which of the following distinguishes the isotopes of an element

ATI TEAS 7

TEAS 7 Science Practice Test

1. Which of the following distinguishes the isotopes of an element?

A. Isotopes are atoms of the same element that have different ionic charges.
B. Isotopes are atoms of elements within the same group on the periodic table.
C. Isotopes are atoms of the same element that have different numbers of neutrons.
D. Isotopes are atoms of the same element with different electron configurations.

Correct answer: C

Rationale: Isotopes are defined as atoms of the same element that have the same number of protons in their nucleus but different numbers of neutrons. This leads to variations in atomic mass for isotopes of an element. The different number of neutrons in isotopes results in differences in their atomic mass and properties while still belonging to the same element. Choice A is incorrect because isotopes do not have different ionic charges, they have the same chemical properties. Choice B is incorrect because isotopes are not atoms of elements within the same group on the periodic table; they are variants of the same element. Choice D is incorrect because isotopes of an element have the same electron configuration, differing only in the number of neutrons in the nucleus.

2. Ectopic pregnancy is a serious condition that occurs when a fertilized egg implants outside the uterus. What is the most common location for an ectopic pregnancy?

A. Ovary
B. Fallopian tube
C. Cervix
D. Vagina

Correct answer: B

Rationale: The most common location for an ectopic pregnancy is the fallopian tube. This occurs when the fertilized egg implants and grows outside the uterus, typically in the fallopian tube. Ectopic pregnancies in other locations such as the ovary, cervix, or vagina are much rarer. The fallopian tube is the correct answer because it is the site where the fertilized egg may get stuck during its journey to the uterus, leading to implantation and growth outside the uterus. The ovary is not a common site for ectopic pregnancy, and implantation there can be life-threatening due to the risk of severe bleeding. The cervix and vagina are not typical sites for implantation of a fertilized egg, making them less likely locations for an ectopic pregnancy.

3. What is the process in which RNA polymerase copies DNA into RNA, with DNA unwinding and serving as a template while RNA is assembled?

A. Replication
B. Transcription
C. Translation
D. Duplication

Correct answer: B

Rationale: The correct answer is B: Transcription. Transcription is the process where RNA polymerase reads the DNA template strand and synthesizes RNA, following the base-pairing rules. During transcription, DNA unwinds and serves as a template for the assembly of complementary RNA molecules. Replication (Choice A) is the process of making an identical copy of DNA, not RNA from DNA. Translation (Choice C) is the process of synthesizing proteins from mRNA. Duplication (Choice D) is a general term and does not specifically refer to the process described in the question.

4. What is the primary function of the large intestine?

A. To digest food
B. To absorb water and form feces
C. To absorb proteins
D. To regulate blood pressure

Correct answer: B

Rationale: The correct answer is B. The primary function of the large intestine is to absorb water from digested food and form feces for elimination. It does not primarily digest food, absorb proteins, or regulate blood pressure. Choice A is incorrect because the large intestine does not digest food but rather absorbs nutrients and water. Choice C is incorrect as the absorption of proteins primarily occurs in the small intestine. Choice D is incorrect as the regulation of blood pressure is not a primary function of the large intestine.

5. Which of the following nerves has the longest axon in the human body?

A. Dorsal root ganglion
B. Laryngeal nerve
C. Sciatic nerve
D. None of the above

Correct answer: C

Rationale: The sciatic nerve contains the longest axon in the human body, extending from the lower back down the leg. This nerve is responsible for innervating the muscles of the lower limb. The dorsal root ganglion and laryngeal nerve do not possess axons as long as the sciatic nerve, making them incorrect choices. Therefore, the correct answer is C, the sciatic nerve.