TEAS Practice Test Science

Correct Answer: A

Rationale: The correct answer is A: Helicase. Helicase is responsible for unwinding the double-stranded DNA during replication by breaking the hydrogen bonds between the base pairs. This allows the DNA strands to separate and serve as templates for the synthesis of new DNA strands by DNA polymerase. Ligase is responsible for joining the DNA fragments together, nuclease is involved in DNA repair by cutting out damaged DNA, and polymerase is responsible for synthesizing new DNA strands based on the template strands. Therefore, only helicase directly unwinds the double-stranded DNA during replication.

Correct Answer: D

Rationale: When blood sugar drops, the body needs to increase glucose levels. The correct answer, D, is that the pancreas releases glucagon. Glucagon signals the liver to break down stored glycogen into glucose, raising blood sugar levels. This is a crucial mechanism to maintain blood glucose homeostasis. Other choices (A, B, C) are incorrect as they do not address the specific response needed to increase blood sugar levels when it drops.

Correct Answer: A

Rationale: The correct answer is A: Femur. Long bones are characterized by their elongated shape, with the length exceeding the width. The femur, as the thigh bone, perfectly fits this description. It serves as a major weight-bearing bone and plays a crucial role in movement and support. Ribs and cranial bones (Choice B) belong to the category of flat bones. Sesamoid bones (Choice C) are small bones embedded within tendons. Vertebrae and hip bones (Choice D) are classified as irregular bones due to their complex shapes and structures.

Correct Answer: B

Rationale: The correct answer is B: Liver. The liver produces bile, a greenish-yellow fluid that aids in digestion by breaking down fats. The pancreas (choice A) produces digestive enzymes, not bile. The gallbladder (choice C) stores and concentrates bile produced by the liver, but it does not produce bile itself. The stomach (choice D) produces gastric juices to break down food, but it does not produce bile. Therefore, the liver is the organ responsible for producing bile to aid in digestion.

Correct Answer: B

Rationale: Sure, here's the step-by-step rationale for why choice B is the correct answer: 1. Qualitative research is subjective. 2. Scientific arguments should rely on objective, quantitative data. 3. Extensive use of qualitative research weakens objectivity. 4. Objective data strengthens scientific arguments. Summary of other choices: A: Lack of bias strengthens a scientific argument by ensuring objectivity. C: Reproducibility strengthens a scientific argument by validating results. D: Standing the test of time strengthens a scientific argument by showing consistency.