Question

question 23 (2 points)
the main reason(s) for the different distributions of blood type abo alleles in the world is due to...

differential fertility
disease incidence
a and b
none of the above

question 24 (2 points)
the pathogen which targets helper t cells in order to reproduce and propagate is called...

influenza a
hiv
spanish flu
avian flu

Explanation:

Analyze ABO allele distribution factors

Using the ABO Blood Groups knowledge point
The global distribution of ABO blood group alleles is shaped by natural selection. Two major selective pressures are:

• Differential fertility: Maternal-fetal ABO incompatibility can lead to early pregnancy loss, affecting reproductive success.
• Disease incidence: Certain blood types provide resistance or susceptibility to infectious diseases (e.g., cholera, malaria, and plague), driving allele frequencies in different regions.

Thus, both factors (A and B) are responsible.

Identify the pathogen targeting helper T cells

Using the Helper T Cell Pathogens and HIV Infection knowledge points

• Human Immunodeficiency Virus (HIV) specifically binds to CD4 receptors on the surface of helper T cells.
• It uses these host cells to replicate, ultimately destroying them and compromising the immune system.
• Influenza A, Spanish flu, and Avian flu primarily target respiratory epithelial cells, not helper T cells.

Therefore, the correct pathogen is HIV.

Answer:

Question 23

• differential fertility
• disease incidence
• A and B (Correct answer)
• none of the above

Question 24

• Influenza A
• HIV (Correct answer)
• Spanish flu
• Avian flu