The correct answer is: D) Binding of the neurotransmitter causes chemically gated sodium channels to open in the motor end plate (junctional folds of the sarcolemma) and sodium enters the cell.
The motor neuron cell is connected to muscle cell via synaptic cleft, where neurotransmitter is released. The muscle side of this synapse is called motor end plate. Released neurotransmitter is acetylcholine and it binds to its receptor (ACh receptor) on the motor end plate. As it binds, ion channels open, and Na+ gets into the muscle cell. This event reduces the voltage difference between the inside and outside of the cell and causes depolarization which creates a wave through the entire muscle cell (its membrane-sarcolema). As a consequence, Ca2+ is released from the sarcoplasmic reticulum which will cause the contraction of the muscle cell.
Answer:HOW DO INFECTIOUS MICROORGANISMS CONTAMINATE DRINKING WATER? animal waste. Wells and other drinking water sources can be contaminated by storm water run-off from roadways, farms and livestock operations, discharges from sewage treatment plants, or septic system discharges.
Answer:
Nitrogen and Phosphorus
Explanation:
When the function of a whole ecosystem is limited because of a nutrient , which is present in limited amount, it is called as a limiting nutrient. The organisms uptake water and carbon directly from the environment as it is abundant in nature. The nutrients like nitrogen and phosphorous are present in limited amount and moreover they are not present in the form that can be directly taken up by the organism.
Thus, Nitrogen and Phosphorous are limiting nutrients.
