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TLS Online TPP Program

#Question id: 7134

What important lesson for the mechanisms of development can we derive from the ability to clone frogs by nuclear transfer?

#Unit 5. Developmental Biology
  1. that the selective gene expression seen in differentiated cells does not result from an irreversible loss of genes, or their potential for expression
  2. that a piece of a frog can be "planted" to obtain a new, cloned individual, just like in plants
  3. that the pattern of gene expression in a differentiated cell can only be reversed if the nucleus is removed from the cell
  4. that the mechanisms of development are irreversible in all organisms except frogs
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TLS Online TPP Program

#Question id: 5642

#Unit 5. Developmental Biology

One of the earliest events in arabidopsis development is formation of the _____ axis, in response to a gradient of _____.
TLS Online TPP Program

#Question id: 5643

#Unit 5. Developmental Biology

The genetic analysis of arabidopsis development was strongly influenced by genetic analysis of Drosophila development, and as is the case in Drosophila, genes that influence development are often named for:
TLS Online TPP Program

#Question id: 5644

#Unit 5. Developmental Biology

If embryos are disaggregated with chemicals or proteases, and the individual cells are mixed together in culture, what will happen?
TLS Online TPP Program

#Question id: 5645

#Unit 5. Developmental Biology

A reproductive difference between sea urchins and humans is ________.
TLS Online TPP Program

#Question id: 5646

#Unit 5. Developmental Biology

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?
TLS Online TPP Program

#Question id: 5647

#Unit 5. Developmental Biology

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. 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 data in the graph, which of the following conclusions is supported?