The Following Questions Refer to the Description Below

question 35

Multiple Choice

The following questions refer to the description below.
All animals with eyes or eyespots that have been studied so far share a gene in common. When mutated, the gene Pax-6 causes lack of eyes in fruit flies, tiny eyes in mice, and missing irises (and other eye parts) in humans. The sequence of Pax-6 in humans and mice is identical. There are so few sequence differences with fruit fly Pax-6 that the human/mouse version can cause eye formation in eyeless fruit flies, even though vertebrates and invertebrates last shared a common ancestor more than 500 million years ago.
-The appearance of Pax-6 in all animals with eyes can be explained in multiple ways. Based on the information above, which explanation is most likely?

• A)Pax-6 in all of these animals is not homologous; it arose independently in many different animal phyla due to intense selective pressure favoring vision.
• B)The Pax-6 gene is really not "one" gene. It is many different genes that, over evolutionary time and due to convergence, have come to have a similar nucleotide sequence and function.
• C)The Pax-6 gene was an innovation of an ancestral animal of the early Cambrian. Animals with eyes or eyespots are descendants of this ancestor.
• D)The perfectly designed Pax-6 gene appeared instantaneously in all animals created to have eyes or eyespots.

---

Definitions:

Committed Fixed Costs

Expenses that a company has committed to pay over a period, which do not vary with the level of production or sales.

Depreciation

An accounting method of allocating the cost of a tangible or physical asset over its useful life or life expectancy.

Variable Cost

Expenses that change in proportion to the amount of goods produced or the volume of sales.

Unit Basis

A method or metric used to measure, allocate, or assess something on a per-unit basis, often related to pricing or cost calculations.