25) D hypertonic
23) active transport
Those are the ones I know (sorry I couldn't help with the other ones... I'm studying for my exam) ^-^
Answer:
The influx of calcium ions.
Explanation:
The influx of calcium ions at a certain point produces phase of the action potential also called depolarization which results in the ion movement changes the membrane potential from negative to positive inside the cell.
In action potential, calcium ions may control gene transcription, cell excitability, and neurotransmitter release. In chemical synapses, the influx of calcium ions leads to vesicles filled with neurotransmitters move to the surface of the cell, and into the synaptic cleft release their contents.
Answer: The tracheids have important functions in the plant.
Explanation: The mechanical support is provided by the lignified walls of tracheid cell. the helps in other functions of the plant such as transporting water and getting the solute from the root to the stem and eventually the leaf of the plant.
The tracheids are most useful in the gymnosperms where elements need to be transported.
Identifying a tracheid in a cross section is quire easy as the tracheid cells fit into each other neatly and piled up similarly and have identical shapes as well which makes them obvious from other cells.
The two examples of tracheid plans could be
The most common thing that could be found in traceid plant is that this cells are mainly present for transporting either water other solutes in the plant body.