what is the primary function of white blood cells

ATI TEAS 7

Practice TEAS Science Test

1. What is the primary function of white blood cells?

A. To carry oxygen
B. To fight infection
C. To transport nutrients
D. To transport waste

Correct answer: B

Rationale: The correct answer is B: "To fight infection." White blood cells are primarily responsible for fighting infections and foreign invaders in the body, making them a critical component of the immune system. Choice A, "To carry oxygen," is incorrect as red blood cells are responsible for oxygen transport. Choice C, "To transport nutrients," is incorrect as this function is mainly attributed to blood plasma and other specialized cells. Choice D, "To transport waste," is also incorrect as waste removal is primarily handled by the kidneys and the lymphatic system, not white blood cells.

2. In the cardiovascular system, what does the term 'double circulation' refer to?

A. The separation of oxygenated and deoxygenated blood flow within the heart.
B. The regulation of blood pressure through vasoconstriction and vasodilation.
C. The cyclic contraction and relaxation of the heart muscle.
D. The existence of two separate circulatory pathways, one for the lungs and one for the body.

Correct answer: D

Rationale: The term 'double circulation' in the cardiovascular system refers to the existence of two separate circulatory pathways, one for the lungs (pulmonary circulation) and one for the body (systemic circulation). Oxygen-poor blood is pumped from the heart to the lungs for oxygenation, and then oxygen-rich blood is pumped from the lungs back to the heart to be circulated to the rest of the body. Choices A, B, and C are incorrect as they do not accurately describe the concept of 'double circulation.' Choice A refers to the separation of oxygenated and deoxygenated blood within the heart, choice B relates to blood pressure regulation mechanisms, and choice C describes the cardiac muscle's contraction and relaxation, none of which define 'double circulation' in the context of the cardiovascular system.

3. What are chromosomes made of?

A. DNA and RNA
B. DNA and protein
C. Protein and RNA
D. DNA and lipids

Correct answer: B

Rationale: Chromosomes are made up of DNA and associated proteins. These proteins help package and organize the DNA within the cell, playing a crucial role in gene regulation and cell division. While RNA is involved in various cellular processes, it is not a primary component of chromosomes. Lipids are not a fundamental component of chromosomes, which primarily consist of DNA and proteins.

4. What is the process of breaking down fatty acids into acetyl-CoA, a key molecule in cellular respiration, called?

A. Beta-oxidation
B. Lipolysis
C. Carbohydrate catabolism
D. Nucleic acid catabolism

Correct answer: A

Rationale: Beta-oxidation is the correct term for the process of breaking down fatty acids into acetyl-CoA molecules. This essential process takes place in the mitochondria and is a pivotal step in fatty acid metabolism for energy production. Lipolysis, however, refers to the breakdown of fats into fatty acids and glycerol but does not specifically involve the conversion of fatty acids into acetyl-CoA. Carbohydrate catabolism focuses on breaking down carbohydrates into glucose for energy production and is not directly linked to the conversion of fatty acids into acetyl-CoA. Nucleic acid catabolism involves the breakdown of nucleic acids into nucleotides and is not associated with the conversion of fatty acids into acetyl-CoA.

5. What is the independent variable in this experiment?

A. Time
B. Dog weight
C. Dog species
D. Dog food type

Correct answer: D

Rationale: The independent variable is the factor that is manipulated by the researcher to observe its effects on the dependent variable. In this experiment, the researcher is likely changing the type of dog food, and this manipulation is what impacts the outcome being measured. Therefore, 'Dog food type' is the independent variable. Choices A, B, and C do not represent the variable being intentionally changed by the researcher, making them dependent variables or other factors not directly controlled or manipulated in this experiment.