which muscle causes a joint to bend

ATI TEAS 7

ATI TEAS Practice Science Test

1. Which muscle causes a joint to bend?

A. Cardiac
B. Extension
C. Flexor
D. Smooth

Correct answer: C

Rationale: The correct answer is C: Flexor. A flexor muscle contracts to bend a joint, such as bending the elbow or knee. Flexor muscles are responsible for flexing or bending a joint, while extensor muscles are responsible for extending or straightening a joint. Choice A, Cardiac, is incorrect as cardiac muscle is found in the heart and is responsible for pumping blood. Choice B, Extension, is incorrect as extension refers to the straightening or extending movement of a joint, which is opposite to bending. Choice D, Smooth, is incorrect as smooth muscles are involuntary muscles found in organs like the intestines and blood vessels, not directly responsible for bending joints.

2. What is the main function of the small intestine?

A. To store food and break it down into smaller pieces
B. To absorb nutrients into the bloodstream
C. To produce enzymes that help digest food
D. To eliminate waste products from the body

Correct answer: B

Rationale: The small intestine is a crucial part of the digestive system responsible for absorbing nutrients into the bloodstream. This absorption primarily occurs through the villi lining the small intestine, which increases the surface area available for nutrient absorption. Nutrients like carbohydrates, proteins, fats, vitamins, and minerals are absorbed into the bloodstream to support various bodily functions such as energy production, growth, and repair. Choices A, C, and D are incorrect as they do not accurately depict the primary function of the small intestine, which is nutrient absorption.

3. What are the moon-shaped white structures at the base of fingernails called?

A. Lunulae
B. Cuticle
C. Hyponychium
D. Matrix

Correct answer: A

Rationale: The correct answer is A: Lunulae. The moon-shaped white structures at the base of fingernails are known as lunulae. They are most prominent on the thumb and are situated at the base of the nail matrix. The lunula is the visible part of the nail matrix, which is responsible for generating new nail cells. Choice B, Cuticle, is incorrect as it refers to the thin layer of skin at the base of the nail plate. Choice C, Hyponychium, is incorrect as it is the skin that lies beneath the free edge of the nail. Choice D, Matrix, is incorrect as it is the area where the nail is formed, located under the cuticle.

4. What is the process called in which a substance changes from a gas to a liquid?

A. Condensation.
B. Evaporation.
C. Sublimation.
D. Vaporization.

Correct answer: A

Rationale: Condensation is indeed the correct answer. It is the process by which a substance changes from a gas to a liquid. This occurs when the temperature of a gas decreases enough for its particles to lose energy and come together to form a liquid. On the other hand, evaporation is the process of a liquid changing to a gas. Sublimation is the direct transition of a substance from a solid to a gas without passing through the liquid phase. Vaporization, on the other hand, is the general term for the process of a liquid changing to a gas, which includes both evaporation and boiling.

5. What role does DNA play in evolution?

A. It stores genetic information that can be passed on to offspring.
B. It allows for mutations that can introduce new variations.
C. It regulates the expression of genes that influence traits.
D. All of the above

Correct answer: D

Rationale: A) DNA stores genetic information that is passed on from parents to offspring through the process of reproduction. This genetic information contains instructions for the development and functioning of an organism. It serves as the hereditary material that carries the blueprint for an organism's traits and characteristics, allowing for the transmission of genetic information from one generation to the next. B) DNA can undergo mutations, which are changes in the genetic sequence. These mutations can introduce new variations in the DNA, leading to genetic diversity within a population. These variations are essential for natural selection and adaptation to changing environments. C) DNA plays a crucial role in regulating the expression of genes. Gene expression determines which proteins are produced in an organism, influencing its traits and characteristics. By controlling gene expression, DNA contributes to the development and maintenance of an organism's traits. D) Therefore, DNA is involved in all of the above processes, making it a key factor in evolution by driving genetic variation, inheritance, and gene expression. The interplay of these functions allows for the diversity and adaptation of species over time, shaping the evolutionary process.