"27 days, 7 hours, and 43 minutes for our Moon to complete one full orbit around Earth"
Answer:
The phases of the Moon depend on its position in relation to the Sun and Earth. As the Moon makes its way around the Earth, we see the bright parts of the Moon's surface at different angles.
Explanation:
The correct answer is A.
Animal cells do not have a cell wall.
A cell wall is the rigid, outermost covering of plant cells and is made up of cellulose. It is absent in animal cells. The cell wall is visible under a light microscope.
Animal cells are instead covered by a cell membrane. It is made up of lipids, proteins, and small amounts carbohydrates. It is a thin and delicate structure that can only be seen using an electron microscope.
Answer:
b) opening calcium pores in the membrane
Explanation:
The opening of calcium ions channels facilitates the migration of vesicles containing neurotransmitters in the pre-synaptic neurons to the tip of the post-synaptic membrane. at the <u>neuromuscular junction </u>These neurotransmitters can either be <u>cholinergic or non-chorlinergic.</u> <u>At the tip of the pre-synaptic membranes the vesicles empty their neurotransmitter contents into the synapse.</u>
The neurotransmitters, diffuse through the neuromuscular junction to bind with the receptors on the <u>post-synaptic membrane on the post-synaptic neuron.</u> This stimulates opening of<u> ligand gated sodium ions,</u> and sodium ions diffuse into the post-synaptic neuronal membrane, to cause <u>depolarization</u>. if the stimulus is up to the threshold levels it generate action potential.
Therefore , more calcium ions channels opening produces; more diffusion of neurotransmitters;leading to opening of more sodium channels for depolarization; and IPSP or EPSP generation.
