protein synthesis begins with a process known as transcription what is produced during this process

HESI RN

Biology Test

1. Protein synthesis begins with a process known as transcription. What is produced during this process?

A. A codon
B. A DNA helix
C. A DNA strand
D. An RNA strand

Correct answer: D

Rationale: The correct answer is D: An RNA strand. During transcription, the DNA template is used to produce an RNA strand, not a codon, DNA helix, or another DNA strand. A codon is a sequence of nucleotides that specifies a particular amino acid during translation, not produced during transcription. A DNA helix refers to the double-stranded structure of DNA, which is not produced during transcription. Another DNA strand is not produced during transcription since the process involves creating an RNA copy of a specific gene.

2. What percentage of the parents' offspring is predicted to have a cleft chin if one parent carries the recessive gene for a cleft chin (c) while the other parent does not?

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

Correct answer: C

Rationale: The correct answer is C (0%). If one parent carries the recessive gene for a cleft chin while the other parent does not carry it, none of their offspring is predicted to have a cleft chin. This is because the cleft chin trait is recessive, so for an offspring to express this trait, they would need to inherit the gene from both parents. In this scenario, none of the offspring will inherit the recessive gene from both parents, so the percentage of offspring predicted to have a cleft chin is 0%. Choices A, B, and D are incorrect because in this situation, the offspring will not express the cleft chin phenotype, although they could be carriers of the recessive gene.

3. Which of the following molecules acts as the genetic code's messenger?

A. RNA
B. Proteins
C. DNA
D. Carbohydrates

Correct answer: A

Rationale: The correct answer is RNA. RNA, particularly mRNA, serves as the messenger that carries genetic information from DNA to the ribosome, where proteins are synthesized. Proteins (choice B) are not the genetic code's messenger; they are synthesized based on the information carried by RNA. DNA (choice C) stores the genetic information but does not directly act as the messenger. Carbohydrates (choice D) are not involved in transmitting genetic information.

4. Which of the following organelles is known as the cell's digestion center?

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

Correct answer: C

Rationale: The correct answer is C: Lysosomes. Lysosomes contain enzymes that break down waste materials and cellular debris within the cell, making them the cell's digestion center. Choice A, Chloroplasts, are responsible for photosynthesis. Choice B, Mitochondria, are the powerhouse of the cell, generating energy. Choice D, Ribosomes, are involved in protein synthesis. Therefore, Lysosomes are specifically known for their role in digestion within the cell.

5. What must first occur before a cell can be divided to grow, develop, and reproduce organisms?

A. RNA replication
B. DNA replication
C. Gene replication
D. Chromosome replication

Correct answer: B

Rationale: The correct answer is B: DNA replication. Before a cell can divide to grow, develop, and reproduce organisms, DNA replication must occur. This process ensures that each daughter cell receives an identical set of genetic information. Choices A, C, and D are incorrect because while RNA, genes, and chromosomes are essential components of cell division, DNA replication is the specific process that must first occur to ensure accurate transmission of genetic material.