Answer:
Animals needs oxygen's to survive and plants need carbon dioxide to survive. The ozone layer reflects harmful UV rays from the sun to protect the things living on Earth.
Answer:
1. Nerve impulse
2. Neurons
Explanation:
Neurotransmitters are compounds with low molecular weight. They are secreted by axon terminals of the neurons. The released neurotransmitters then bind to the receptors located on next neuron or on the surface of muscle cell.
The function of neurotransmitters is to carry the nerve impulse from presynaptic neuron to the postsynaptic neuron or from neurons to the effector organs such as muscles and glands.
For example, neurotransmitters are released into the synaptic cleft to transmit the nerve impulse between neurons.
Answer:
Invertebrates include all animals that lack a backbone, or a vertebral column. All chordites exhibit four characteristics during at least one stage of life: a dorsal, hollow nerve chord; a notochord; a tail that extends beyond the anus; and pharyngeal pouches.