In the classic Meselson and Stahl experiment, E. coli are first grown in 15N-enriched media (0th generation) and, subsequently, switched to 14N-enriched 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:____________
a) 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.
b) run as one band, at the same position as a uniformly 15N-labeled DNA.
c) run as one band, at the same position as a uniformly 14N-labeled DNA.
d) run as one band, at a position expected for a DNA containing a 14N:15N ratio equal to 7.
e) run as one band, at a position expected for a DNA containing a 14N:15N ratio equal to 1.

Answers

Answer 1

Answer:

The correct answer is - option e.)

Explanation:

The experiment that was performed by Meselson and Stahl was created to prove that DNA replication is a semiconservative process.

When Bacteria grow on 15N media they incorporate the isotype of nitrogen and after few generations, the culture moved to 14N media where it incorporates as they replicate in semi-conservative mode and one DNA strand comes from the Parent DNA.

The right option for question one is Option (e) Run as one band, at a position expected for DNA containing a 14N:15N ratio equal to 1.


Related Questions

HELp! Please?????


Which organs are part of the musculoskeletal system? Select three choices. bones hair muscles skin tendons nails

Answers

Answer:

The bones, muscles and tendons

Ecto parasite poultry are controlled by​

Answers

Answer:

“Ectoparasites,” or parasites that feed on the outside of the body, may cause considerable loss to a poultry operation, particularly by lowered egg production. ... Infestations of external parasites on poultry can be economically controlled with good sanitation and with proper use of insecticides.

Most Sequoias are found in which state__________________?

Answers

Answer:

Northern California

Explanation:

why is transportation of molecules into and out of a cell important for cell function

Answers

The purpose of the transport proteins is to protect the cell's internal environment and to keep its balance of salts, nutrients, and proteins within a range that keeps the cell and the organism alive. There are four main ways that molecules can pass through a phospholipid membrane.

What would most likely happen to a person who is not getting enough essential amino acids in his or her diet?
A.The body would synthesize the amino acids.
B.Muscle growth and repair would be limited.
C.Stored protein would break down.
D.The formation of proteins would increase.

Answers

Answer:

The correct answer I believe would be C

Explanation:

B. There would be reduced muscle growth and healing. The body cannot synthesise essential amino acids on its own; therefore, they must be consumed through diet.

What is the reason for body not using protein ?

The body cannot use the protein it consumes for muscle growth and repair when a person's diet is deficient in critical amino acids. In addition to increasing the risk of injury, this can result in a loss of muscle mass and strength.

Additionally, in an effort to obtain the critical amino acids it requires, the body can start to break down protein that has been stored, which would result in a further loss of muscle mass and strength.

Alternatively, the body can create non-essential amino acids, thus whenProtein synthesis won't necessarily increase if a person isn't obtaining enough necessary amino acids. The body will instead concentrate on converting protein that has been stored into the vital amino acids it requires.

Therefore, a reduction in muscle growth and repair is the most likely consequence of consuming insufficient amounts of necessary amino acids.

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Match each description with the appropriate term listed
Fungi
Viruses
Bacteria
Protozoans

Answers

Explanation:

they all are microorganisms and are different kind of category....

The process of _________________ produces the gametes - sperm and egg.

Answers

Answer:

meiosis

Explanation:

Answer:  Meiosis

Explanation:

Which of the following statements is true?

The dissolving power of water is very important for the transport of nutrients in blood.
The solid form of water is more dense than the liquid form, which is why ice floats.
Cohesion helps plants transport water from their roots to their leaves.
Surface tension is a measure of how much water molecules are attracted to other materials.

Answers

Answer:

The dissolving power of water is very important for the transport of nutrients in blood.

Explanation:

Water is known as the "universal solvent" because it can dissolve more substances than any other liquid. The dissolving power of water means that it can effectively transport nutrients, chemicals, and minerals. Plants rely on water to carry dissolved nutrients from the soil. Animals also benefit from water as a solvent.

Answer:

A. The dissolving power of water is very important for the transport of nutrients in blood.

Explanation:

Hope it helped!

