Question

Animals with nerve nets have A. no specialized neurons. B. sensory neurons but no interneurons. C. interneurons but no sensory neurons. D. only motor neurons

Answer 1

Animals with nerve nets have neurons with mixed functions, both sensory and motor, unlike more complex nervous systems that have specialized neurons. The options given do not accurately describe the composition of a nerve net, since cnidarian nerve cells display mixed characteristics.

Step-by-step explanation:

Animals with nerve nets, such as jellyfish, have a simplified nervous system without a central brain. These networks consist of interconnected neurons that function in a decentralized manner, controlling the animal's movements and responses to environmental stimuli. Although nerve nets do not have specialized neurons like those found in more complex nervous systems, cnidarian nerve cells display mixed characteristics that are both sensory and motor in nature. Hence, the most accurate answer to the question, 'Animals with nerve nets have,' would be:

• A. no specialized neurons. Incorrect—there are neurons, but they are not centralized.
• B. sensory neurons but no interneurons. Incorrect—nerve cells show mixed characteristics.
• C. interneurons but no sensory neurons. Incorrect—nerve cells show mixed characteristics.
• D. only motor neurons. Incorrect—nerve cells show mixed characteristics.

The correct answer, which is not listed as an option here, would be that nerve nets consist of neurons that have both sensory and motor functions. Unfortunately, none of the provided options correctly describe the nervous system of animals with a nerve net.

Answer 2

The correct answer is option (A) no specialized neurons.

Nerve net refers to the simplest and the primitive form of the nervous system found in multicellular oraganisms. It is found in the members of Cnidaria, Ctenophora and Echinodermata. Nerve net provides the ability to sense objects, food particles by the presence of the sensory neurons in it. A nerve net is made up of diffuse network of cells forming a ganglion but does not form a brain. Since it does not form a brain it lacks the specialized neurons. It is made up of the sensory neurons that sense the stimulus and the motor neurons that produce a reaction to the stimulus.