In Order to Test How Sea Urchin Sperm Bind to Eggs

question 10

Multiple Choice

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

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Definitions:

Epimysium

A layer of connective tissue that surrounds skeletal muscles, providing structural support and protection.

Perimysium

A sheath of connective tissue that groups muscle fibers into bundles or fascicles within a muscle.

Endomysium

A thin layer of connective tissue that surrounds each individual muscle fiber, providing support and maintaining the spatial organization of muscle fibers.

Myofilaments

The filamentous components of muscles, comprising mainly of actin (thin filaments) and myosin (thick filaments), essential for muscle contraction.