Renters: A. Have more flexibility for when they can move out B. Are not responsible for damages such as leaking ceilings C. Are not required to pay for housing insurance D. All of the above I WILL MAK YOU BRAINELEST

Answers

Answer:

answer is D i think

Answer:

D !

Explanation:

THATS THE ANSWER FORSURE

Why is meiosis important to sexually reproducing organisms?

Answers

Answer:

Meiosis is important for organisms that reproduce sexually because it is the cell division that serves to obtain gametes or sex cells.

Explanation:

Meiosis is a reductive cell division, involved in the gametogenesis process, where from a diploid cell haploid cells called gametes are obtained.

The gametes, also called sex cells, are responsible for containing the genetic information that each individual will transfer to their offspring.

In sexual reproduction, the importance of gametes is that the paternal and maternal gametes unite in a process called fertilization, to give rise to a diploid cell called a zygote.

PLZZZZZ hELP
When light passes from one medium to another, it bends. This phenomenon is
known as what?
reflection
refraction
subtraction
distraction

Answers

answer is refraction .

If we are all related, why don’t we look the same?
Someone please help.

Answers

Answer:

because we all have different genes and DNA!

If mice from the F1 generation are crossed, their offspring are the .

Answers

Answer: The answer is the F2 Generation!

Explanation:

I just got it roght boi!

Answer:

it would be F2 gen

Explanation:

got it correct

Which of the following is not associated with the light-driven reactions?
Biology

Answers

Answer:

soil,air and water

Explanation:

give nutrients to plants and release oxygen

why do microorganisms interact

Answers

Answer:

it is frequently related to pathogenic or beneficial effect to host

Explanation:

it is an important role

Which of the following elements makes up the tissues and organs of animals? Carbon Hydrogen Nitrogen Oxygen

Answers

Answer:Carbon

Explanation:

Carbon is one of the most important elements for the structure of living things. It is responsible for 19% of the body composition of animals, behind only oxygen, which contributes 61%. The head is one of the main elements that make up the tissues and organs of animals.

Answer:

carbon

Explanation:

i took the test

A scientist repeats Mendel嚙編 experiment. The scientist got the following results: A table shows that 669 plants have purple flowers and 221 plants have white flowers. What is the ratio of purple flowers to white flowers? :1

Answers

Answer:

the answer is 3.03

Explanation:

when you do 669 / 221 you get 3.03

hope this helped  :)

CAN ANYONE HELP ME WITH THE QUESTION ABOVE

Answers

Answer:

D im pretty sure

Explanation:

When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur? A. The cell will burst. B. Plasmolysis will shrink the interior. C. The cell will become flaccid. D. The cell membrane will lyse. E. The cell will become turgid.

Answers

Answer:

The answer is "Option E".

Explanation:

The turgid relates to cells or tissues swelling from its transport of moisture. Some types of cells would become turgid because of moisture absorption in several distinct species. Its vacuole is swelling or pressure created mostly on cell walls, that's why whenever a cell membrane is submerged inside an extremely isotonic solution including a cell of a peony stem, the cell becomes turgid.  

An hypotonic solution is a solution when compared to others have a relatively low solute concentration.

So when a cell is placed in a hypotonic solution, the cell will become turgid. (option E).

When this cell is placed in a hypotonic solution, there is the flow of water across the solution and its surrounding environment. In a hypotonic solution, the solute concentration is lower than inside the cell. This flow continues until there is a net flow and equilibrium is achieved. The cell in this process gains volume and becomes entirely turgid swelling up.

Learn more about turgidity: https://brainly.com/question/18740086

Which statement explains why many scientists believe that carbon dioxide has likely contributed more to global warming than other greenhouse gases?

Carbon dioxide is emitted from fertilizers used in farming.
Other greenhouse gases trap more heat than carbon dioxide.
Carbon dioxide has increased as a result of increased human activities.
Carbon dioxide is emitted from commercial refrigeration.

Answers

Answer:

C. Carbon dioxide has increased as a result of increased human activities.

I got it correct on my Quiz!!

