Suppose Three Sibling Species of Frogs Have the Following DNA

question 76

Multiple Choice

Suppose three sibling species of frogs have the following DNA sequences at a portion of a gene: Species 1: AGTCTAGATCGCGGTCG
Species 2: AGTCGATCGCGGACG
Species 3: TGTCTAGATCACGGTCG
Recall that the observed number of mutations can differ from the total number of actual substitutions that occurred in pairwise sequence comparisons.Which modification would align the three sequences so they could be used to make comparisons?

• A) Add a gap representing one nucleotide to Species 3 at the first nucleotide position.
• B) Add a gap representing one nucleotide to Species 2 at the fifth nucleotide position.
• C) Add a gap representing two nucleotides to Species 2 at the fifth nucleotide position.
• D) Add a gap representing two nucleotides to Species 2 at the sixteenth nucleotide position.
• E) None; no modification is needed.

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Definitions:

Astrocytes

Type of glial cell in the brain and spinal cord that performs multiple supportive functions for neurons, including maintaining the blood-brain barrier and regulating neurotransmitter levels.

Microglia

Specialized type of glial cell that acts as the main form of active immune defense in the central nervous system.

Ependymal Cells

Glial cells that line the ventricles in the brain and the central canal of the spinal cord, involved in the production and regulation of cerebrospinal fluid.

Oligodendrocytes

Glial cells in the central nervous system that produce myelin, a substance that insulates nerve fibers to increase the speed at which impulses are conducted.