how many ml to the appropriate number of significant figures of a 0 m stock solution of hcl should be added to water to create 250 ml of a 50 m soluti

ATI TEAS 7

ATI TEAS Science Practice Test

1. How many mL of a 0 M stock solution of HCl should be added to water to create 250 mL of a 50 M solution of HCl?

A. 31.25 mL
B. 32 mL
C. 30 mL
D. 31.3 mL

Correct answer: B

Rationale: To prepare 250 mL of a 50 M solution of HCl, the formula V1 x C1 = V2 x C2 is used, where V1 is the volume of the stock solution, C1 is the concentration of the stock solution, V2 is the final volume of the desired solution, and C2 is the final concentration of the desired solution. Given V1 x 0 M = 250 mL x 50 M, solving for V1 results in V1 = (250 mL x 50 M) / 0 M = 32 mL. Therefore, 32 mL of the 0 M stock solution of HCl needs to be added to water to create a 250 mL solution of 50 M HCl. Choices A, C, and D are incorrect because they do not represent the accurate volume required for the dilution calculation based on the given concentrations and volumes in the problem.

2. Which of the following areas has the least amount of sweat glands?

A. Back
B. Palms
C. Axilla
D. Forehead

Correct answer: B

Rationale: The correct answer is B - Palms. The palms have the least amount of sweat glands compared to the other options listed. The back, axilla (armpits), and forehead are all areas with a higher concentration of sweat glands in the body. The palms have fewer sweat glands to minimize water loss and maintain a better grip for activities requiring precise and controlled movement. The back, axilla, and forehead have more sweat glands to assist in thermoregulation and cooling of the body, while the palms have fewer sweat glands for functional reasons related to grip and dexterity.

3. Which type of tissue protects the respiratory system's trachea?

A. Bone
B. Cartilage
C. Collagen
D. Keratin

Correct answer: B

Rationale: Cartilage is the correct answer as it provides flexible support and protection in the trachea. Cartilage is specifically designed to maintain the trachea's shape and prevent it from collapsing during breathing. Bone is a rigid tissue, not found in the trachea, and would not provide the necessary flexibility for breathing. Collagen is a structural protein but does not offer the same support and flexibility as cartilage in this context. Keratin is a protein that forms structures like hair and nails, and it is not present in the trachea to provide protection.

4. How do DNA and RNA function together as part of the human genome?

A. DNA carries genetic information from RNA to the cell cytoplasm.
B. RNA carries genetic information from DNA to the cell cytoplasm.
C. DNA and RNA carry genetic information from the cell nucleus to the cytoplasm.
D. DNA and RNA do not interact within the cell.

Correct answer: B

Rationale: The correct answer is B. RNA acts as a messenger carrying genetic instructions from the DNA in the nucleus to the cytoplasm, where proteins are synthesized. This process is known as transcription and translation, where DNA provides the blueprint for protein synthesis, and RNA delivers this information to the cellular machinery in the cytoplasm. Choice A is incorrect as it inaccurately states that DNA carries genetic information from RNA, which is the opposite of the actual flow of information. Choice C is incorrect as it suggests that both DNA and RNA together carry genetic information from the nucleus to the cytoplasm, which is not accurate. Choice D is incorrect as DNA and RNA do interact within the cell, playing crucial roles in genetic information processing and protein synthesis.

5. What is the dermis composed of?

A. Adipose tissue
B. Epithelial cells
C. Connective tissue
D. Muscle tissue

Correct answer: C

Rationale: The correct answer is C: Connective tissue. The dermis is primarily composed of connective tissue, which includes collagen and elastin fibers that provide strength and elasticity to the skin. It houses blood vessels, nerve endings, hair follicles, and glands, playing a crucial role in supporting the skin structure and function. Adipose tissue (choice A) is found in the subcutaneous layer beneath the dermis, providing insulation and energy storage. Epithelial cells (choice B) form the outermost layer of the skin called the epidermis. Muscle tissue (choice D) is not a significant component of the dermis but is found deeper in the body associated with movement and support.