which part of the digestive system is primarily responsible for absorbing nutrients

ATI TEAS 7

Practice Science TEAS Test

1. Which part of the digestive system is primarily responsible for absorbing nutrients?

A. Stomach
B. Small intestine
C. Esophagus
D. Large intestine

Correct answer: B

Rationale: The small intestine is the primary site for nutrient absorption in the digestive system. It is lined with specialized cells that facilitate the absorption of nutrients such as carbohydrates, proteins, fats, vitamins, and minerals into the bloodstream for distribution throughout the body. While the stomach plays a role in digestion by breaking down food with acid and enzymes, the actual absorption of nutrients occurs mainly in the small intestine. The esophagus is responsible for transporting food from the mouth to the stomach, but it does not absorb nutrients. The large intestine primarily absorbs water and electrolytes, not nutrients.

2. What is the role of RNA in the regulation of gene expression?

A. Provides energy for the process
B. Controls the timing and location of protein synthesis
C. Translates the genetic code into amino acids
D. Stores genetic information

Correct answer: B

Rationale: A) RNA does not provide energy for the process of gene expression. Energy is typically provided by molecules like ATP. B) RNA plays a crucial role in controlling the timing and location of protein synthesis through processes like transcriptional regulation, RNA splicing, and post-transcriptional modifications. It helps determine when and where specific proteins are produced in the cell. C) While mRNA translates the genetic code into amino acids during the process of translation, this is not the primary role of RNA in the regulation of gene expression. D) RNA does not store genetic information in the same way that DNA does. DNA is the molecule responsible for storing genetic information in the form of genes. Therefore, option B is the most appropriate choice as it accurately describes the role of RNA in regulating gene expression.

3. Diabetes mellitus is a chronic condition affecting blood sugar control. What is the main type of hormone deficiency associated with type 1 diabetes?

A. Insulin
B. Glucagon
C. Estrogen
D. Testosterone

Correct answer: A

Rationale: The correct answer is A: Insulin. Type 1 diabetes is characterized by the body's inability to produce insulin, the hormone responsible for regulating blood sugar levels. Insulin deficiency in type 1 diabetes leads to high blood sugar levels as the body cannot effectively utilize glucose for energy. Glucagon (Choice B) is a hormone that works opposite to insulin, raising blood sugar levels. Estrogen (Choice C) and testosterone (Choice D) are not directly involved in blood sugar control or the pathophysiology of type 1 diabetes.

4. What is the process of changing from a liquid to a gas called?

A. Freezing
B. Condensation
C. Vaporization
D. Sublimation

Correct answer: C

Rationale: The correct answer is C: Vaporization. Vaporization is the process by which a substance changes from a liquid state to a gas state. Choice A, Freezing, is incorrect as it refers to the process of changing from a liquid to a solid. Choice B, Condensation, is incorrect as it describes the process of changing from a gas to a liquid. Choice D, Sublimation, is incorrect as it involves changing directly from a solid to a gas without passing through the liquid state.

5. What is a lysosome?

A. A sac-like structure that contains enzymes that break down cellular components
B. A network of tubules that transport proteins and lipids throughout the cell
C. The site of protein synthesis
D. The site of cellular respiration

Correct answer: A

Rationale: A lysosome is a membrane-bound organelle found in animal cells that contains digestive enzymes. These enzymes are responsible for breaking down various cellular components, such as proteins, lipids, carbohydrates, and even foreign particles like bacteria. This breakdown process is crucial for maintaining cell health and function by recycling and disposing of cellular waste. Options B, C, and D are incorrect because lysosomes are not involved in transporting proteins and lipids throughout the cell (option B), protein synthesis (option C), or cellular respiration (option D). Lysosomes primarily function as the cell's 'recycling center' by breaking down and processing cellular materials.