Answer:
When Earth passes directly between the sun and the moon, a lunar eclipse takes place. During a solar eclipse, the moon casts two shadows. One is called the umbra; the other is called the penumbra. An eclipse takes place when Earth or the moon passes through a shadow.
Explanation:
To clarify, you should read the directions that come with the lab activity to be sure of what to do in the lab.
Possibly Seed germination
Calcium ions are involved in many mechnisms: for example, stabilization of cell wall structures, acidic growth, ion exchange properties, control of the activities of wall enzymes. All these properties originate from the tight binding of calcium ions to the pectins present in the cell walls.