The correct answer is A
The scientist can determine that this nucleic acid is a DNA molecule, because it contains Thymine, which does not occure in the RNA molecule. The RNA molecule contains Adenine, Guanine and Cytosine just like the DNA, but unlike the DNA it contains Uracil, not Thymine.
Secondly, the scientist can say with certainty that this DNA molecule is surrounded by a nucleus based on the structure of the nucleic acid described. Only eukaryotic cells have ladder structure. The prokaryotic cells have circular DNA and do not have any organelles, like the nucleus. Therefore, from the ladder structure of the DNA the scientist can see that the cell has a nucleus.
Answer:
Presence of specific antigen receptors on the surface of Immunocompetent B and T cells make them to generate immune response against specific antigens only.
Explanation:
The cellular and antibody-mediated immune responses are specific in nature. This means these immune responses are generated for particular foreign molecules or antigens only. These immune responses include B and T lymphocytes. Before T cells leave the thymus or B cells leave the red bone marrow, they develop immunocompetence. Immunocompetence is the ability to carry out adaptive immune responses. During this process. B cells and T cells make distinctive proteins and insert them into their plasma membranes. Some of these proteins function as antigen receptors capable of recognizing specific antigens. This is why the B and T cell-mediated third line of defense are specific in nature.
For example, antibody-mediated immune responses generate the memory cells for most previously encountered antigens to ensure the generation of more rapid and vigorous response during any further encounter with the same antigen.
Answer:
Nonrenewable resources are used to help provide humans with the energy they need to power their homes, cars, and Fourth of July barbeques. They're an important part of the worldwide economy because they're some of the most common ways we get the energy we need to power our lives.
Explanation:
Answer:
All viruses reproduce <em>by getting host cells to make new viruses</em><em>.</em>
<em>hope</em><em> </em><em>it</em><em> </em><em>help</em><em>s</em><em>!</em>
Explanation:
They live in the host and reproduction occurs there only.
The artery that branches into the common hepatic artery, splenic artery, and left gastric artery is called: Celiac artery.
Cardiac cycle refers to a complete heart-beat of the mammalian heart which comprises sequential alternating contraction and relaxation of the artery and ventricle; thereby, causing blood to flow unidirectionally (in one direction) throughout the body of a living organism such as a human being.
An artery can be defined as a blood vessel that is saddled with the responsibility of carrying oxygen-rich blood from the heart to organs and tissues in the body of a living organism.
A celiac artery is also referred to as a celiac trunk or celiac axis and it can be defined as a major splanchnic artery in the abdominal cavity that supplies blood for:
Basically, the celiac artery is an artery which branches into multiple arteries such as the common hepatic artery, splenic artery, and left gastric artery.
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