GIVE THE OTHER PERSON WHO ANSWER THIS QUESTION CREDIT!!!

CO₂ is a gas that composes the atmosphere, but its increase contributes to the greenhouse effect. C)CO₂ has increased as a result of increased human activities.

What is CO₂, and how does it affect the greenhouse effect?

Carbon dioxide (CO₂) is a gas that, among other gases, composes the atmosphere, mainly the troposphere, which is closest to the Earth.

The balance of this gas in nature is very complex and involves interactions between the atmosphere, the plants, and the oceans.

CO₂ is essential for plants to photosynthesize. Photosynthesis transforms CO₂ into organic compounds and releases oxygen as final products together with carbohydrates.

This gas is not nocive at concentrations between 300 and 500 ppm. However, the current increase in CO₂ is a responsible component of the greenhouse effect involved in global warming and climate change. The rise in CO₂ is possibly the best documented.

The atmospheric increase of CO₂ follows a natural fluctuation trend that has been happening throughout the whole of Earth's history.

It has been proven that the current rise in CO₂ concentration overlaps the expected variation and that the reached levels at the moment exceed the highest past registered levels. This substantial increase must be related to human activities, such as forest destruction, industry, and fossil fuel uses, among many others.

The correct option is C. Carbon dioxide has increased as a result of increased human activities.

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Which causes genetic recombination?
Question 21 options:
alleles
crossing over
genes
hybrid crosses

Answers

Answer:

Recombination occurs when two molecules of DNA exchange pieces of their genetic material with each other. One of the most notable examples of recombination takes place during meiosis (specifically, during prophase I), when homologous chromosomes line up in pairs and swap segments of DNA.


During prophase, chromatin condenses into ____

Answers

During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes. Chromosomes are made of a single piece of DNA that is highly organized.

The organelle that is a major producer of ATP and is found in both heterotrophs and autotrophs is the

Answers

Mitochondria is the answer to your questions

green lawns use too much water what is the consciousnes

Answers

Answer:
weed yards

Step by step explanation

Organisms differ in how they obtain energy, and they are classified as autotrophs or heterotrophs based on how they obtain their energy in an ecosystem. ... organisms that contain chlorophyll absorb energy during photosynthesis and use it to convert the inorganic substance carbon dioxide and water to organic molecules. Why?

Answers

Answer:

Organisms differ in how they obtain energy, and they are classified as autotrophs or heterotrophs based on how they obtain their energy in an ecosystem. ... organisms that contain chlorophyll absorb energy during photosynthesis and use it to convert the inorganic substance carbon dioxide and water to organic molecules. Why?

Explanation:

What monomer is needed to speed up chemical
reactions?

Answers

Answer:

Enzymes

Explanation:

Proteins are polymers made up of ammo acids. Enzymes are a category of proteins. They are catalysts. They speed up the rate of a chemical reaction.

Plants use photosynthesis to turn sunlight, air, water, and nutrients into food energy

is it true or false ​

Answers

It is true because through Photosynthesis plants catches solar energy

multiple choice
this major site of protein synthesis has ribosomes attached to it and protects proteins within its folds from being exposed to the cell’s internal environment.

a. rough endoplasmic reticulum
b. smooth endoplasmic reticulum
c. golgi apparatus

Answers

Answer:

Its a

Rough endoplasmic rectulum

Or RER.

Based on the information presented what can the students conclude about what caused the disturbance in this forest community?
secondary succession after a fire
O primary succession after a mudslide
O primary succession after a volcanic eruption
O Secondary succession after a glacier recedes

Answers

Answer: A. secondary succession after a fire.

Explanation: The graph shows a disturbance and then the ecosystem rebuilding itself which would mean it goes through secondary succession.

Which term means "surgical
creation of a new opening to the
outside from the windpipe"?
A laryngectomy
B. tracheotomy
D. tracheostomy

Answers

Answer: D. Tracheostomy

Explanation: hope this helps
It’s D because that is the only one that makes completely since
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