Some college campuses have started using "puppy therapy" to help reduce stress among students according to a USA Today article. Suppose you design an experiment to test the hypothesis that puppy therapy is an effective stress reducer for students, within the context of a 6-section introductory biology course at your school. Each section has 12 students. Students in three of the sections get to play together with a pack of therapy dogs for 15 minutes at the beginning of the section recitation (or "lab") meeting. The other three sections simply observe 15 minutes of quiet free time instead. Students rate their stress levels immediately after the 15-minute period. Then you measure the percentage of students that report being 'very stressed out" for each section, and you compare the average percentage between sections that played with puppies and those that didn't.

In your puppy therapy experiment, what is the experimental unit?

a. A single student

b. A section in the course

c. The entire course

A puppy presents to your clinic for surgery because he has an intussusception. What happened to the puppy?

How many characters are there in the short story "Puppy"?

Some college campuses have started using "puppy therapy" to help reduce stress among students according to a USA Today article. Suppose you design an experiment to test the hypothesis that puppy therapy is an effective stress reducer for students, within the context of a 6-section introductory biology course at your school. Each section has 12 students. Students in three of the sections get to play together with a pack of therapy dogs for 15 minutes at the beginning of the section recitation (or "lab") meeting. The other three sections simply observe 15 minutes of quiet free time instead. Students rate their stress levels immediately after the 15-minute period. Then you measure the percentage of students that report being 'very stressed out" for each section, and you compare the average percentage between sections that played with puppies and those that didn't.

Which of the following could help improve the scope of inference for your results?

a. Conducting the experiment multiple times during the semester, and not just a single week.

b. Assigning sections to be in either the experimental or control group based on how easygoing the TA is for each section.

c. Increasing replication by having 5 sections in the experimental group and one section in the control group.

which of the following statements about good experiments is true

Explain why water is essential for the light reactions.

What are lipid-based hormones called? A. steroid hormones, B. hypothalamic hormones, C. amino-acid hormones, D. glucagon.

Yeast have mitochondria and can perform cellular respiration. What would you expect to be consumed and produced during the process of cellular respiration in yeast?

Round off the following quantities to the number of significant figures indicated in parentheses:

(a) 35,670.06 m (4, 6)

(b) 68.507 g (2, 3)

( c) 4.995 X 10$^{3}$ cm (3)

(d) 2.309 85 X 10$^{-4}$ kg (5)

What dramatically changes when starfish are removed from the stimulated ecosystem?

(a) Only minor changes occur in the ecosystem

(b) Nori Seaweed and Black pine populations increase in size

(c) the community becomes dominated by mussels

(d) the Acorn Barnacle population increases in size

Some species in the intertidal zone are mobile, while others are sessile, and this affects how individuals compete with each other. Which of the following compete for space on intertidal rocks?

a. algae and starfish

b. whelk and starfish

c. mussels, whelk, and chiton

d. algae and barnacles

Where in a phylogenetic tree would you expect to find the organism that had evolved most recently? a. at the base, b. within the branches, c. at the nodes, d. at the branch tips.

The first forms of life on Earth were ________.

Two ice skaters, Daniel (mass 65.0 kg) and Rebecca (mass 45.0 kg), are practicing. Daniel stops to tie his shoelace and, while at rest, is struck by Rebecca, who is moving at 13.0 m/s before she collides with him. After the collision, Rebecca has a velocity of magnitude 8.00 m/s at an angle of $53.1 ^ { \circ }$ from her initial direction. Both skaters move on the frictionless, horizontal surface of the rink. (a) What are the magnitude and direction of Daniel’s velocity after the collision? (b) What is the change in total kinetic energy of the two skaters as a result of the collision?