Answer:
Spread
Explanation:
People use envelopes very often. The germs people carry are put into the envelope and then it's sent out to many others.
<span>The mammalian sperm cell consists of a head, a midpiece and a tail. The head contains the nucleus with densely coiled chromatin fibres, surrounded anteriorly by an acrosome, which contains enzymes used for penetrating the female egg.</span>
Answer:
D) is the correct answer in my opinion
Answer:
1. opening Voltage gated channels
2. Calcium
Explanation:
The signals are transmitted in the neurons in the form of electrical signals and which are transformed into the chemical signals at the synaptic cleft.
The electrical signal is transformed into a chemical signal when the electrical impulse reaches the terminal of the axon and opens the calcium voltage channels. The calcium which is present in a higher amount than inside enter into the terminal and allows fusion of the synaptic vesicle carrying neurotransmitter and the neurotransmitter is released into the synapse.
The neurotransmitter then binds the receptors and initiates the electrical impulse in the postsynaptic neuron.
Thus, opening Voltage gated channels and Calcium is the correct answer.