Just Prior to the Onset of Gastrulation in an Embryo

question 18

Multiple Choice

Just prior to the onset of gastrulation in an embryo, the "organizer" cells are specified. If you were to experimentally block the specification of these cells, what would you expect the result to be in the developing embryo?

• A) There would be no effect on development.
• B) Gastrulation would not occur, and normal development would cease.
• C) The body axes would develop normally, but the embryo would not grow appendages.
• D) The embryo would not develop an intestine, but all other organs and tissues would develop normally.

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Definitions:

Crustal Expressions

Refers to the physical features present on the Earth's crust, which are a result of various geological processes.

Magma Chamber

A large underground pool of liquid rock found beneath the surface of the Earth.

Molten Rock

Rock that has been heated to a temperature where it becomes liquid, known as magma beneath the Earth's surface and lava when it erupts.

Underground Body

A mass of geologic material beneath the Earth's surface, such as rock formations, ore bodies, or aquifers.