A researcher is setting up an experiment to measure basal metabolic rate in prairie voles
(Microtus ochrogaster“a small rodent). Which of the following would be the best set of
conditions for the voles immediately before and during the measurement?
A) House the animals in a cage with plenty of food and water to avoid stress; conduct
measurements in a warmer room than the room where housed.
B) House the animals in a cage with plenty of food and water to avoid stress; conduct
measurements in a room the same temperature as the room where housed.
C) House the animals in a cage with no food for a few hours before measurement;
conduct measurements in a colder room than the room where housed, and exercise the
voles.
D) House the animals in a cage with no food for a few hours before measurement;
conduct measurements in a room the same temperature as the room where housed.
Use the following information to answer the question(s) below.
Trichoplax adhaerens (Tp) is the only living species in the phylum Placozoa.
Individuals are about 1 mm wide and only 27 μm high, are irregularly shaped, and
consist of a total of about 2000 cells, which are diploid (2n = 12). There are four types
of cells, none of which are nerve or muscle cells, and none of which have cell walls.
They move using cilia, and any “edge” can lead. Tp feeds on marine microbes, mostly
unicellular green algae, by crawling atop the algae and trapping it between its ventral
surface and the substrate. Enzymes are then secreted onto the algae, and the resulting
nutrients are absorbed. Tp sperm cells have never been observed, nor have embryos
past the 64-cell (blastula) stage.