Answer:
A. Chloroplasts.
Explanation:
Chloroplasts are organelles found in leaves of green plants and they conduct photosynthesis. They contain chlorophyll pigment which captures sunlight and convert it to energy.
Photosynthesis is the process whereby green plants manufacture their food from carbon dioxide and water in the presence of sunlight and they release the oxygen.
So, in the presence of chloroplast, photosynthesis takes place and oxygen is released into the atmosphere.
Water-soluble is when something is able to dissolve in water.
Answer:
The source of Calcium (Ca⁺⁺) for the skeletal muscle cells is the sarcoplasmic reticulum, the main store of intracellular Ca⁺⁺.
Explanation:
Calcium (Ca⁺⁺) is an ion that plays an important role in muscle contraction, a process that requires high cytoplasmic concentrations of this ion to promote myofibrillary activity.
The sarcoplasmic reticulum (SR) -equivalent to the endoplasmic smooth reticulum- is an organelle that regulates the contractile activity of skeletal muscle. The two terminal cisterns of the SR attach to the T-tube, forming a triad, which surrounds the myofibrilla.
Once the muscle cell receives the signal to contract, the Ca⁺⁺ channels are opened and allow Ca⁺⁺ to enter the cell, promoting the exit of this cation from the SR and increased its cytoplasmic levels. This stimulates muscle contraction.
Answer:
The trilobite is the oldest.
Explanation:
In general terms (disregarding specific examples), the lower the level in the stratosphere, the older it is. In this case, the lowest level is taken by the trilobite.
Note however, that this is not always the case, especially near edges of the plates. Sometimes plates shift, which can cause certain older fossils to be moved upwards, while newer ones are shifted downward, as one plate "eats the other". Territory creations, including valleys and mountains when plates crash into each other, can also shift where a fossil is located.
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90% hatch and 1% survival rate up to sexual maturity
