Question

how does the sickle cell trait provide an advantage in malaria-endemic regions?
a. it causes a more severe form of malaria
b. it increases susceptibility to malaria
c. it hinders the malaria parasite’s ability to thrive in red blood cells
d. it eliminates the malaria parasite from the environment

which mutation occurs when the insertion or deletion of nucleotides alters the reading frame of the genetic code?
a. substitution mutation
b. point mutation
c. frameshift mutation
d. silent mutation

which type of mutation results in the addition of one or more base pairs into the dna sequence?
a. insertion mutation
b. substitution mutation
c. deletion mutation
d. silent mutation

Explanation:

First Question:

• Option a: Sickle cell trait does not cause more severe malaria; instead, it helps against it. Eliminate a.
• Option b: It does not increase susceptibility; in fact, it reduces the risk of severe malaria. Eliminate b.
• Option c: The sickle - shaped red blood cells hinder the malaria parasite (Plasmodium) from thriving, as the parasite has difficulty surviving in these abnormal cells. This is the correct mechanism.
• Option d: The sickle cell trait does not eliminate the malaria parasite from the environment; it affects the parasite's ability to infect red blood cells in the body. Eliminate d.

• Option a: Substitution mutation is the replacement of one nucleotide with another, and it does not change the reading frame. Eliminate a.
• Option b: Point mutation is a general term for a mutation affecting a single nucleotide, and not all point mutations change the reading frame (e.g., substitution is a point mutation but does not change the frame). Eliminate b.
• Option c: Frameshift mutation occurs when insertions or deletions of nucleotides (not in multiples of three) change the reading frame of the genetic code, as the way codons are read is shifted. This matches the description.
• Option d: Silent mutation is a type of substitution mutation where the amino acid sequence is not changed, and it does not involve a change in the reading frame. Eliminate d.

• Option a: Insertion mutation is defined as the addition of one or more base pairs into the DNA sequence. This matches the description in the question.
• Option b: Substitution mutation is the replacement of one nucleotide with another, not an addition. Eliminate b.
• Option c: Deletion mutation is the removal of one or more base pairs, not an addition. Eliminate c.
• Option d: Silent mutation is a type of substitution mutation that does not change the amino acid sequence, and it is not related to the addition of base pairs. Eliminate d.

Answer:

c. It hinders the malaria parasite’s ability to thrive in red blood cells

Second Question: