what is the myelin sheath and what does it do
Logo

Nursing Elites

ATI TEAS 7

ATI TEAS 7 science review

1. What is the myelin sheath and what does it do?

Correct answer: B

Rationale: The myelin sheath is a fatty substance that insulates some nerve fibers. It is made up of specialized cells that wrap around the axons of neurons, providing insulation and speeding up the transmission of nerve impulses. Choice A is incorrect as the myelin sheath is not a group of nerve cells but rather a substance that surrounds nerve fibers. Choice C is incorrect as the myelin sheath is not a fluid-filled cavity within the brain. Choice D is incorrect as the myelin sheath is not the junction between two neurons.

2. When testing how quickly a rat dies based on the amount of poison it eats, which of the following is the independent variable and which is the dependent variable?

Correct answer: B

Rationale: The correct answer is B. In this experiment, the independent variable is the amount of poison because it is what is being manipulated by the researcher. The dependent variable is how quickly the rat dies, as it is the outcome that is being measured based on the different amounts of poison administered. Choice A is incorrect because the independent variable should be what is being manipulated or changed, which is the amount of poison in this case. Choice C is incorrect because whether the rat eats the poison is not being varied or controlled by the researcher. Choice D is incorrect because the cage the rat is kept in is not relevant to the relationship being studied between the amount of poison and the rat's survival time.

3. Which type of tissue is characterized by tightly packed cells with minimal extracellular matrix and provides structural support and protection?

Correct answer: A

Rationale: Epithelial tissue is the correct answer as it aligns with the description provided in the question. Epithelial tissue is characterized by tightly packed cells with minimal extracellular matrix, which allows it to form protective barriers on the body's surface and line internal organs, providing structural support and protection. Connective tissue, while important for support and connection between tissues and organs, does not fit the description in the question of being tightly packed with minimal extracellular matrix. Muscle tissue is responsible for movement, and nervous tissue transmits signals throughout the body, neither of which are primarily involved in providing structural support and protection as described. Therefore, based on the characteristics described in the question, epithelial tissue best fits the description of tissue that provides structural support and protection.

4. What is the term for a genetic disorder caused by a mutation in a mitochondrial gene?

Correct answer: D

Rationale: A) Autosomal dominant disorder: This type of genetic disorder is caused by a mutation in one copy of an autosomal gene. It is not related to mitochondrial gene mutations. B) Autosomal recessive disorder: This type of genetic disorder is caused by mutations in both copies of an autosomal gene. It is not related to mitochondrial gene mutations. C) Sex-linked disorder: This type of genetic disorder is caused by mutations in genes located on the sex chromosomes (X or Y). It is not related to mitochondrial gene mutations. D) Mitochondrial disorder: Mitochondrial disorders are genetic disorders caused by mutations in genes located in the mitochondria, the energy-producing structures within cells. These disorders are inherited maternally and can affect various organs and systems in the body due to the role of mitochondria in energy production.

5. Which organ is responsible for detoxifying harmful substances in the body?

Correct answer: B

Rationale: The correct answer is the Liver. The liver is the organ responsible for detoxifying harmful substances in the body. It accomplishes this by metabolizing drugs and filtering blood. The liver plays a crucial role in maintaining overall health by processing and eliminating toxins. Choices A, C, and D are incorrect. The kidneys primarily filter blood to remove waste and excess substances, the heart is responsible for pumping blood throughout the body, and the pancreas aids in digestion and regulating blood sugar levels, but none of these organs are primarily responsible for detoxification.

Similar Questions

Elements tend to gain or lose electrons to achieve stable electron configurations like those of noble gases. Their group number often indicates the number of electrons gained/lost and the resulting ionic charge, providing a good starting point for prediction.
Which of the following immune cells are part of the innate immune response?
If a patient had a heart attack and tissue in the left ventricle lost blood flow, what would you most expect to happen?
Which term describes the allele for green eyes?
Which of the following is used to record the measurable electrical activity of the brain?

Access More Features

ATI TEAS Premium Plus
$150/ 90 days

  • Actual ATI TEAS 7 Questions
  • 3,000 questions with answers
  • 90 days access

ATI TEAS Basic
$99/ 30 days

  • 3,000 Questions with answers
  • 30 days access

Other Courses