which of the following molecules contains the code that is required for replication

HESI RN

Biology Test

1. Which of the following molecules contains the code required for replication?

A. Deoxyribonucleic acid (DNA)
B. Transfer RNA (tRNA)
C. Messenger RNA (mRNA)
D. Ribonucleic acid (RNA)

Correct answer: A

Rationale: The correct answer is A: Deoxyribonucleic acid (DNA). DNA contains the genetic information essential for replication, ensuring the accurate transmission of genetic material from one generation to the next. Choice B, Transfer RNA (tRNA), is involved in protein synthesis, not replication. Choice C, Messenger RNA (mRNA), carries genetic information from DNA to the ribosome but does not contain the code for replication. Choice D, Ribonucleic acid (RNA), is a broader category that includes both mRNA and tRNA, but the specific molecule containing the code required for replication is DNA.

2. Which of the following options correctly lists biology's hierarchical organizational system?

A. Phylum, Kingdom, Class, Family, Order, Species, Genus
B. Kingdom, Phylum, Class, Order, Family, Genus, Species
C. Genus, Order, Kingdom, Class, Phylum, Species, Family
D. Class, Phylum, Kingdom, Genus, Order, Family, Species

Correct answer: B

Rationale: The correct hierarchical organizational system in biology is Kingdom, Phylum, Class, Order, Family, Genus, and Species. This follows the mnemonic 'King Phillip Came Over For Good Soup.' Choice A is incorrect as it does not follow the correct hierarchical order. Choice C is incorrect as it starts with Genus, which is more specific and should come after Family. Choice D is incorrect as it does not follow the correct hierarchical order.

3. 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.

4. The Punnett square shows that one parent carries the recessive gene for a cleft chin (c) while the other parent does not. What percentage of the parents' offspring is predicted to have a cleft chin?

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

Correct answer: C

Rationale: The correct answer is 0%. If one parent carries the recessive gene for a cleft chin while the other parent does not, none of the offspring will express the recessive phenotype. This is because in order for a child to have a cleft chin, they would need to inherit the recessive gene from both parents. Therefore, although the offspring could be carriers of the gene, none are predicted to have a cleft chin. Choices A, B, and D are incorrect because the presence of the recessive gene in one parent and its absence in the other would not result in any offspring showing the cleft chin trait.

5. The term pleiotropy is best defined as which of the following?

A. A situation in which one gene remains unexpressed
B. One gene influencing multiple, seemingly unrelated phenotypic traits
C. Two genes affected by a single allele
D. A condition in which multiple genes are missing

Correct answer: B

Rationale: Pleiotropy is best defined as one gene influencing multiple, seemingly unrelated phenotypic traits. This phenomenon showcases the multifunctionality of genes, where a single gene can have effects on various aspects of an organism's phenotype. Choices A, C, and D do not accurately capture the concept of pleiotropy. Option A refers to gene expression, not pleiotropy. Option C describes genetic interactions but not in the context of pleiotropy. Option D talks about missing genes, which is unrelated to the definition of pleiotropy.