Answer:
The nucleic acid is a macromolecule present in living systems in the form of either DNA or RNA, whose molecule consists of many nucleotides which are linked with each other to form long chains. The presence of DNA or RNA in an individual promotes continuity of life. The variability and complexity of nucleic acid are dependent on its constituent molecules as, sugar, a phosphate group, and a nitrogenous base. However, two monocyclic nitrogenous bases were classified purines (adenine:A, guanine:G) and pyrimidines (thymine:T, cytosine:C, and uracil:U).
In addition, RNA is a single-stranded structure which differs from DNA in two aspects, the sugar content of RNA is ribose, and pyrimidine base uracil replaces the thymine base of DNA. A ratio between two strands of DNA can be calculated by using Chargrff's rule which states that "DNA from any cell of all organisms possess a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases'.
The purine to pyrimidine ratio in RNA with different bases is given below in the following table:
Presence of single strand in RNA does not follow chargaff's rule and alters the purine: pyrimidine ratio. The above ratio of each base in the given information is not equal, due to which the ratio of purines to pyrimidines is different. The ratio of DNA and RNA is not equal because DNA has its complementary DNA strand. However, bases in RNA might vary due to its single-strandedness property, but its ratio is dependent on the species.
Therefore, it can be concluded that the ratio of purines to pyrimidines is dependent on the species due to its genetic makeup. Hence, option (c) is correct.
The answer is Genes on the same chromosome are sometimes inherited disparately. I had the exact same question and that was the answer hope this helped! Have a good day!
Answer:
This question lacks options, options are:
A.They maintain the cell’s shape.
B.They regulate cell processes.
C.They protect the body from infectious agents.
D.They signal the immune system to destroy pathogens.
E.They speed up biochemical reactions.
F.They send electrical signals.
The correct answers are C and D.
Explanation:
B cells and T cells use different biological weapons to attack the pathogen. The first secrete proteins called antibodies, which are distributed via the blood or the exposed surfaces to the environment, such as mucous. Antibodies are glycoproteins that circulate in the bloodstream looking for antigens that cause some type of damage to the body. Antibodies recognize and neutralize pathogens in a highly efficient way. Once the antibodies are produced, they remain circulating in the bloodstream for several months, which generates immunity for a long period of time to a certain antigen, in other words, they are capable of recognizing other molecules (antigens) in a very specific way and forming stable complexes with them (immune complexes). Its appearance in plasma is part of the adaptive immune response, in what is known as a specific humoral response, constituting a very effective defense against pathogens.