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Paladinen [302]
4 years ago
5

Which of the following reactions with covalently closed, circular DNA (cccDNA) does NOT result in a new linking number? A. incub

ation with a type II topoisomerase B. incubation with a type I topoisomerase C. incubation with ethidium D. brief incubation with DNase I followed by resealing the breaks in the
phosphodiester backbone with another enzyme (DNA ligase)
Medicine
2 answers:
alisha [4.7K]4 years ago
8 0

Answer:

Okay

Explanation:

Human topoisomerase I plays an important role in removing positive DNA supercoils that accumulate ahead of replication forks. It also is the target for camptothecin-based anticancer drugs that act by increasing levels of topoisomerase I-mediated DNA scission. Evidence suggests that cleavage events most likely to generate permanent genomic damage are those that occur ahead of DNA tracking systems. Therefore, it is important to characterize the ability of topoisomerase I to cleave positively supercoiled DNA. Results confirm that the human enzyme maintains higher levels of cleavage with positively as opposed to negatively supercoiled substrates in the absence or presence of anticancer drugs. Enhanced drug efficacy on positively supercoiled DNA is due primarily to an increase in baseline levels of cleavage. Sites of topoisomerase I-mediated DNA cleavage do not appear to be affected by supercoil geometry. However, rates of ligation are slower with positively supercoiled substrates. Finally, intercalators enhance topoisomerase I-mediated cleavage of negatively supercoiled substrates but not positively supercoiled or linear DNA. We suggest that these compounds act by altering the perceived topological state of the double helix, making underwound DNA appear to be overwound to the enzyme, and propose that these compounds be referred to as ‘topological poisons of topoisomerase I’

Natasha2012 [34]4 years ago
3 0

Answer:incubation with ethidium

Explanation:

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The primary care nurse practitioner is examining a 5-year-old child who has had recurrent fevers, bone pain, and a recent loss o
Lina20 [59]

Answer: the nurse will refer this child to a specialist for a bone marrow biopsy.

Explanation:

From the symptoms which where observed by the primary health care provider, the child had recurrent fevers, bone pain, and a recent loss of weight. While the physical examination revealed scattered petechiae, lymphadenopathy, and bruising. On further Laboratory diagnosis of the blood film, the full blood count revealed:

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The major importance of full blood count is to evaluate the general health and detect a variety of of disorders. Since the blood picture is not normal, the health care provider should refer the child for BONE MARROW BIOPSY.

This is because the blood cells are produced from the bone marrow. Bone marrow biopsy is a test done to show if the bone marrow is healthy and able to make normal amount of blood cells.

The results of the bone marrow biopsy will help the primary care nurse to determine the cause of the abnormalities seen in the blood picture and will give the best directions to follow for an appropriate diagnosis and treatment.

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A person lying with his/her face down is said to be in what position?
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Option(B) is the correct answer.

A <u>person lying with his/her face down</u> is said to be in prone posture.

<h3>What do we know about prone posture?</h3>

With the start of the pandemic in March 2020, proning—a technique that had been used for years in the United States to place patients in intensive care who were experiencing respiratory issue on their stomachs—began to become widely used. Proning was briefly presented in certain blog postings shortly after, with the following disclaimer to clarify the type of evidence supporting its usage in SARS-CoV-2 patients.

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the patella tendon

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How birth rates and death rates influence the number of organisms in an ecosystem.
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Answer:

Explanation:

If the birth rate exceeds (is greater than) the death rates, then the population of that organism species will increase.  If the death rate exceeds the birth rate, then the population will decrease.

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Where should the nurse instill an ophthalmic medication in a 6-year-old child?
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The structures surrounding the eyes and acute or chronic eye disorders are treated using eye drops and ointments. As they are supplied directly to their site of action and are consequently more effective than drugs taken orally, they constitute the cornerstone of treatment for eye illness.

Topical eye treatment must be given the same priority as medications that are taken systemically in order for patients to get the most therapeutic benefit.

In order to properly administer topical medications, nurses, patients, and caregivers must have a solid awareness of their therapeutic effects and any potential side effects.

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