In Comparing the Genomes of Humans and Those of Other

question 40

Multiple Choice

In comparing the genomes of humans and those of other higher primates, it is seen that humans have a large metacentric pair we call chromosome 2 among our 46 chromosomes, whereas the other primates of this group have 48 chromosomes and any pair like the human chromosome 2 pair is not present; instead, the primate groups each have two pairs of midsize acrocentric chromosomes. What is the most likely explanation?

• A) The ancestral organism had 48 chromosomes and at some point a centric fusion event occurred and provided some selective advantage.
• B) The ancestral organism had 46 chromosomes, but primates evolved when one of the pairs broke in half.
• C) At some point in evolution, human ancestors and primate ancestors were able to mate and produce fertile offspring, making a new species.
• D) Chromosome breakage results in additional centromeres being made in order for meiosis to proceed successfully.
• E) Transposable elements transferred significantly large segments of the chromosomes to new locations.

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Definitions:

Differential Carrier

The housing that encloses the differential assembly in a vehicle, supporting the gears that allow the wheels to rotate at different speeds.

Backlash

The play or slop between mating mechanical parts, such as gears, which is the result of gaps between parts.

Meshing Gears

The process where the teeth of two or more gears come into contact with each other in order to transmit power from one shaft to another.

Sliding Action

The movement or operation of a mechanism that involves two or more surfaces moving over each other with minimal resistance.