what is the role of transfer rna trna in protein synthesis

ATI TEAS 7

ati teas 7 science

1. What is the role of transfer RNA (tRNA) in protein synthesis?

A. Transcribes DNA into mRNA
B. Decodes the genetic code on mRNA
C. Carries specific amino acids to the ribosomes
D. Modifies the structure of proteins

Correct answer: C

Rationale: A) Transcribes DNA into mRNA: This is the function of RNA polymerase, not transfer RNA (tRNA). tRNA is involved in protein synthesis, not transcription. B) Decodes the genetic code on mRNA: This is the function of tRNA during translation. tRNA molecules carry specific amino acids and recognize the codons on mRNA, ensuring the correct amino acid is added to the growing polypeptide chain. C) Carries specific amino acids to the ribosomes: This is the primary role of tRNA in protein synthesis. Each tRNA molecule is specific for a particular amino acid and carries it to the ribosome, where it is added to the growing protein chain. D) Modifies the structure of proteins: This is not a function of tRNA. Protein modification can occur after translation is complete and involves other cellular processes and molecules.

2. Which type of cell division is responsible for sexual reproduction?

A. Mitosis
B. Meiosis
C. Amitosis
D. Cytokinesis

Correct answer: B

Rationale: Meiosis is the type of cell division responsible for sexual reproduction. During meiosis, a single cell undergoes two rounds of division to produce four daughter cells, each with half the number of chromosomes as the parent cell. This reduction in chromosome number is essential for sexual reproduction as it ensures that when two gametes (sperm and egg) combine during fertilization, the resulting zygote will have the correct number of chromosomes. Mitosis, on the other hand, is a type of cell division that produces two daughter cells with the same number of chromosomes as the parent cell and is involved in growth, repair, and asexual reproduction. Amitosis is a rare form of cell division that does not involve the typical processes of mitosis or meiosis. Cytokinesis is the process of dividing the cytoplasm of a cell after mitosis or meiosis.

3. Which statement correctly matches the valve with its function in the heart?

A. The aortic valve allows oxygenated blood to flow from the left ventricle to the rest of the body.
B. The mitral valve opens to allow blood flow from the left atrium to the left ventricle.
C. The pulmonic valve allows deoxygenated blood to flow from the right ventricle to the pulmonary artery.
D. The tricuspid valve allows deoxygenated blood to flow from the right atrium to the right ventricle.

Correct answer: A

Rationale: The correct answer is A. The aortic valve allows oxygenated blood to flow from the left ventricle to the rest of the body. When the left ventricle contracts, the aortic valve opens to allow blood to be pumped into the aorta, the body's main artery that carries oxygen-rich blood to various parts of the body. Choices B, C, and D are incorrect because they do not match the described functions of the mitral, pulmonic, and tricuspid valves, respectively. The mitral valve controls the flow of blood between the left atrium and left ventricle, the pulmonic valve regulates the flow of blood from the right ventricle to the pulmonary artery, and the tricuspid valve manages the blood flow between the right atrium and right ventricle.

4. Which cavity contains all of the frontal cavities? Choose only ONE best answer.

A. Dorsal
B. Thoracic
C. Abdominopelvic
D. Ventral

Correct answer: D

Rationale: The correct answer is D: Ventral. The ventral cavity includes both the thoracic and abdominopelvic cavities. The frontal cavities are part of the ventral cavity, which is located towards the front of the body, while the dorsal cavity is towards the back. The dorsal cavity contains the cranial and vertebral cavities, not the frontal cavities. The thoracic cavity is part of the ventral cavity but does not encompass all the frontal cavities. The abdominopelvic cavity is also part of the ventral cavity, but it does not include all of the frontal cavities. Therefore, the ventral cavity is the correct choice as it encompasses all the frontal cavities.

5. What term describes the functional unit of a skeletal muscle responsible for muscle contraction?

A. Myofibril
B. Sarcomere
C. Tendon
D. Myoglobin

Correct answer: B

Rationale: The correct answer is B, 'Sarcomere.' The sarcomere is indeed the functional unit of a skeletal muscle responsible for muscle contraction. It is composed of actin and myosin filaments that interact to generate muscle contraction. Choice A, 'Myofibril,' is incorrect as myofibrils are composed of sarcomeres, not the functional units themselves. Choice C, 'Tendon,' is incorrect as tendons connect muscles to bones and do not directly participate in muscle contraction. Choice D, 'Myoglobin,' is incorrect as myoglobin is a protein that stores oxygen in muscle cells and is not directly involved in muscle contraction.