protein synthesis begins with a process known as transcription where does this process occur

HESI RN

Biology Practice Test

1. Protein synthesis begins with a process known as transcription. Where does this process occur?

A. In the cytoplasm
B. In the nuclear envelope
C. In the ribosome unit
D. In the nucleus

Correct answer: D

Rationale: The correct answer is D: In the nucleus. Transcription, the initial step of protein synthesis, takes place in the nucleus where DNA is transcribed into mRNA. This mRNA then leaves the nucleus and enters the cytoplasm where translation occurs on the ribosomes. Choices A, B, and C are incorrect because transcription specifically occurs in the nucleus, not in the cytoplasm, nuclear envelope, or ribosome unit.

2. What is the smallest and most basic unit of matter?

A. Micromolecule
B. Atom
C. Organelle
D. Molecule

Correct answer: B

Rationale: The correct answer is B, Atom. An atom is the smallest unit of matter that retains the properties of an element. Choice A, Micromolecule, is incorrect because molecules are composed of atoms bonded together, making them larger than individual atoms. Choice C, Organelle, is incorrect as organelles are structures within cells, not the basic unit of matter. Choice D, Molecule, is incorrect as molecules are made up of atoms bonded together, so they are not the smallest unit of matter.

3. Proteins are polymers of 20 molecules called:

A. Amino acids
B. Phospholipids
C. Carbohydrates
D. Fatty acids

Correct answer: A

Rationale: Proteins are indeed polymers made up of amino acids. Amino acids are the building blocks of proteins, where each protein has a unique sequence of amino acids that determines its structure and function. Phospholipids, carbohydrates, and fatty acids are not molecules that make up proteins. Phospholipids are the main components of cell membranes, carbohydrates are sugars used for energy and structural purposes, and fatty acids are building blocks of lipids.

4. The cellular membrane contributes to all except which of the following?

A. Cell energy production
B. Cell permeability
C. Cell communication
D. Cell protection

Correct answer: A

Rationale: The cellular membrane is involved in regulating cell permeability, communication, and protection. However, it is not directly involved in energy production. Choice A is the correct answer because the cellular membrane does not produce energy; instead, it regulates the passage of molecules in and out of the cell. Choices B, C, and D are incorrect because the cell membrane plays key roles in controlling what enters and exits the cell, facilitating communication between cells, and providing structural support and protection to the cell.

5. What percentage of the offspring of the parents is predicted to have a cleft chin?

A. 25%
B. 50%
C. 0%
D. 75%

Correct answer: A

Rationale: When one parent carries the recessive gene for a cleft chin and the other does not, there is a 25% chance of the offspring inheriting the cleft chin. This is due to the fact that the trait follows a simple Mendelian inheritance pattern, where the offspring would need to inherit the recessive gene from both parents to express the trait. Therefore, 25% of the offspring are predicted to have a cleft chin. Choices B, C, and D are incorrect because the likelihood of inheriting a cleft chin in this specific scenario is 25%, not 50%, 0%, or 75%.