The E. coli that normally live in the human large intestines and produce vitamin K that the body uses would be best described as participating in a _______ relationship.
saprobic
commensal
parasitic
mutualistic
The Correct Answer is D
A. saprobic: A saprobic relationship refers to organisms that obtain nutrients by decomposing dead or decaying organic matter. Saprobes, such as many fungi and bacteria, play an important role in environmental nutrient cycling. The E. coli in the human intestine are not primarily decomposing dead tissue but instead living within a host and interacting with host physiology.
B. commensal: In a commensal relationship, one organism benefits while the other is neither significantly helped nor harmed. Although many normal microbiota are considered commensal, intestinal E. coli provide a measurable benefit to the host by synthesizing vitamin K and certain B vitamins. The host receives a physiological benefit, this interaction is more than commensal.
C. parasitic: A parasitic relationship occurs when one organism benefits at the expense of the host, often causing harm or disease. Pathogenic bacteria demonstrate parasitism by damaging tissues, stealing nutrients, or producing toxins. E. coli that reside in the colon as part of the normal microbiota do not harm the host and instead contribute to normal metabolic functions.
D. mutualistic: Mutualism describes a symbiotic relationship in which both organisms benefit. In the human colon, E. coli receive nutrients and a stable environment for growth, while the host benefits from bacterial synthesis of vitamin K, which is essential for blood clotting processes. This reciprocal exchange of benefits characterizes a mutualistic relationship.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
In gram-negative bacteria, the cell envelope is a complex structure composed of three main layers: an inner (cytoplasmic) membrane, a periplasmic space, and an outer membrane. The inner membrane is a phospholipid bilayer that regulates transport and energy production. The periplasmic space lies between the inner and outer membranes and contains a thin layer of peptidoglycan along with enzymes involved in nutrient processing and defense. The outer membrane contains lipopolysaccharides (LPS), porins, and other proteins that provide structural support, act as a barrier to certain antibiotics, and contribute to the organism’s pathogenicity.
100 Multiple Choice 0.5 points
Correct Answer is A
Explanation
A. Resident microbiota: Resident microbiota, also called normal flora, are the stable populations of microorganisms that inhabit various body sites. They play a critical role in maintaining health by competing with pathogenic microbes for nutrients and space, producing antimicrobial substances, and supporting immune system development. When antibiotics disrupt these microbial communities, opportunistic pathogens can overgrow, leading to infections.
B. Viral replication: Viral replication refers to the process by which viruses hijack host cells to produce new viral particles. While this is important in viral infections, it is unrelated to the disruption of intestinal bacteria and the resulting bacterial infections.
C. Endospores: Endospores are dormant, highly resistant structures produced by certain bacteria to survive harsh environmental conditions. While some endospore-forming bacteria (e.g., Clostridioides difficile) can cause disease after microbiota disruption, the key concept demonstrated here is the protective role of resident microbiota rather than the mere presence of endospores.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.