Table 271 Proposed Number of Hox Genes in Various Extant and and Extinct

question 23

Multiple Choice

Table 27.1. Proposed Number of Hox Genes in Various Extant and Extinct Animals
-All things being equal, which of these is the most parsimonious explanation for the change in the number of Hox genes from the last common ancestor of insects and vertebrates to ancestral vertebrates, as shown in Table 27.1?

• A) The occurrence of seven independent duplications of individual Hox genes.
• B) The occurrence of two distinct duplications of the entire seven-gene cluster, followed by the loss of one cluster.
• C) The occurrence of a single duplication of the entire seven-gene cluster.

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Definitions:

Cyclic Electron Pathway

A photosynthetic process in plants and some bacteria where electrons are recycled allowing for the production of ATP without the production of NADPH or oxygen.

Photosynthetic Pigment

Molecules that absorb specific wavelengths of sunlight and use this energy to carry out photosynthesis in plants and algae.

Visible Wavelengths

The portion of the electromagnetic spectrum that is visible to the human eye, ranging approximately from 380 to 750 nanometers.

Experiential Learning

A learning process through which students develop knowledge, skills, and values from direct experiences outside a traditional academic setting.