ATI TEAS 7 Science Practice Test

Correct Answer: A

Rationale: The correct answer is A: Alveoli. Gas exchange occurs in the alveoli, which are tiny air sacs in the lungs. Oxygen from the air we breathe diffuses into the blood vessels surrounding the alveoli, while carbon dioxide from the blood diffuses into the alveoli to be exhaled. The bronchi, larynx, and pharynx are all part of the respiratory system but are not directly involved in gas exchange. The bronchi are airways that lead to the lungs, the larynx is the voice box, and the pharynx is the throat. These structures are important for breathing and vocalization but do not participate in the exchange of gases between the respiratory system and the circulatory system.

Correct Answer: C

Rationale: The correct answer is C, Mitochondria. Mitochondria are often referred to as the powerhouse of the cell as they produce energy in the form of ATP through cellular respiration. This process is essential for various cellular functions, making mitochondria crucial for energy production within the cell. Choice A, Nucleus, is incorrect as the nucleus is responsible for housing the cell's genetic material and controlling cellular activities but not for energy production. Choice B, Cell membrane, is incorrect as it is primarily involved in maintaining cell integrity and regulating the passage of substances in and out of the cell, not in energy production. Choice D, Cytoplasm, is incorrect as it is the jelly-like substance that fills the cell and is the site of many metabolic pathways, but it is not the specific organelle responsible for energy production.

Correct Answer: C

Rationale: The correct answer is C: Pulmonary artery. The pulmonary artery carries deoxygenated blood from the heart to the lungs for oxygenation. This blood is considered the least oxygenated in the body as it has just returned from circulating through the body's tissues and is in need of oxygen replenishment. Choice A, the aorta, is incorrect as it carries oxygenated blood from the heart to the rest of the body. Choice B, the vena cava, carries deoxygenated blood from the body back to the heart. Choice D, the femoral vein, also carries deoxygenated blood back to the heart from the lower extremities.

Correct Answer: B

Rationale: The correct answer is 'B: Recessive.' In genetics, eye color is determined by multiple genes, with green eyes often being associated with a recessive allele. When an individual carries two copies of the recessive allele for green eyes, they will express this eye color. Dominant alleles are expressed over recessive alleles. Homozygous refers to having two identical alleles for a particular gene, and heterozygous refers to having two different alleles. In this context, the allele for green eyes is recessive, meaning it is expressed only when an individual carries two copies of this specific allele. Therefore, 'Recessive' is the most appropriate term to describe the allele for green eyes, making it the correct answer.

Correct Answer: B

Rationale: The correct answer is B: Protein molecules. Enzymes are biological catalysts made up of proteins. They function by facilitating and speeding up chemical reactions in living organisms. Therefore, enzymes are primarily composed of protein molecules, not water, tripolar, or inorganic molecules. Choice A (Water molecules), Choice C (Tripolar molecules), and Choice D (Inorganic molecules) are incorrect because enzymes are specifically classified as proteins due to their structure and function in biological systems.