1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Brums [2.3K]
3 years ago
6

In the classic Meselson and Stahl experiment, Coli are first grown in 15N-enriched media (0th generation) and subsequently switc

hed to 14N media. A DNA sample isolated during the first generation of E. Coli grown in 14N media is subjected to a centrifugation step in a dense CsCl gradient. Assuming that replication occurs in a semiconservative fashion, the DNA sample will _______.
Biology
1 answer:
AfilCa [17]3 years ago
8 0

Options are not provided inthe question. Th ecomplete question is as following:

In the classic Meselson and Stahl experiment, Coli are first grown in 15N-enriched media (0th generation) and subsequently switched to 14N media. A DNA sample isolated during the first generation of E. Coli grown in 14N media is subjected to a centrifugation step in a dense CsCl gradient. Assuming that replication occurs in a semiconservative fashion, the DNA sample will _______.

1) run as two bands (of equal intensity), one at the same position as a uniformly 15N-labeled DNA, and one at the same position as a uniformly 14N-labeled DNA.

2) run as one band, at the same position as a uniformly 15N-labeled DNA.

3) run as one band, at the same position as a uniformly 14N-labeled DNA. run as one band, at a position expected for a DNA containing a 14N:15N ratio equal to 7.

4) run as one band, at a position expected for a DNA containing a 14N:15N ratio equal to 1.

Answer:

1)

Explanation:

In 1957, Meselson and Stahl gave an experimental evidence for semi-conservative replication  of DNA, means that each DNA strand act as template for synthesis of new DNA.

For the experiment, they use  E. coli grown in heavy isotope of 15N nitrogen and switch to 14N nitrogen undergoing one, two, or three generations and the DNA samples are collected. The DNA samples are then mix with cesium chloride and separated as light and heavy DNA.

As the replication occurs in a semiconservative fashion, the double DNA sample will run as two bands with intermediate density, having mixtures of 15N and 14N DNA, either of which would have appeared as DNA.

Hence, the correct option is (1).

You might be interested in
Which of the following would require an input of energy? Question 5 options: a)  diffusion b)  filtration c)  osmosis d)  vesicu
Taya2010 [7]

Answer:

Which of the following would require an input of energy? Question 5 options: a)  diffusion b)  filtration c)  osmosis d)  vesicular transport

Explanation:

vesicular transport

4 0
3 years ago
Read 2 more answers
Identify the type of neuronal cell that detects bright light and provides high-resolution color vision.
alina1380 [7]

Answer:

The correct option is b. cones.

Explanation:

Cones and rods are specialized cells, called photoreceptor cells, that are found in the retina and are responsible for our vision.

Cones, allow to the human eye to have a visual acuity (ability of the eye to resolve, transmit sharp images and perceive small details in an object) and provide sensitivity to the color, are more concentrated in the central yellow spot known as the macula.

There are three different types of cones in color reception: "L cones" (sensitive to long wavelength, which is red), "M cones" (sensitive to medium wavelength, which is green) and "S cones" (sensitive to short wavelength, which is blue). Since color perception depends on the activation of these three types of nerve cells, it follows that the visible color can be determined based on three numbers called triestimulus values.

The rods are necessary for the perception of light and darkness and to adapt to night vision, because they are very sensitive to low intensity light. On the contrary, they become completely blind to bright light and, therefore, lack importance with regard to daytime vision or visual acuity.

8 0
3 years ago
Which of the following categories of ecosystem services allows us to make medicine from a rare plant grown in Chile?
AnnyKZ [126]

Answer:

REGULATING,

PROVISIONING,

SUPPORTING.

Explanation:

:)

4 0
3 years ago
What is community ecosystem individual and population from least to greatest?
Natasha_Volkova [10]
Individual , population , community then ecosystem.
5 0
3 years ago
At low temperatures, a particular enzyme catalyzes a reaction, but at a slow rate. At high temperatures, the enzyme is completel
Orlov [11]

At the low temperature, a particular enzyme catalyses a reaction best explains temperature affects the function of this enzyme.  

Explanation:

Enzymes are those catalysts which is generally proteins through some RNA molecules as enzymes too.  The activation energy of reaction of Enzymes lower is required amount of energy which is needed for occurring the reaction.

Temperature, pH and concentration affect the Enzyme activity. The raising of temperature generally speeds up the reaction. Due to high temperature enzyme to lose its shape and stop working.  The part of enzyme where substrate bind is called the active site.  

5 0
3 years ago
Other questions:
  • How are small leaves an adaptation in a desert environment?
    11·1 answer
  • Structures that no longer serve their original function are called _____ structures.
    10·1 answer
  • Which organ filters out urea, water, and salt as blood flows through it?
    14·1 answer
  • 14. Allergies are caused by which of the following?
    10·1 answer
  • Explain two things we can learn from fossils. (3 points)
    8·1 answer
  • What role does the cell membrane play in maintaining homeostasis
    8·1 answer
  • What type of rock forms due to high pressure?
    13·2 answers
  • Please help me with this​
    14·2 answers
  • Please number these from smallest to largest.
    10·2 answers
  • Based on the structure of proteins, how would you explain why Beau’s coat hair changed from straight to curly? Be your explanati
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!