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
fredd [130]
3 years ago
5

Levene made which contribution to our understanding of DNA structure? a. He determined that the nucleus contains DNA. b. He dete

rmined that DNA contains four nitrogenous bases. c. He determined that DNA consists of nucleotides. d. He determined that the nitrogenous bases of DNA are present in regular ratios.
Biology
1 answer:
Stels [109]3 years ago
8 0

Answer:

The correct answer is  b. He determined that DNA contains four nitrogenous bases.

Explanation:

Levene was an American biochemist who studied the structure of DNA in the early 1900s and in 1920 he found that DNA consists of four nitrogenous bases that are Adenine, Guanine, Thymine, Cytosine.

He also found deoxyribose sugar and phosphate group and said that nucleotide is the basic unit of DNA which contains a ribose sugar with attached nitrogenous base and phosphate group.

He also concludes that an equal amount of adenine, guanine, thymine, and cytosine makes the DNA which is now known as tetranucleotide hypothesis. So the correct answer is b. He determined that DNA contains four nitrogenous bases.  

You might be interested in
9. Which of the following explains why legume plants are less likely than other terrestrial plants to experience nitrogen limita
NARA [144]
Because of the nitrogen cycle all of the above answers are correct
7 0
3 years ago
Read 2 more answers
Which factor causes the greatest increase in an area's flash flood risk?
leonid [27]
Can be a number of things, rain fall quota, climate, population, vegetation..any of those.
5 0
3 years ago
Read 2 more answers
Which of the following correctly pairs an ecological level with an example? Select ALL that apply.A. community - the fish, frogs
ch4aika [34]

Answer:

A. community - the fish, frogs, insects, and aquatic plant species that live in a particular lake

B. individual - a groundhog living in your backyard

C. ecosystem - all of the species of plants and animals and the non-living resources in a tropical forest

Explanation:

A community is defined as a group of populations of two or more different species which inhabit the same area at a certain time.

Individual is defined as one type of organism.

Ecosystem includes communities, the environment, the non-living or abiotic conditions and their influence on living organisms.

5 0
3 years ago
Why does frozen water (ice) float on liquid water
Natali5045456 [20]

Answer:

Because it is a solid that has trapped air with the water molecules in cold temperature thus creating a hard solid.

8 0
3 years ago
Read 2 more answers
In humans, the maintenance of a stable internal temperature is a direct result of
Strike441 [17]

Answer: 1


Homeostasis in terms of temperature within the human body is achieved by reaction to stimulation from the environment. For example, in cold temperatures our bodies shiver to get warm.

4 0
3 years ago
Other questions:
  • Which processes takes place in the cytoplasm of a cell?
    7·2 answers
  • Starch molecules are broken into smaller units known as
    15·1 answer
  • Why was there not a significant difference in the reaction rate with 800 mg of substrate as compared to 400 m. of substrate? Wha
    7·1 answer
  • Which of the following is an example of a chemical change
    14·2 answers
  • Which of the following is a characteristic of a base
    11·1 answer
  • Which shows the levels of organizational hierarchy listed from least complex to most complex?
    9·1 answer
  • Based on the data,which statement describes the most reliable way to encode and transmit data and tells why?
    10·2 answers
  • Linnaeus classified organisms into two kingdoms. How was his system of classification impacted after the invention of the micros
    12·1 answer
  • What is a Vector in West Nile Virus?
    10·1 answer
  • Question 6
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!