ATI TEAS 7
TEAS 7 practice test science
1. Which of these pairs represents an example of convergent evolution?
- A. Humans and chimpanzees
- B. Bats and birds
- C. Dolphins and sharks
- D. Snakes and earthworms
Correct answer: B
Rationale: Convergent evolution refers to the process by which different species independently evolve similar traits or characteristics due to similar environmental pressures. In the case of bats and birds, both have evolved wings for flight despite not sharing a recent common ancestor with wings. Bats are mammals, while birds are avians, yet they both have wings adapted for flight, which is a classic example of convergent evolution. A) Humans and chimpanzees share a common ancestor and have not independently evolved similar traits. C) Dolphins and sharks are not closely related, and their similarities are due to adaptations to their aquatic environment rather than convergent evolution. D) Snakes and earthworms belong to different classes (reptiles and annelids, respectively) and do not share recent common ancestors, making their similarities not a result of convergent evolution.
2. The critical angle is defined as the minimum angle of incidence in a denser medium for which light undergoes:
- A. Total internal reflection
- B. Continued refraction
- C. Specular reflection
- D. Increased dispersion
Correct answer: A
Rationale: The critical angle is the minimum angle of incidence in a denser medium at which light undergoes total internal reflection instead of refraction. This phenomenon occurs when light travels from a denser medium to a less dense medium, and the angle of incidence is greater than the critical angle. Total internal reflection is a crucial concept in optics and is utilized in various applications such as fiber optics and prisms. Choice B, 'Continued refraction,' is incorrect as the critical angle specifically marks the point at which total internal reflection occurs, not continued refraction. Choice C, 'Specular reflection,' does not accurately describe the phenomenon associated with the critical angle. Choice D, 'Increased dispersion,' is unrelated to the concept of the critical angle and does not describe the behavior of light at this specific point.
3. What is the common name for the compound CH₃COOH?
- A. Acetic acid
- B. Formic acid
- C. Butyric acid
- D. Propionic acid
Correct answer: A
Rationale: The compound CH₃COOH is commonly known as acetic acid. Acetic acid is a clear, colorless liquid with a sour taste and a pungent smell. It is a weak acid found in vinegar and is used in the production of various chemicals. Formic acid, butyric acid, and propionic acid are different organic acids with distinct chemical structures and properties, but they are not the common name for the compound CH₃COOH.
4. Which structure connects the two hemispheres of the brain, allowing communication and coordination between them?
- A. Corpus callosum
- B. Thalamus
- C. Hypothalamus
- D. Medulla oblongata
Correct answer: A
Rationale: The correct answer is the corpus callosum. It is a thick band of nerve fibers that connects the two hemispheres of the brain, facilitating communication and coordination between them. The thalamus acts as a relay station for sensory information, the hypothalamus regulates basic functions like hunger and thirst, and the medulla oblongata controls vital functions such as breathing and heart rate. Therefore, choices B, C, and D are incorrect as they do not specifically connect the two hemispheres of the brain as the corpus callosum does.
5. Which of the following units is used to express concentration as a mass of solute per unit volume of solution?
- A. Molality (m)
- B. Molarity (M)
- C. Weight percent (%)
- D. Parts per million (ppm)
Correct answer: A
Rationale: Molality (m) is the unit used to express concentration as a mass of solute per unit volume of solution. It is calculated by dividing the mass of solute in grams by the mass of the solvent in kilograms. Molality is preferred over molarity when there are large temperature variations as it is temperature-independent, making it a more accurate measure of concentration. Molarity (B) is the unit used to express concentration as moles of solute per liter of solution, weight percent (C) is the mass of solute per 100 parts of the total mass of the solution, and parts per million (D) is used to express very small concentrations where 1 ppm is equivalent to 1 mg of solute per liter of solution.
Similar Questions
Access More Features
ATI TEAS Premium Plus
$149.99/ 90 days
- Actual ATI TEAS 7 Questions
- 3,000 questions with answers
- 90 days access
ATI TEAS Basic
$99/ 30 days
- 3,000 Questions with answers
- 30 days access