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.
Answer:
Wheat and corn are common products of tropical plantations.
Two abiotic forms of carbon are CARBON DIOXIDE AND METHANE.
The element carbon is continuously been recycled in nature. The abiotic components of the carbon cycle refers to the non living part of the carbon cycle which has influence on the living part. Methane is a type of fossil fuel whose major component is carbon.
The chemical formula of carbon dioxide is CO2 while that of methane is CH4.
A facultative anaerobe.
Explanation:
Anaerobes are organisms which can produce energy via the process of fermentation in the absence of oxygen. The anaerobes can be classified as facultative anaerobes and obligate anaerobes.
Facultative anaerobes are those which can carry out respiration in presence of oxygen but can choose to follow the fermentation pathway if oxygen is absent. Fermentation also uses glucose.
Aerobic respiration produces 32 molecules of ATP from one molecules of glucose while fermentation produces only 2 molecules of ATP . Thus when the organism switches to fermentation pathway it utilizes more and more glucose to reach its energy demands.
Considering all the above points we can conclude that observations indicate that the organism is a facultative anaerobe.
The receptor molecule is the ones which allow different interaction to occur between the matrix and the cell.
<u>Explanation:</u>
Receptor molecules are the protein molecules that have the ability to bind the signaling molecules at the surface of the cell in order to send signals to the matrix. Those signals on receipt<em> </em>act as the channel of communication.
Thereby, the interaction between the cell and matrix is established. Usually, this is one of the kinds of interaction. Paracrine interactions are interaction within adjacent cells whereas the endocrine interactions are interaction with distant cells.
