which of the following describes the primary function of the pyloric sphincter

ATI TEAS 7

TEAS 7 Science Practice Test

1. What is the primary function of the pyloric sphincter?

A. to regulate the movement of food material from the stomach to the duodenum
B. to neutralize stomach acid
C. to prevent digested food materials and stomach acid from entering the esophagus
D. to begin the process of chemical digestion

Correct answer: A

Rationale: The primary function of the pyloric sphincter is to regulate the flow of partially digested food material (chyme) from the stomach into the small intestine, specifically the duodenum. This control is essential for proper digestion and absorption of nutrients in the small intestine. Choices B, C, and D are incorrect. Choice B is incorrect because neutralizing stomach acid is primarily the function of the stomach lining and antacid mechanisms. Choice C is incorrect because preventing the backflow of digested food materials and stomach acid into the esophagus is mainly the role of the lower esophageal sphincter. Choice D is incorrect because the chemical digestion process primarily starts in the stomach through the action of gastric juices, not the pyloric sphincter.

2. The brain is part of which system?

A. Integumentary system
B. Nervous system
C. Endocrine system
D. Respiratory system

Correct answer: B

Rationale: The brain is a crucial organ that serves as the command center of the body, making it a key component of the nervous system. It processes sensory information, coordinates movements, and regulates various bodily functions. Therefore, the brain is correctly categorized as part of the nervous system. Choices A, C, and D are incorrect because the integumentary system pertains to the skin, the endocrine system involves hormone regulation, and the respiratory system is responsible for breathing. These systems do not encompass the brain's functions or structure.

3. Which of the following statements is NOT true of most metals?

A. Most of them are good conductors of heat.
B. Most of them are gases at room temperature.
C. Most of them are ductile.
D. They make up the majority of elements on the periodic table.

Correct answer: B

Rationale: The correct answer is B because most metals are not gases at room temperature; they are usually solid and good conductors of heat. Metals are generally known for being good conductors of heat, ductile, and making up the majority of elements on the periodic table. Choice A is correct as metals, in general, are good conductors of heat. Choice C is also correct as most metals exhibit ductility. Choice D is correct as metals constitute the majority of elements found on the periodic table.

4. What is the role of DNA in heredity?

A. Provides energy for the cell
B. Determines the structure and function of proteins
C. Stores and transmits genetic information
D. Controls cell division

Correct answer: C

Rationale: DNA (deoxyribonucleic acid) is a molecule that carries the genetic instructions used in the growth, development, functioning, and reproduction of all living organisms. It stores genetic information in the form of a code made up of four chemical bases: adenine (A), thymine (T), cytosine (C), and guanine (G). This genetic information is passed down from parents to offspring and is responsible for determining an organism's traits and characteristics. DNA's primary role is to store and transmit genetic information, making option C the correct answer. DNA does not provide energy for the cell (option A), determine the structure and function of proteins (option B), or control cell division (option D).

5. Where does cellular respiration, the process of converting chemical energy into ATP, take place in eukaryotic cells?

A. Nucleus
B. Ribosomes
C. Mitochondria
D. Golgi apparatus

Correct answer: C

Rationale: Cellular respiration, the process of converting chemical energy into ATP, takes place in the mitochondria of eukaryotic cells. The mitochondria are known as the powerhouse of the cell because they are responsible for generating most of the cell's ATP through the process of cellular respiration. This process involves the breakdown of glucose and other organic molecules to produce ATP, which is the primary energy currency of the cell. The other organelles listed in the options (nucleus, ribosomes, and Golgi apparatus) do not play a direct role in cellular respiration. The nucleus is responsible for storing genetic material, ribosomes are involved in protein synthesis, and the Golgi apparatus is involved in processing and packaging proteins for secretion or internal use.