Explanation:
Determining a substance's physical or chemical identity. What are the two main requirements for identification? The adoption of testing procedures that give characteristic results for specific standard materials and the number and type of tests needed to identify a substance to exclude all other substances.
Answer:
A. Tissue
Explanation:
The cells join together to form tissues. So, option (A) is the correct answer.
Answer:
Linings of hollow organs
Explanation:
Smooth muscle cells are usually found in the lining of hollow organs such as all arteries and veins, wall of stomach, uterus, urinary bladder, digestive system etc. The cells of these linings are spindle shaped and consist of a nucleus at the center which lacks striations.
They work as a housekeeper and are under involuntary control except the heart. They lack striation because of irregular arraying of actin and myosin filament along the length of the cell.
The cyanobacteria changed the composition of the earth’s atmosphere by evolving oxygen in what is referred to as the Great Oxygenation Event. This also allowed the ozone to be formed and block off most of the UV rays that are destructive to genetic material. Life was, therefore, also able to exist on land other than in water.
