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

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

Quizplus · Accepted Answer

Treatment B, where S. purpuratus sperm are mixed with beads containing no ERB1 protein, would be considered the control treatment. This is because it allows the researchers to determine the baseline level of sperm binding in the absence of the specific egg receptor protein. By comparing the results of Treatment A (where S. purpuratus sperm are mixed with S. purpuratus ERB1 beads) to Treatment B, the researchers can determine how much binding is specifically due to the presence of the ERB1 protein.

In Order to Test How Sea Urchin Sperm Bind to Eggs