in dna the nucleotide base adenine always binds with which of the following

HESI RN

Biology Test

1. In DNA, the nucleotide base adenine always binds with which of the following?

A. Guanine
B. Uracil
C. Thymine
D. Cytosine

Correct answer: C

Rationale: The correct answer is C: Thymine. In DNA, adenine always pairs with thymine, forming a base pair held together by hydrogen bonds. Guanine pairs with cytosine. Uracil is found in RNA, not DNA. Cytosine pairs with guanine. Therefore, option C is the correct pairing for adenine in DNA.

2. A molecule's specific heat is the amount of heat necessary to raise the temperature of 1 gram of that molecule by:

A. One degree Celsius
B. Five degrees Celsius
C. Two degrees Celsius
D. Four degrees Celsius

Correct answer: A

Rationale: The correct answer is A: 'One degree Celsius.' Specific heat is defined as the amount of heat required to raise the temperature of one gram of a substance by one degree Celsius. This property is specific to each substance and is used in various calculations involving heat and temperature changes. Choices B, C, and D are incorrect because specific heat is always measured per one degree Celsius increase in temperature for one gram of the substance, not five degrees, two degrees, or four degrees.

3. What is considered the main objective of the translation stage of protein synthesis?

A. To produce amino acids
B. To produce nucleotides
C. To produce fatty acids
D. To produce nucleic acids

Correct answer: A

Rationale: The correct answer is A: To produce amino acids. During the translation stage of protein synthesis, the mRNA is decoded to assemble a specific sequence of amino acids. These amino acids then fold into a functional protein. Choices B, C, and D are incorrect because the translation stage specifically deals with the production of amino acids, not nucleotides, fatty acids, or nucleic acids.

4. What is located on the rough endoplasmic reticulum?

A. Microvilli
B. Mitochondria
C. Lysosomes
D. Ribosomes

Correct answer: D

Rationale: The rough endoplasmic reticulum is studded with ribosomes, which are responsible for protein synthesis. Ribosomes are the correct answer because they are the organelles directly associated with the rough endoplasmic reticulum. Microvilli (choice A), mitochondria (choice B), and lysosomes (choice C) are not typically located on the rough endoplasmic reticulum. Microvilli are found on the surface of cells to increase surface area, mitochondria are the powerhouses of the cell responsible for energy production, and lysosomes are membrane-bound organelles containing digestive enzymes.

5. What is the science of biological classification commonly called?

A. Taxonomy
B. Physiology
C. Botany
D. Zoology

Correct answer: A

Rationale: Taxonomy is the science of naming, defining, and classifying groups of biological organisms based on shared characteristics. Physiology (choice B) is the study of the functions and processes of living organisms, not classification. Botany (choice C) is the study of plants, while Zoology (choice D) is the study of animals. Therefore, the correct answer is Taxonomy (choice A).