Fate Mapping of Blastomere in Sea Urchins

Use the passage to answer the question.

Based on the results, which conciusion is correct?

(1 point)

in sea urchins, only the fate of the ectodermar cells is conserved

In sea urchins, onty the fate of the endodermal cells is conserved

In sea urchins, the fate of the ectodermal ano mesodermal cells is conserved

in sea urchins, the fare of the three gem layers is conserved between the two cianes

Fate mapping is a technique that allows determination of the fare of cells from the three germ layers. in worms, the endoderm gives rise to the cells that line the intestines. The ectoderm gives nse to cells of the nervous system and body covering. The mesoderm gives rise to the muscles and other organs between the ectoderm and mesoderm. A researcher is tracing the fate of a particular cell (brastomere) from its position in one of the three germ layers of sea urchin biastulae by Injecting a fluorescent tag in cells of the ectoderm, mesoderm, and endoderm. Several weeks later, the sea urchin embryos were analyzed for the presence of fluorescence in specific tissues. The following results were obtained.

Percent increase fluorescence over background when dye is injecred in the endoderm

3%

70%

Percent Increase fluorescence over background when dye is injected in the mesoderm

5%

5%

Percent Increase fluorescence over background when aye is Injected in the ectoderm

Tissue

40%

Nerve ring

Intestinal

89%

60%

7%

10%

47%

ning

Nerve coras

Water

Vascular System

Tube feat

Epidermis

40

6%

00%

40%

17%

9%

6%

8%

covering

jendaskeleton

In sea urchins, the fate of the ectodermal and mesodermal cells is conserved between the two stages.