Science TEAS Practice Test

Correct Answer: C

Rationale: The correct answer is C: The pancreas. The pancreas functions as both an endocrine and exocrine gland. It secretes digestive enzymes (exocrine function) into the small intestine and produces hormones such as insulin and glucagon (endocrine function). This dual role allows the pancreas to regulate both digestion and blood sugar levels. Incorrect Answers: A: The kidney - Functions mainly in filtration and regulation of fluid balance, not as an endocrine/exocrine gland. B: The spleen - Primarily involved in immune function and blood filtration, not as an endocrine/exocrine gland. D: The stomach - Secretes digestive enzymes, but does not have a significant endocrine function like the pancreas.

Correct Answer: A

Rationale: The correct answer is A: The human body has evolved to become more resilient to its environment. This statement is not likely to have contributed to the longer life expectancy in the 21st century. Evolution occurs over long periods of time, not within a span of a few hundred years. Advances in medical technology and treatments (B), higher standards of basic cleanliness (C), and the creation of vaccines (D) have all played significant roles in increasing life expectancy by preventing and treating diseases, improving overall health, and reducing mortality rates. These factors are directly linked to improvements in healthcare and sanitation practices, which have had a tangible impact on life expectancy.

Correct Answer: A

Rationale: The correct answer is A: The sinoatrial node. The SA node is known as the heart's natural pacemaker as it initiates electrical impulses that regulate the heart rate. It is located in the right atrium and generates rhythmic electrical signals that stimulate the cardiac muscle to contract. The left ventricle (B), aorta (C), and tricuspid valve (D) do not serve as electrical stimulators of the cardiac muscle. The left ventricle is a chamber that pumps oxygenated blood, the aorta is the largest artery that carries blood away from the heart, and the tricuspid valve controls blood flow between the right atrium and right ventricle.

Correct Answer: A

Rationale: The correct answer is A: Dense bone. Dense bone is not one of the major types of bones in the human body. Long bones, short bones, and irregular bones are the three major types. Long bones are characterized by being longer than they are wide, like the femur. Short bones are cube-shaped, like the carpals in the wrist. Irregular bones have complex shapes and are typically found in the spine and face. Dense bone is not a separate category but rather a classification based on the density of bone tissue. It refers to the outer layer of compact bone found in all bone types. Therefore, A is the correct answer because dense bone is not a distinct major type of bone in the human body.

Correct Answer: D

Rationale: The correct answer is D: Plasma cells. Plasma cells are a type of white blood cell that produces and secretes antibodies, which are essential for the immune response. Plasma cells are specifically designed to produce antibodies to fight off infections. Bacterial cells (choice A) and viral cells (choice B) do not secrete antibodies as they are pathogens. Lymph cells (choice C) are a general term for various types of white blood cells, including plasma cells, but not all lymph cells secrete antibodies. Plasma cells, on the other hand, are specialized for antibody production, making choice D the correct answer.