A. The different length and different sequence are a good indication they are front different genes and probably have different functions.
Answer:
Unconditioned stimulus.
Explanation:
Classical conditioning may be defined as a type of learning procedure in which the biological procedure is used to pair up with the previous nerve stimulus. This stimulus result in the response of an individual.
The Pavlov experiment with the dog explains the process of classical conditioning. The ringing of bell (conditioned stimulus) is paired with unconditioned stimulus (meat presentation).
Thus, the meat presentation is unconditioned stimulus.
Despite their seemingly simple anatomy and radial symmetry Sea urchins and sea star are a type of deuterostome, closely related to the chordates.
What are the characteristics of deuterostome?
Animals classified as deuterostomes share a common embryonic development.
The first opening during development known as the blastopore changes to the anus in deuterostomes while the mouth changes in protostomes.
They have a coelom, which forms as a result of enterocele (coelom from the digestive tract).
These creatures include the following,
- Chordata,
- Echinodermata,
- Hemichordata.
Hence the correct answer is Deuterostome.
Learn more about Deuterostome,
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