A cross is made between an Hfr that is met+ thi+ pur+ and an F-that is met- thi- pur-. Interrupted mating studies show that met+ enters the recipient last, so met+ recombinants are selected on a medium containing supplements that satisfy only the pur and thi requirements.  These recombinants are tested for the presence of the thi+ and pur+ alleles. The following numbers of individuals are found for each genotype:

A) Gene Order	I	Thi Pur  Met
	II	Pur  Met  Thi
	III	Pur   Thi  Met
B) Distance between Pur and Thi	IV	15.4 map unit
	V	1.8 map unit

What is the following correct combination?

#Question id: 4997

#Unit 11. Evolution and Behavior

If one organ is an exaptation of another organ, then what must be true of these two organs?

#Question id: 4998

#Unit 11. Evolution and Behavior

Many species of snakes lay eggs, but in the forests of northern Minnesota where growing seasons are short, only live-bearing snake species are present. This trend toward species that perform live birth is an example of

#Question id: 4999

#Unit 11. Evolution and Behavior

In the 5—7 million years that the hominid lineage has been diverging from its common ancestor with the great apes, dozens of hominid species have arisen, often with several species coexisting in time and space. As recently as 30,000 years ago, Homo sapiens coexisted with Homo neanderthalensis. Both species had large brains and advanced intellects. The fact that these traits were common to both species is most easily explained by which of the following?

#Question id: 5000

#Unit 11. Evolution and Behavior

The existence of evolutionary trends, such as increasing body sizes among horse species, is evidence that

#Question id: 5001

#Unit 11. Evolution and Behavior

Fossil evidence indicates that several kinds of flightless dinosaurs possessed feathers. If some of these feather-bearing dinosaurs incubated clutches of eggs in carefully constructed nests, this might be evidence supporting the claim that

#Question id: 5002

#Unit 11. Evolution and Behavior

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?