Biology: The Essentials
Biology: The Essentials
3rd Edition
ISBN: 9781260140705
Author: Marielle Hoefnagels
Publisher: Mcgraw-hill Higher Education (us)
bartleby

Concept explainers

bartleby

Videos

Textbook Question
Book Icon
Chapter 8, Problem 1MCQ

A DNA is placed in a test tube containing fluorescently tagged nucleotides. DNA replication is induced. After replication.

a. only one DNA molecule would have two fluorescent strands.
b. both strands of each DNA molecule would be half-fluorescent.
c. each DNA molecule would have one fluorescent strand.
d. both DNA molecules would be completely fluorescent.
Expert Solution & Answer
Check Mark
Summary Introduction

Introduction:

DNA is a double-stranded nucleic acid that is responsible for the genetic inheritance. Each strand of DNA is a double helix composed of two antiparallel strands of nucleotides. The complementary nucleotides form hydrogen bonds with each other and hold DNA double helix together.

Answer to Problem 1MCQ

Correct answer:

A DNA is placed in a test tube containing fluorescently tagged nucleotides. DNA replication is induced. After replication, each DNA molecule will have one fluorescent strand. Hence, the correct answer is option c.

Explanation of Solution

Reason for correct answer:

Option c. is given as “each DNA molecule would have one fluorescent strand.”

DNA is the genetic molecule and exhibits a double helix structure. According to Watson and Crick, DNA replication is semi-conservative, which suggests that during replication, one strand of DNA will be original and another will be a new strand. In the presence of fluorescent nucleotides after DNA replication, only the new strand will be fluorescent. Hence, option c. is correct.

Reason for incorrect answer:

Option a. is given as, “only one DNA molecule would have two fluorescent strands.”

During DNA replication one of the DNA strands acts as a template and a new strand is formed over it. Therefore, one DNA molecule will always be nonfluorescent if only one replication cycle happens. Hence, option a. is incorrect.

Option b. is given as, “both strands of each DNA molecule would be half-fluorescent.”

During replication, the new strand is formed based on the original strand. Hence one full strand acting as a template will be nonfluorescent, and the new strands will be fluorescent. Hence, option b. is incorrect.

Option d. is given as, “both DNA molecules would be completely fluorescent.”

Both DNA molecules will be completely fluorescent if multiple replication cycles happen. Still the original DNA strands will be nonfluorescent and will have new fluorescent strands. Hence, option d. is incorrect.

Hence, the options a., b., and d. are incorrect.

Conclusion

DNA replication is semiconservative, which means that during replication the original DNA strand will act as a template and new strand is formed over it. Thus, the correct option is c.

Want to see more full solutions like this?

Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
None
Question #3: In the KeyGene paper, the authors state that it would be useful if pollen from an apomict would transmit apomixis-inducing genes to the female in the cross (assuming the pollen is viable). Assuming there was just one gene conferring gametophytic obligate apomixis, and that the two parents are inbreds, what would be the consequences of such a cross if: a) The apomixis was a dominant trait? Indicate the genotypes and phenotypes (apomict or non- apomict) of the parents, F1 and F2 generations. Remember to include the expected genotypic and phenotypic ratios (or percentages) in the F1 and F2 generations, and to position the female first (left side) in the parental cross. b) The apomixis was a recessive trait? Indicate the genotypes and phenotypes (apomict or non- apomict) of the parents, F1 and F2 generations. Remember to include the expected genotypic and phenotypic ratios (or percentages) in the F1 and F2 generations, and to position the female first (left side) in the…
Question #5: Assume that two genes are identified that confer gametophytic facultative apomixis in soybean. The genes show independent assortment. Recessive alleles at both loci are required for the facultative apomixis. Facultative apomixis is triggered when the temperature at pollination is above 20 degrees C. At temperatures below 20 degrees C, all reproduction is sexual, independent of genotype. A facultative apomict male, capable of producing viable pollen, was crossed with a sexually reproducing female. Assuming the parents are completely inbred, what are the predicted phenotypic ratios (apomict: non-apomict) for the F1, F2, and DH (F1-derived) generations at each of the following temperatures*: a) 15°C? b) 25°C? *for full credit, show crosses and genotypes where appropriate. Remember to position the female first (left side) in the cross. Type your answer here:
Knowledge Booster
Background pattern image
Biology
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
SEE MORE QUESTIONS
Recommended textbooks for you
Text book image
Essentials of Pharmacology for Health Professions
Nursing
ISBN:9781305441620
Author:WOODROW
Publisher:Cengage
Text book image
BIOLOGY:CONCEPTS+APPL.(LOOSELEAF)
Biology
ISBN:9781305967359
Author:STARR
Publisher:CENGAGE L
Text book image
Human Heredity: Principles and Issues (MindTap Co...
Biology
ISBN:9781305251052
Author:Michael Cummings
Publisher:Cengage Learning
Text book image
Concepts of Biology
Biology
ISBN:9781938168116
Author:Samantha Fowler, Rebecca Roush, James Wise
Publisher:OpenStax College
Text book image
Human Biology (MindTap Course List)
Biology
ISBN:9781305112100
Author:Cecie Starr, Beverly McMillan
Publisher:Cengage Learning
Text book image
Biology Today and Tomorrow without Physiology (Mi...
Biology
ISBN:9781305117396
Author:Cecie Starr, Christine Evers, Lisa Starr
Publisher:Cengage Learning
DNA vs RNA (Updated); Author: Amoeba Sisters;https://www.youtube.com/watch?v=JQByjprj_mA;License: Standard youtube license