which type of muscle tissue is found in the walls of blood vessels and helps regulate blood flow

ATI TEAS 7

Mometrix TEAS 7 science practice test

1. Which type of muscle tissue is found in the walls of blood vessels and helps regulate blood flow?

A. Skeletal muscle
B. Smooth muscle
C. Cardiac muscle
D. Striated muscle

Correct answer: B

Rationale: Smooth muscle is the correct answer. It is found in the walls of blood vessels and helps regulate blood flow by contracting and relaxing to adjust the diameter of the vessels. Skeletal muscle, found attached to bones, is responsible for voluntary movements and is not typically found in blood vessel walls. Cardiac muscle is specific to the heart and responsible for pumping blood, not found in blood vessel walls. Striated muscle, another term for skeletal muscle, is characterized by its striped appearance under a microscope but is not present in blood vessel walls.

2. What is the importance of RNA splicing?

A. Removes introns from the mRNA molecule
B. Adds the poly-A tail to the mRNA molecule
C. Activates the mRNA molecule for translation
D. Modifies the structure of the protein

Correct answer: A

Rationale: RNA splicing is a crucial process in gene expression where non-coding regions called introns are removed from the pre-mRNA molecule, and the remaining coding regions called exons are joined together to form the mature mRNA molecule. This process ensures that only the protein-coding sequences are retained in the mRNA for translation, allowing for the production of functional proteins. Therefore, option A is the correct answer as it accurately describes the importance of RNA splicing in generating mature mRNA molecules for protein synthesis. B) Adding the poly-A tail to the mRNA molecule is a post-transcriptional modification that occurs after RNA splicing and is not directly related to the process of removing introns. C) Activating the mRNA molecule for translation is typically achieved through the addition of a 5' cap and the poly-A tail, rather than through RNA splicing. D) Modifying the structure of the protein is not directly related to the process of RNA splicing, which primarily focuses on mRNA maturation by removing non-coding introns.

3. Which of the following glands produces growth hormone?

A. Pituitary
B. Thyroid
C. Adrenal
D. Pancreas

Correct answer: A

Rationale: The correct answer is A: Pituitary. The pituitary gland, also known as the master gland, produces growth hormone, which plays a crucial role in stimulating growth and cell reproduction. Choice B, the thyroid gland, primarily produces hormones that regulate metabolism, not growth hormone. Choice C, the adrenal glands, produce hormones like cortisol and adrenaline, but not growth hormone. Choice D, the pancreas, produces insulin and glucagon for regulating blood sugar levels, not growth hormone.

4. Rusting of iron is an example of

A. Endothermic reaction
B. Exothermic reaction
C. Single displacement reaction
D. Photochemical reaction

Correct answer: A

Rationale: The rusting of iron is an endothermic reaction. This means that it absorbs heat from its surroundings to occur. Rusting involves the slow oxidation of iron in the presence of oxygen and water. As energy is absorbed during this process, it is classified as an endothermic reaction. Choice B, an exothermic reaction, releases heat instead of absorbing it, which is not the case in rusting. Choices C and D are unrelated to the process of rusting and do not involve the absorption of heat from the surroundings.

5. According to the periodic table, which of the following elements is the least reactive?

A. Fluorine
B. Silicon
C. Neon
D. Gallium

Correct answer: C

Rationale: Neon is the least reactive among the given elements because it belongs to the noble gases group in the periodic table. Noble gases have a full valence shell of electrons, making them highly stable and least likely to react with other elements. Fluorine is the most reactive non-metal due to its high electronegativity. Silicon is a metalloid with moderate reactivity, falling between metals and nonmetals. Gallium is a metal with higher reactivity compared to Neon, but it is not as reactive as Fluorine.