Answer:
There is little to no sunlight in the aphotic zone.
Explanation:
The aphotic zone is the deepest part of a lake/ocean, so no light is able to penetrate into those depths. Without light, photosynthetic organisms will not be able to undergo photosynthesis and will therefore not be able to survive.
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.
Two criteria that would identify the three muscle tissues are myofibers and nuclei.
There are three types of muscles:
1. Skeletal-Contains many nuclei along the length of the muscle cell. The nuclei are displaced peripherally. The skeletal fibers are arranged parallel. The myofibril is composed of bands.
2. Smooth-This tissue contain spindle-shaped cells with a single central nucleus. Smooth muscle fibers are shorter than skeletal.
3. Cardiac-The fibers of cardiac muscle are not simply parallel. Cardiac muscle fibers are long cylindrical cells with one or two nuclei.
Answer:
toooo blurryyyy post another pic but clear
Explanation:
