Answer:
b. di uses across a synaptic cleft from a neuron to a muscle cell.
Explanation:
A neurotransmitter is di uses across a synaptic cleft from a neuron to a muscle cell. Neurotransmitters are chemicals which enable neurotransmission. In reaction to an impulse a motor neuron axon secretes a neurotransmitter and causes the muscle fiber to contract. It is a chemical messenger which passes on the signals across the chemical synapse.
Answer:
auxin
Explanation:
i am not that dumb i just over looked it
Answer:
Microbial mats.
Explanation:
Microbes formed sheets that were able to capture layers of sediment is called microbial mats. These mats of microbes provide good fossil evidence to the researchers. These microbial mats consist of bacteria and archaea which is considered the earliest form of life on earth. These microbial mats grow on moist places as compared to dry environment. About 3,500 million years ago, these microbes are the most important members of earth and maintainers of the ecosystems.
