Answer:
b. determine the evolutionary relationships among species
Explanation:
Biologists through the analysis of characters obtained from molecular, morphological, embryological, physiological and behavioral analyzes look for the relationship between species and their origin.Through these coincidences phylogenetic trees are made.
Answer: B) energy released from exergonic reactions.
Explanation:
Cell metabolism is the set of reactions that occur in the cellular environment to synthesize or degrade biomolecules to produce energy. Synthesis metabolism of biomolecules is known as anabolic (anabolism) and catabolic degradation (catabolism).
Endergonic reaction (product has more energy than reagents) and requires energy to occur. Anabolism occurs when the cell has sufficient energy or substrate. Catabolism, in turn, occurs in situations in which the body needs energy, such as between meals and fasting.
The reactions of anabolism and catabolism are opposite but occur in an articulated manner, allowing the maximization of available energy. Thus, while catabolism occurs spontaneously, an exergonic reaction with ATP production, anabolism is non-spontaneous, or endergonic, requiring energy to occur. In other words energy that drives endergonic reactions is often obtained from B) energy released from exergonic reactions.
Answer:
Skin cancer refers to the abnormal activity of skin cells associated with carcinogenesis
Explanation:
This disease is associated with the DNA damage (mutations) often caused by the irrational exposition to UV sun rays that trigger DNA mutations capable of both inactivating tumor suppresor genes and activating oncogenes
The nurse should anticipate the use of antiviral comination in the management of this patient ( <span>peginterferon alfa-2a and </span>ribavirin). This will help
reduce further damage to the liver. A repeat test should be conducted to
indicate whether the virus is cleared.
Answer/Explanation:
DNA polymerase is the enzyme responsible for replicating DNA. It is hugely important that is performs its functions accurately, as if incorrect bases are incorporated this can lead to mutations that disrupt the structure and function of genes. It adds nucleotides in a 5' - 3' direction only.
DNA polymerase III also has high processivity, which means that for every time it binds DNA, it is able to add many bases before it becomes dissociated.
A. DNA polymerase avoids the incorporation of improperly paired nucleotides in two ways:
- The first way depends on the structure of the enzyme. If the nucleotide that the enzyme is in the process of adding is not complementary to the template, then the nucleotide will not align with the template, and thus it is more inefficient to add. This inefficiency means the nucleotide is more likely to leave the active site before it is added, and DNA polymerase can replace it with the correct nucleotide.
- It also has proofreading capabilities. This means, when an incorrect base is added, it recognises the error and can fix this. It can do this because it possesses 3'-5' exonuclease activity. That means, it can chop out incorrectly added bases.
B. Ribonucleotides are the nucleotides that are incorporated into a growing RNA molecule. They are different from deoxyribonucleotides because of the differences in the sugar backbone (ribose vs deoxyribose). Their incorporation would disrupt the structure and function of the DNA, leading to problems with transcription and replication.
DNA polymerase avoids incorporating these nucleotides primarily because of the structure of the enzyme. Ribonucleotides cannot fit into the active site of DNA polymerase due to what is called a "steric filter" or "steric gate". This gate/filter function is performed by specific amino acid residues which usually have a bulky side chain and thus block the incorporation of the 2'OH of the ribose sugar (which is lacking in the deoxyribose sugar)
