Use the Following Information to Answer the Question

question 41

Multiple Choice

Use the following information to answer the question.
In order to test how sea urchin sperm bind to eggs, scientists isolated the egg receptor protein that binds to the sperm acrosomal protein called bindin. Plastic beads were coated with egg receptor for bindin (ERB1) from eggs of the sea urchin Strongylocentrotus purpuratus, and then the beads mixed with sperm from S. purpuratus or from the related species, S. franciscanus. The researchers counted how many sperm were bound to each bead. The results are shown in the graph below. (Adapted from Kamei and Glabe 2003)
Treatments:
A: S. purpuratus sperm mixed with S. purpuratus ERB1 beads
B: S. purpuratus sperm mixed with beads containing no ERB1 protein
C: S. franciscanus sperm mixed with S. purpuratus ERB1 beads
D: S. franciscanus sperm mixed with beads containing no ERB1 protein

Based on the description of the experiment, which of the treatments would be considered a "control" treatment for S. purpuratus sperm binding?

• A) Treatment A
• B) Treatment B
• C) Treatment C
• D) Treatment D

---

Definitions:

Systolic Blood Pressure

The pressure in the arteries when the heart beats, noted as the higher number in a blood pressure reading.

Weekly Weight

A measure of a person's body weight recorded on a weekly basis to monitor changes over time.

Refeeding

The process of reintroducing food after a period of malnutrition or starvation, which must be done carefully to prevent Refeeding Syndrome, a potentially fatal condition.