Which of the following illustrates the principle of induction in invertebrates?

A. In an embryo, the presence of a notochord beneath the ectoderm results in the formation of a neural tube.
B. A neuron synapses with another neuron via a neurotransmitter.
C. Eye muscles constrict in response to light.
D. Secretion of TSH stimulates the secretion of thyroxine.
E. The maternal parent induces spontaneous expression of recessive genes.


Sagot :

Answer:

A

Explanation:

A

How does the ectoderm that will make up the future eye know to develop into an eye? The cells are "told" to develop into an eye because the nearby retina releases chemical signals that direct the development of the cells. This process is called induction. Choice A depicts a similar situation. The notocord releases chemical signals that tell the overlying ectoderm that it is time for it to become the neural tube. None of the other choices depict the process of induction.