<span>During the twentieth century, absolute date was added to the relative time scale. </span>Geologic time scale uses both relative and absolute dating techniques. <span>Soon after the discovery of radioactivity, geologists used radioactive isotope decay to develop a method for determining absolute ages of rocks</span>
They are examples of precipitation
The ciliates<span> have both a </span>micronucleus<span> and </span>macronucleus<span>, which appear quite homogeneous in composition. The organelles of protozoa have functions similar to the organs of higher animals. The </span>plasma membrane<span> enclosing the </span>cytoplasm<span> also covers the projecting locomotory structures such as </span>pseudopodia<span>, </span>cilia<span>, and </span>flagella<span>.
</span>
