurospora octad shown came from a cross...Ch. 6 - From a cross between e f g and e f g strains of...Ch. 6 - In Step 6 of Fig. 6.27, the resolvase enzyme...Ch. 6 - Figure 6.31shows four potential outcomes of...Ch. 6 - Each of the substrates for site-specific...Ch. 6 - Prob. 37PCh. 6 - Suppose that you could inject a wild-type mouse...Ch. 6 - C31 is a type of bacteriophage that infects...Ch. 6 - Cre is a recombinase enzyme encoded by a gene in...Ch. 6 - Like Cre/loxP recombination, site-specific...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- The underlying structure of DNA is very simple, consisting of only four possible building blocks. a. How is it possible for DNA to carry complex genetic information if its structure is so simple?arrow_forwardHow Can Fragments of DNA Be Separated From One Another? Agarose gel electrophoresis is a procedure used to separate DNA fragments based on their sizes. DNA is an acid and has many negative electrical charges due to the negatively charged phosphate-deoxyribose backbone. Scientists have used this fact to modify chromatography to separate pieces of DNA. A solution containing a mixture of DNA fragments of variable sizes is placed into a small well formed in an agarose gel (that has a texture similar to gelatin). An electric current causes the negatively-charged DNA molecules to move towards the positive electrode. Imagine the gel as a strainer with tiny pores that allow small particles to move through it very quickly. The larger the size of the particles, however, the slower they are strained through the gel. After a period of exposure to the electrical current, the DNA fragments will sort themselves out by size. Fragments that are the same size will tend to move together through the gel…arrow_forwardWhen a double-stranded DNA molecule is exposed tohigh temperature, the two strands separate, and themolecule loses its helical form. We say the DNA hasbeen denatured. (Denaturation also occurs whenDNA is exposed to acid or alkaline solutions.)a. Regions of the DNA that contain many A–T basepairs are the first to become denatured as the temperature of a DNA solution is raised. Thinkingabout the chemical structure of the DNA molecule, why do you think the A–T-rich regionsdenature first?b. If the temperature is lowered, the original DNAstrands can reanneal, or renature. In addition to thefull double-stranded molecules, some molecules ofthe type shown here are seen when the moleculesare examined under the electron microscope. Howcan you explain these structures?arrow_forward
- Which of the following statements are correct? explain your answers.A. A DNA strand has a polarity because its two ends contain different bases. B. G-C base pairs are more stable than A-T base pairs.arrow_forwardGiven the following DNA strand: TACAGAGATAACCGAATT A. Write the corresponding strand that would form the other half of the DNA molecule. B. Transcribe the original DNA strand (TACAGAGATAACCGAATT) and write the sequence of bases found in the resulting messenger RNA molecule. C. Translate your messenger RNA molecule and write the sequence of amino acids in the resulting protein (the genetic code is provided below).arrow_forwardDNA structure depends on base pairing of its four nucleotides, A, C, T, and G. Nucleotide A pairs with T, and nucleotide C pairs with G. This forms a four-letter DNA “alphabet." Because DNA codes for amino acids in sets of three nucleotides, there are 4 cubed (4'), or 64, possible combinations, coding for 20 different amino acids. What is the best explanation for why there is no selective advantage for DNA to have five nucleotides (e.g., A, C, T, G, and E) with C pairing with either G or functionally equivalent E? It would be impossible to form the DNA molecule, because it must have an equal number of Cs and Gs. Because G and E have the same role, there would still be four functional letters of the alphabet. Replication would be inaccurate because sometimes C would bond with G and sometimes C would bond with E. There would be a five-letter alphabet with 125 combinations, which is too numerous. It is impossible because there are not five known nucleotides in the cell.arrow_forward
- Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes? Group of answer choices A. All bases would be separated from the deoxyribose sugars B. The purines would be separated from the deoxyribose sugars C. The phosphodiester linkages between deoxyribose sugars would be broken D. The two strands of the double helix would separate E. The pyrimidines would be separated from the deoxyribose sugarsarrow_forwarda. Write the structural formula of GAC, a portion of DNA. Write the complementary strand adjacent to it so that the complementary bases are side by side. Connect the appropriate base pairs. b. Sticking to the convention of writing the nucleotide sequence in the 5'-3' direction, what is the nucleotide sequence of the DNA strand complementary to ATGCACCATGCT?arrow_forwardThe ratio of (A+T) to (G+C) in a particular DNA is 1.0. Is this sufficient data to determine whether the DNA is double-stranded or single-stranded please explain why or why not.arrow_forward
- Assume that the molar percentage of thymine in a double stranded DNA is 20. What are the percentages of the four bases (G, C, T, A)? b. The base content of a sample of DNA is as follows: A=31% G=31% T=19% C=19%. What conclusion can be drawn from this information?arrow_forwardDNA molecules of different sizes are often separated with the use of a technique called electrophoresis . With this technique, DNA molecules are placed in a gel, an electrical current is applied to the gel, and the DNA molecules migrate toward the positive (+) pole of the current. What aspect of its structure causes a DNA molecule to migrate toward the positive pole?arrow_forwardIn a DNA Double helix ,why doesn't an A or T form two hydrogen bonds(out of the three possible) with G or C? Explain in detail.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning
Human Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
Macromolecules | Classes and Functions; Author: 2 Minute Classroom;https://www.youtube.com/watch?v=V5hhrDFo8Vk;License: Standard youtube license