Identify the following types of cells that do HIV preferentially infect.

Correct Answer: B

Rationale: The correct answer is B: Helper T cells. HIV preferentially infects Helper T cells because they express the CD4 receptor, which serves as the primary binding site for the virus. Once infected, HIV impairs the Helper T cells' function, leading to immune system dysfunction. Memory cells (A), Cytotoxic T cells (C), and Natural killer cells (D) are not the primary targets of HIV infection as they do not express the CD4 receptor necessary for HIV entry and replication. Helper T cells are crucial for orchestrating immune responses, making them the primary target for HIV infection.

Correct Answer: D

Rationale: The correct answer is D because BLASTN searches nucleotide databases, not protein databases. BLASTN uses a nucleotide sequence as the query to find similar sequences in nucleotide databases. This is different from BLASTX, which searches protein databases using translated nucleotide sequences (answer A is correct). TBLASTX and TBLASTN translate the query sequence into six reading frames to search for similarities in both nucleotide and protein databases (answer C is correct). BLASTN is specifically designed for nucleotide sequence searches, making statement D incorrect.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.