<span>Cattle and sheep are exposed to lead and zinc when these poisons are in the grass/soil.
Cattle and sheep graze on the grass, and thus they intake these minerals, such as lead and zinc when they come in contact with grass or earth they may eat along with grass. Thus they are exposed to them via eating.
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<span>Yes, both prokaryotes and eukaryotes have liquid cytoplasm in their construction. To the best of my knowledge, AT LEAST MOST viruses do as well, if not all. However, their cell structures are relatively primitive and their cytoplasm is viscous and granular.</span>
The correct answer is none of the above.
Bacterial cells can transfer genetic material through a process called bacterial conjugation. This process involves the direct physical contact of the bacterial cells and a horizontal gene transfer. The genes which are transferred are most of the times beneficial for the recipient, such as genes for antibiotic resistance.
In this example, bacterial cells cannot have physical contact, since they are separated by a glass filter. Therefore, the bacterial conjugation cannot happen. Given that no gene transfer can be achieved, the AY strain remains bio- trp- and is unable to grow on any medium that lacks bio or/and trp.
Example answer number one
<span>If I were attempting to date a rock sample that I suspect to be incredibly old, i would use radioactive isotopes with a long half life. When dating rocks and fossils to discover approximately how old they are, radioisotope dating is used on igneous rocks found near fossils. Things like Uranium 235, which is an unstable radioactive isotope of elements, decays at a constant rate over time so can be useful in determining age.</span>
