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
likoan [24]
3 years ago
15

In the 1920s, bacteriologist Fred Griffith demonstrated that a heat-killed, infectious pneumococcus produced a substance that co

uld convert a harmless form of the bacterium into a lethal one. Fifteen years later, researchers prepared an extract from the disease-causing S-strain pneumococci and showed that this material could transform the harmless R-strain cells into the infectious S-strain form. This change to the bacteria was both permanent and heritable, suggesting that this "transforming principle" represents the elusive genetic material of the cells. But what kind of molecule was it?The researchers subjected their extract to a variety of tests to determine the chemical identity of the "transforming principle." In one experiment, they treated the material with enzymes that destroy all proteins. This treatment did not affect the ability of the extract to transform harmless bacteria into an infectious form.From this result, the researchers can conclude that:
Biology
1 answer:
Juliette [100K]3 years ago
5 0

Answer:

Some substance in the infectious S strain could change the harmless R strain into the more lethal form.

Explanation:

These first type of experiments where crucial to advance in DNA knowledge.

In one experiment, they treated the material with enzymes that destroy all proteins. This is important because scientist notice that there was something else that was causing the strain to change into a lethal form and was heritable (DNA).  Know a days we know that plasmids are responsible for such transformation.

You might be interested in
How are the processes of natural selection and artificial selection similar? How are they different?
bezimeni [28]
These are similar because they both included desired characteristics. They are different because artificial selection has to do with humans being involved. where natural selection is with out humans being involved and is life or death.
8 0
3 years ago
Your 8-year-old cat ran away, got into a neighbor's cellar, and was stuck there for two months. Luckily, there was enough food a
Vlad1618 [11]

Answer:

The vision remains unaffected.

Explanation:

Rods and cones are two types of photo receptor cells present in the organism. Cone cell helps in the visualization of color whereas rod cells are involved in the light intensity.

The cat was stuck in the neighbor's cellar with enough food and water. The cat was stuck in the basement with pitch-black but this does not affect the vision of cat. Cats are nocturnal animals and has large amount of rod cells that enable them to see at night. Thus, her vision remains unaffected.

5 0
3 years ago
Which scientist determined that the farther a planet is from the sun, the longer it takes to orbit the sun?
Misha Larkins [42]

Answer:

Kepler

<em>Hope</em><em> this</em><em> helps</em><em> </em><em>:</em><em>)</em>

6 0
3 years ago
Read 2 more answers
How is the process of cell division in prokaryotes different from cell divition in eukaryotics
denis-greek [22]
Prokaryotes do not contain membrane, and eukaryotes do contain membrane.
5 0
3 years ago
Why is it important for your heart to keep oxygen-rich blood separate from oxygen-poor blood?
DochEvi [55]

Your heart muscle needs its own supply of blood because, like the rest of your body, it needs oxygen and other nutrients to stay healthy. For this reason, your heart pumps oxygen-rich blood to its own muscle through your coronary arteries.

8 0
3 years ago
Other questions:
  • A major problem with depending on fossil fuels as primary energy sources is that they are
    9·2 answers
  • Three questions a environmental biologist would ask
    15·1 answer
  • 2. Mercury (II) oxide decomposes into mercury and oxygen gas according to the following
    12·1 answer
  • Select all that apply.
    10·2 answers
  • Advantages of written communication​
    6·1 answer
  • What are the basic steps of scientific method? (specifically, I think there are 5 specific steps)
    8·2 answers
  • 1. Blood toxicology screen is clean.
    8·2 answers
  • Two parents have the genotype Gg for a genetic disorder cause by a recessive allele. What is the chance that any of their childr
    15·1 answer
  • Explain various part of a leaf with well diagram​
    7·1 answer
  • What determines the climate of a location?
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!