which locations in the digestive system are sites of chemical digestion i mouth ii stomach iii small intestine

ATI TEAS 7

ATI TEAS Science Practice Test

1. Which locations in the digestive system are sites of chemical digestion? I. Mouth II. Stomach III. Small Intestine

A. II only
B. III only
C. II and III only
D. I, II, and III

Correct answer: D

Rationale: Chemical digestion occurs in all three locations in the digestive system - the mouth, stomach, and small intestine. Enzymes in the saliva break down carbohydrates in the mouth, gastric juices in the stomach help break down proteins, and enzymes in the small intestine further break down macronutrients like carbohydrates, proteins, and fats. The mouth initiates the digestion of carbohydrates, the stomach digests proteins, and the small intestine continues the breakdown of carbohydrates, proteins, and fats. Choice A is incorrect because chemical digestion does occur in the mouth. Choice B is incorrect as both the stomach and small intestine are sites of chemical digestion. Choice C is incorrect as the mouth is also a location of chemical digestion, not just the stomach and small intestine.

2. What is the primary function of ribosomes in the cell?

A. To synthesize lipids and other cellular components
B. To package and transport proteins
C. To break down macromolecules
D. To translate mRNA into proteins

Correct answer: D

Rationale: Ribosomes are cellular organelles responsible for protein synthesis. They read the genetic information encoded in messenger RNA (mRNA) and use this information to assemble amino acids into a specific sequence, forming a protein. This process is known as translation and is essential for the production of proteins that carry out various functions in the cell. Options A, B, and C are incorrect as they do not accurately describe the primary function of ribosomes. Choice A is incorrect because the synthesis of lipids and other cellular components is not the primary function of ribosomes. Choice B is incorrect as packaging and transporting proteins are functions typically associated with the endoplasmic reticulum and Golgi apparatus. Choice C is incorrect because ribosomes do not break down macromolecules; instead, they are involved in building proteins from amino acids.

3. What is the periodic table?

A. A table of elements that are arranged in order of increasing atomic number.
B. A table of elements that are arranged in order of increasing atomic mass.
C. A table of elements that are arranged in order of their reactivity.
D. A table of elements that are arranged in order of their color.

Correct answer: A

Rationale: The periodic table is a tabular arrangement of the chemical elements, organized based on their atomic number, electron configurations, and recurring chemical properties. Elements are placed in rows (periods) and columns (groups) with similar properties. The elements are listed in order of increasing atomic number, which is the number of protons in the nucleus of an atom. This arrangement reveals a periodic repetition of chemical properties, forming the basis of the periodic law. Choice B, which suggests arranging elements based on increasing atomic mass, is incorrect because the periodic table is primarily organized by atomic number, not atomic mass. Choices C and D are also incorrect as the periodic table is not based on reactivity or color of elements, but rather on atomic number and properties.

4. What is the difference between DNA and RNA?

A. Both are double-stranded.
B. DNA contains deoxyribose sugar, while RNA contains ribose sugar.
C. RNA contains the nitrogenous base uracil, while DNA contains thymine.
D. Both are identical molecules.

Correct answer: B

Rationale: A) Incorrect. DNA is double-stranded, but RNA is typically single-stranded. B) Correct. DNA contains deoxyribose sugar, which lacks an oxygen atom on the 2' carbon of the sugar ring, while RNA contains ribose sugar, which has an additional hydroxyl group on the 2' carbon. C) Incorrect. RNA contains the nitrogenous base uracil, while DNA contains thymine. D) Incorrect. DNA and RNA have distinct structures and functions, so they are not identical molecules.

5. Which of the following is a function of the liver?

A. Producing digestive enzymes
B. Storing bile
C. Filtering waste products from the blood
D. Transporting nutrients to cells

Correct answer: B

Rationale: The correct function of the liver is to store bile. Bile is produced in the liver and stored in the gallbladder until it is needed to aid in the digestion of fats. While the liver does produce bile, its primary role is to store and release it. Choices A, C, and D are incorrect. Producing digestive enzymes is mainly the function of the pancreas, filtering waste products from the blood is primarily done by the kidneys, and transporting nutrients to cells is typically associated with the circulatory system rather than the liver.