Award Date

5-15-2026

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Life Sciences

First Committee Member

Frank van Breukelen

Second Committee Member

Jenifer Utz

Third Committee Member

Allyson Hindle

Fourth Committee Member

Kim Metcalf

Number of Pages

90

Abstract

Most modern mammals maintain stable body temperatures (Tb) ~37ºC and high metabolic rates. Hibernators, like ground squirrels, are homeothermic during the active summer season, but are heterothermic during the hibernation season. During the hibernation season, ground squirrels follow a predictable pattern of torpor bouts interrupted by interbout arousals. Tenrecs are unusual because they are heterothermic and heterometabolic even during the active season. Previously, ground squirrel bile constituents were shown to be predictive of whether a squirrel is in the summer active or winter hibernation season. We found tenrec bile constituents were highly variable and not predictive of seasonal and metabolic state. The extreme variability of tenrec physiology suggests poor homeostatic control. We contend that tenrecs are reminiscent of ancestral placental mammals, which were likely heterothermic, heterometabolic, and not homeostatic. It seems tenrecs are so variable because they demonstrate ancestral physiology.

Human behavior is influenced by a myriad of factors including background, skill level, and motivations. Developing a curriculum is challenging because it can be difficult to engage all students in the same coursework. In laboratory courses, students need to master technical skills in addition to learning conceptual knowledge. In microbiology labs, the streak plate method of isolation is required to purify mixed cultures. We found that students were not mastering this technique well enough to identify bacteria they isolated from soil samples. Our students seem highly motivated by performance measures. Therefore, a study was conducted to determine whether adding a skills assessment over the streak plate method of isolation would lead to improved technique accuracy. Biology majors given a medium stakes skills assessment over the streak plate method of isolation obtained more well-isolated colonies at the end of the semester than biology majors in the control group. Additionally, 70% of all students purified their soil isolates well enough to obtain a gene sequence usable for identification compared to 11.5% previously. Skills assessment can be a useful tool for motivating students to master technical skills in laboratory courses.

Keywords

Anorexia; Hibernation; Homeostasis; Laboratory Technique; Skills Assessment; Thermoregulation

Disciplines

Biology | Education | Educational Assessment, Evaluation, and Research

File Format

PDF

File Size

1679 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

Rights

IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Download


Share

COinS