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. 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?

#Question id: 2771

#Unit 2. Cellular Organization

For SINES (short interspersed elements), which of the following is correct

a. are approximately 300 base pairs long

b.  are LTRs containing retrotransposons.

c. are present in over 1 million copies in the human genome.

#Question id: 2772

#Unit 2. Cellular Organization

Mobile DNA elements likely contributed to the evolution of higher organisms by the

#Question id: 2773

#Unit 2. Cellular Organization

Which of the following is an algorithm designed to compare the sequence of a newly identified protein with sequences already stored in the GenBank database?

#Question id: 2774

#Unit 2. Cellular Organization

The DNA and protein sequences of the -tubulin genes in humans and in fish are similar, and because each arose due to speciation, these genes would be considered:

#Question id: 2775

#Unit 2. Cellular Organization

To examine the folding and compaction of chromatin during mitosis, you will need to isolate and stain chromosomes at a particular stage using a special spreading preparation technique. For the best analysis, the chromosomes must be at which one of the following stages?

#Question id: 2776

#Unit 2. Cellular Organization

There are five major types of histone proteins, but only four of them are considered as core histones. Which one of the following is NOT considered a core histone protein?