ATI TEAS 7
ATI TEAS 7 Version 1 Science Questions
Extract:
Question 1 of 5
After infecting host cells, how does the AIDS virus, which contains RNA, insert viral DNA into the host T-cell?
Correct Answer: B
Rationale: Reverse transcriptase is an essential enzyme unique to retroviruses like the AIDS virus. It catalyzes the conversion of viral RNA into DNA through a process known as reverse transcription. The newly formed viral DNA is then integrated into the host cell's genome, enabling the virus to replicate and establish a persistent infection within the host.
Extract:
Question 2 of 5
What causes osteoporosis?
Correct Answer: B
Rationale: Osteoporosis is a condition characterized by reduced bone density and mass, leading to brittle bones. Osteoblasts are cells responsible for forming new bone tissue, while osteoclasts break down old or damaged bone. In osteoporosis, there is a decrease in osteoblast activity, causing a net loss of bone as the breakdown surpasses formation. Meanwhile, osteoclast activity remains relatively stable. This imbalance between bone formation (osteoblast activity) and bone resorption (osteoclast activity) contributes to the development of osteoporosis by reducing bone strength and increasing susceptibility to fractures.
Question 3 of 5
Which of the following microorganisms lacks its own metabolic pathways and can only reproduce inside a host cell?
Correct Answer: B
Rationale: The correct answer is B: Viruses. Viruses are obligate intracellular parasites, lacking metabolic pathways and being dependent on a host cell for replication. Unlike bacteria, protozoa, or muscle cells, viruses utilize the host cell's resources and machinery to replicate their genetic material and produce new viral particles.
Extract:
Question 4 of 5
Which of the following properties does soap, an emulsifier, have that make it useful for washing dirt off one's hands with water?
Correct Answer: A
Rationale: Soap acts as an emulsifier due to its dual polar (hydrophilic) and nonpolar (hydrophobic) nature, allowing it to effectively bond oil and water, making option A the correct choic
Extract:
Question 5 of 5
What is the approximate threshold value for mammalian neurons?
Correct Answer: B
Rationale: The approximate threshold value for mammalian neurons is around -55 mV. At this membrane potential, the neuron becomes more excitable and is more likely to generate an action potential. If the membrane potential reaches this level or depolarizes beyond it, it triggers the opening of voltage-gated ion channels, leading to the initiation of an action potential. Values below this threshold are considered subthreshold and do not usually result in action potential generation. Understanding the threshold potential is crucial in assessing the excitability and firing properties of neurons, as it represents the critical point at which the neuron transitions from a resting state to an active state, enabling the transmission of electrical signals.