Science TEAS Practice Test

Correct Answer: B

Rationale: The correct answer is B: Thymine. Thymine is a nucleobase that exists in DNA, not RNA. RNA contains Uracil instead of Thymine. This is due to a different chemical structure in RNA which lacks the methyl group present in Thymine. Uracil pairs with Adenine in RNA, while Thymine pairs with Adenine in DNA. Choices A, C, and D (Uracil, Cytosine, Guanine) are all nucleobases found in RNA, making them incorrect answers.

Correct Answer: A

Rationale: The correct answer is A: Phenotype. Phenotype refers to the physical and visible expression of a genetic trait. It includes observable characteristics like eye color, height, and hair texture. This is different from genotype, which represents the genetic makeup of an organism. Allele refers to different forms of a gene, and gamete is a reproductive cell. Thus, in this context, phenotype best describes the physical manifestation of a genetic trait, making it the correct answer.

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.

Correct Answer: C

Rationale: The correct answer is C: Small intestine. This is because the small intestine is where the majority of nutrient absorption occurs in the digestive system. The small intestine is lined with villi and microvilli, which greatly increase its surface area for absorption. Digestive enzymes and bile are also released in the small intestine to further break down nutrients for absorption. The stomach mainly breaks down food, the large intestine primarily absorbs water and electrolytes, and the mouth initiates digestion through chewing and mixing food with saliva.

Correct Answer: D

Rationale: The correct answer is D because the ulna, fibula, and humerus are classified as long bones. Long bones are characterized by their elongated shape, with a shaft and two distinct ends. The ulna and humerus are long bones of the upper extremities, while the fibula is a long bone of the lower extremity. A, the sacrum, is a triangular bone at the base of the spine and is classified as a flat bone. B, the clavicle, is also a flat bone that connects the sternum to the scapula. C, the patella, is a sesamoid bone located in the knee joint and is not classified as a long bone. Therefore, the correct answer is D, as the ulna, fibula, and humerus are examples of long bones based on their structure and function.