the axial skeleton consists of bones in the

ATI TEAS 7

TEAS 7 science practice

1. Which bones are included in the axial skeleton?

A. Head, neck, and trunk
B. Arms and legs
C. Hands and feet
D. All of the above

Correct answer: A

Rationale: The correct answer is A: Head, neck, and trunk. The axial skeleton comprises bones located in the head, neck, and trunk region, such as the skull, vertebral column, and rib cage. These bones provide structural support and protect vital organs like the brain, spinal cord, and heart. Choices B and C are incorrect because arms, legs, hands, and feet are part of the appendicular skeleton, not the axial skeleton. The appendicular skeleton is responsible for movement, manipulation, and mobility, while the axial skeleton primarily provides central support and protection for essential organs.

2. What is the stoichiometric coefficient of nitrogen (N2) in the balanced equation for the Haber process: N2 + 3H2 → 2NH3?

A. 1
B. 2
C. 3
D. 4

Correct answer: A

Rationale: In the balanced equation for the Haber process: N2 + 3H2 → 2NH3, the stoichiometric coefficient of nitrogen (N2) is 1. This means that one molecule of nitrogen reacts with three molecules of hydrogen to produce two molecules of ammonia. The coefficient '1' indicates the mole ratio of N2 in the reaction. Choice B, 2, is incorrect because it represents the coefficient for ammonia (NH3) in the balanced equation. Choice C, 3, is incorrect as it corresponds to the coefficient of hydrogen (H2). Choice D, 4, is not the correct stoichiometric coefficient for nitrogen (N2) in this equation.

3. Which of the following statements regarding heart valves is correct?

A. The atrioventricular valves lie between the atria and the ventricles.
B. The pulmonary semilunar valve lies between the right ventricle and the pulmonary trunk.
C. The atrioventricular valves prevent backflow into the atria when the ventricles contract.
D. All of the above

Correct answer: D

Rationale: All of the statements are correct regarding heart valves. Choice A is accurate as the atrioventricular valves indeed lie between the atria and the ventricles. Choice B correctly identifies the location of the pulmonary semilunar valve. Choice C is true as the atrioventricular valves do prevent backflow into the atria during ventricular contraction. Therefore, selecting 'All of the above' as the correct answer is appropriate as all statements are accurate.

4. Which hormone, produced by the thyroid gland, regulates calcium levels in the blood by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys?

A. Calcitonin
B. Parathyroid hormone (PTH)
C. Thyroxine
D. Insulin

Correct answer: A

Rationale: Calcitonin is the hormone produced by the thyroid gland that regulates calcium levels in the blood. It enhances calcium absorption in the intestines and reduces calcium loss in the kidneys. Parathyroid hormone (PTH) operates oppositely to calcitonin by increasing calcium levels in the blood. Thyroxine is a thyroid gland hormone that primarily regulates metabolism, not calcium levels. Insulin, produced by the pancreas, is responsible for controlling blood sugar levels, not calcium levels. Therefore, the correct answer is Calcitonin as it specifically targets calcium regulation in the body.

5. Which of the following substances is a common base found in household products?

A. Sodium chloride (NaCl)
B. Ammonia (NH₃)
C. Vinegar
D. Lemon juice

Correct answer: B

Rationale: The correct answer is B, Ammonia (NH₃). Ammonia is commonly found in household products and is used in cleaning agents due to its alkaline properties. Sodium chloride (NaCl) is a common salt and not a base. Vinegar is acetic acid, which is acidic in nature. Lemon juice contains citric acid, making it acidic as well. Therefore, ammonia is the only base among the choices provided.