TEAS 7 Biology: Master Key Concepts

ATI TEAS 7

Biology

1. Molecular clocks utilize the accumulation of mutations in DNA sequences to estimate the evolutionary divergence time between species. This method relies on the assumption that:

A. The rate of mutation is constant across all genes and all species.
B. Species with more morphological similarities diverged more recently.
C. Mutations are always beneficial and contribute to increased fitness.
D. The fossil record provides the most accurate estimates of evolutionary relationships.

Correct answer: A

Rationale: Rationale: A molecular clock is a method used to estimate the time of divergence between species by measuring the accumulation of mutations in DNA sequences. This method relies on the assumption that mutations occur at a relatively constant rate over time. If the rate of mutation were not constant, it would be challenging to accurately estimate the evolutionary divergence time between species. Therefore, option A is the most appropriate choice as it aligns with the fundamental principle underlying the molecular clock hypothesis. Option B is incorrect because the assumption that species with more morphological similarities diverged more recently does not directly relate to the concept of molecular clocks and the accumulation of mutations in DNA sequences. Option C is incorrect because mutations are not always beneficial and do not always contribute to increased fitness. Mutations can be neutral or deleterious as well, and their accumulation is what is used to estimate evolutionary di

2. Entropy (S) is a thermodynamic property related to the system's disorder. According to the second law of thermodynamics, in a spontaneous process:

A. The total entropy of the system and surroundings increases.
B. The total entropy of the system and surroundings decreases.
C. The total entropy of the system remains constant.
D. The total entropy of the surroundings increases, while the system's entropy decreases.

Correct answer: A

Rationale: Entropy is a measure of a system's disorder or randomness. According to the second law of thermodynamics, in a spontaneous process, the total entropy of the system and surroundings increases, leading to a higher level of disorder or randomness. This increase in total entropy is consistent with the idea that systems tend towards higher entropy states over time. Therefore, option A is correct because it aligns with the principle that the total entropy of a closed system, including both the system and its surroundings, will increase in a spontaneous process.

3. As a manager, she focuses her energy on both the quality of services rendered to the patients

A. Country club management
B. Organization man management
C. Team management
D. Authority-obedience management

Correct answer: B

Rationale: The correct answer is 'B: Organization man management.' This type of management focuses on maintaining the efficiency and structure of an organization. In this scenario, the manager's emphasis on the quality of services aligns with the principles of organization man management, which prioritizes the coordination of tasks and resources to achieve optimal results within the organization. This contrasts with 'Country club management,' which emphasizes employee satisfaction over task accomplishment; 'Team management,' which focuses on collaboration and teamwork; and 'Authority-obedience management,' which centers on strict hierarchical control. Therefore, the most appropriate choice is 'B: Organization man management.'

4. 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.

5. Lymph nodes, found along lymphatic vessels, are important for:

A. Storing blood
B. Producing antibodies
C. Filtering lymph and trapping harmful substances
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' Lymph nodes are important for various functions in the immune system. They filter lymph, trapping harmful substances like bacteria and viruses, which helps in preventing infections. Lymph nodes also play a crucial role in producing antibodies, which are essential for fighting off pathogens. Additionally, lymph nodes do not store blood; that is the function of the spleen. Therefore, the correct answer is D because lymph nodes perform all the mentioned functions in supporting the body's immune response.