TEAS 7 Biology: Master Key Concepts

ATI TEAS 7

Biology

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 bas(a) Carries amino acids to the ribosomes: This is the function of transfer RNA (tRNA), not ribosomal RNA. (b) Reads the genetic code on mRNA: This is the function of the ribosomes as a whole, not just the ribosomal RNA. (d) Controls the rate of protein synthesis: This is a more complex process involving various factors, not solely ribosomal RNA. ? ed on the mRNA
D. Modifies the structure of proteins

Correct answer: C

Rationale: 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. What is the stage of mitosis during which the nuclear envelope reforms?

A. Prophase
B. Metaphase
C. Telophase
D. Cytokinesis

Correct answer: C

Rationale: Rationale: - Prophase is the stage of mitosis where the nuclear envelope breaks down, allowing the chromosomes to condense and become visible. - Metaphase is the stage where the chromosomes line up along the metaphase plate in the middle of the cell. - Telophase is the stage where the nuclear envelope reforms around the separated sister chromatids at opposite poles of the cell. - Cytokinesis is the final stage of cell division where the cytoplasm divides to form two daughter cells, but it is not directly related to the reformation of the nuclear envelope.

3. How does the stability of an atom's nucleus influence its radioactive decay?

A. Stable nuclei never undergo radioactive decay.
B. Unstable nuclei are more likely to decay through various processes.
C. Decay releases energy, making stable nuclei more prone to it.
D. The element's position on the periodic table determines its decay rate.

Correct answer: B

Rationale: Unstable nuclei are more likely to decay through various processes. The stability of an atom's nucleus is a key factor in determining whether it will undergo radioactive decay. Unstable nuclei have an excess of either protons or neutrons, leading to an imbalance in the nucleus. To achieve a more stable configuration, these nuclei will undergo radioactive decay by emitting particles or energy. Stable nuclei, on the other hand, are less likely to undergo radioactive decay as they have a balanced number of protons and neutrons.

4. Which structure, located between the pons and the spinal cord, plays a crucial role in coordinating movements, maintaining balance, and posture?

A. Thalamus
B. Medulla oblongata
C. Cerebellum
D. Hypothalamus

Correct answer: c

Rationale: The correct answer is C: Cerebellum. The cerebellum is the structure located between the pons and the spinal cord that plays a crucial role in coordinating movements, maintaining balance, and posture. It receives information from sensory systems and integrates this input to fine-tune motor activity. The thalamus (A) is a relay station for sensory information, the medulla oblongata (B) is involved in vital functions like heartbeat and breathing, and the hypothalamus (D) regulates various metabolic processes and homeostasis. Therefore, the cerebellum is the most appropriate choice for a structure responsible for movement coordination and balance.

5. Fingernails and toenails are made primarily of:

A. Collagen (Collagen is found in the dermis)
B. Keratin
C. Melanin (Melanin provides pigment, not structure)
D. Sebum (Sebum is an oily substance)

Correct answer: B

Rationale: The correct answer is B: Keratin. Fingernails and toenails are primarily made of a tough protein called keratin. Keratin is a fibrous structural protein that also makes up hair and the outer layer of skin. Collagen, as mentioned in option A, is found in the dermis of the skin and is responsible for providing strength and elasticity to the skin. Melanin, as in option C, is a pigment that gives color to the skin, hair, and eyes, but it does not contribute to the structure of nails. Sebum, as in option D, is an oily substance produced by the sebaceous glands in the skin to moisturize and protect the skin, but it is not a component of nails.