Myocardium (cardiac muscle tissue) must rhythmically contract for a lifetime. this requires a considerable amount of energy production by the cells. you would expect to see a relatively high amount of which organelle in these cells?

Answer;

-Mitochondria

Explanation;

-Mitochondria are organelles, or parts of a eukaryote cell. They are in the cytoplasm, not the nucleus. They make most of the cell's supply of adenosine triphosphate (ATP), a molecule that cells use as a source of energy.

-Heart muscle cells have the most abundant mitochondria,with about 5,000 mitochondria per cell – that contain far more mitochondria than any other organ in body. This is because they are constantly-beating, heart works harder than any other organ in the body.

-Heart muscle cells have extra-special demand for ATP to keep the heart pumping 24/7 over a lifetime. By comparison, the tissue of the biceps muscle has about 200 mitochondria per cell.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c