ATI TEAS Practice Science Test

Correct Answer: A

Rationale: The correct answer is A: They are small and soluble. Small molecules can easily diffuse across cell membranes, while soluble molecules can dissolve in the cell's aqueous environment. This combination allows the signals to pass through the membrane and bind to intracellular receptors. Choice B (large and soluble) is incorrect because large molecules have difficulty crossing the membrane. Choices C (small and insoluble) and D (large and insoluble) are incorrect as they do not facilitate the passage of signals across the cell membrane for binding to intracellular receptors.

Correct Answer: A

Rationale: The correct answer is A: Cranial and spinal. The dorsal cavity is divided into two subdivisions: the cranial cavity, which contains the brain, and the spinal cavity, which houses the spinal cord. This division corresponds to the anatomical locations of these structures within the back of the human body. Explanation: 1. The cranial cavity is located in the skull, specifically protecting the brain. 2. The spinal cavity runs through the vertebral column, safeguarding the spinal cord. 3. These subdivisions are anatomically and functionally distinct, housing vital components of the central nervous system. Summary: B: Dorsal and ventral - Incorrect. Dorsal and ventral refer to the front and back sides of the body, not specific cavities within the back. C: Lateral and proximal - Incorrect. Lateral and proximal describe directions in relation to the body, not cavities within the back. D: Inferior and superior - Incorrect. Inferior and superior

Correct Answer: A

Rationale: The correct answer is A: Adenine. Adenine forms a complementary base pair with cytosine through hydrogen bonding in DNA. This pairing is essential for maintaining the structure and stability of the DNA double helix. Adenine and cytosine form two hydrogen bonds between them. Choices B, C, and D are incorrect because cytosine does not bind with itself (B), guanine (C), or thymine (D) in DNA. Thymine pairs with adenine, while guanine pairs with cytosine. Therefore, the correct base that binds with cytosine is adenine.

Correct Answer: C

Rationale: The correct order of airflow in the lungs is Trachea, Bronchi, Bronchioles, Alveoli (Option C). The rationale is: 1. Air enters through the trachea. 2. Trachea branches into bronchi. 3. Bronchi further divide into bronchioles. 4. Bronchioles lead to the alveoli where gas exchange occurs. Summary: Option A is incorrect as it starts with bronchi before the trachea. Option B is incorrect as it reverses the order of bronchioles and bronchi. Option D is incorrect as it places alveoli before bronchioles and trachea before bronchi.

Correct Answer: D

Rationale: The correct answer is D: Sucrase. Sucrose is a disaccharide composed of glucose and fructose. Sucrase is the enzyme responsible for breaking down sucrose into its constituent sugars, glucose, and fructose. Lactase (A) breaks down lactose, Maltase (B) breaks down maltose, and Peptidase (C) breaks down proteins. In this case, since we are dealing with sucrose from the birthday cake, the enzyme needed is sucrase to catalyze the breakdown of sucrose into its simpler sugars.