<span>d. by sending and detecting chemical messages</span>
Answer:
(a) X: Producers undergo photosynthesis. Y: Decomposers return carbon to the soil and release waste.
Explanation:
<em>(a) X: Producers undergo photosynthesis. Y: Decomposers return carbon to the soil and release waste.
</em>
<em>(b) X: Decomposers return carbon to the soil and release waste. Y: Producers undergo photosynthesis.
</em>
<em>(c) X: Decomposers take in carbon dioxide. Y: Producers absorb carbon through their roots.
</em>
<em>(d)X: Producers absorb carbon through their roots. Y: Decomposers take in carbon dioxide.
</em>
<u>Box 2 (X) would be the process through which producers fix carbon dioxide to produce their own food, the carbohydrate. T</u>he process is otherwise known as photosynthesis and can be represented by the following equation:

<u>Box 4 (Y) would be the process of decomposition.</u> Both producers and consumers eventually die and decompose in the soil. During this process, some of the carbon returns to the soil as organic matters while the process of microbial decomposition releases carbon dioxide into the atmosphere.
The correct option would be (a).
The cell cycle, or cell-division cycle, is the series of events that take place in a cell leading to its division and duplication of its DNA (DNA replication) to produce two daughter cells.
Answer:
Calcium voltage gated ion channels
Explanation:
There are two types of ion channels involved in the neuromuscular junction and end plate potentials: voltage-gated ion channel (responsive to changes in membrane voltage which cause the voltage gated ion channel to open) and ligand-gated ion channel (responsive to certain molecules such as neurotransmitters).
The resting membrane potential of a motor neuron goes from -70mV to -50 with a higher concentration of sodium outside and a higher concentration of potassium inside. <em>When an action potential propagates down a nerve and reaches the axon terminal of the motor neuron, the change in membrane voltage causes the calcium voltage gated ion channels to open allowing for an influx of calcium ions. </em>These calcium ions cause the acetylcholine vesicles to release acetylcholine via exocytosis into the synaptic cleft.
I hope you find this information useful and interesting! Good luck!