Answer:
d. viriod
Potato spindle-tuber disease, which causes potatoes to become gnarled and cracked, is caused by an infectious agent consisting of a small circular RNA molecule that totally lacks a protein coat. These infectious agents are thought to exert their effects by interfering with the cell's normal path of gene expression. Such an infectious agent is known as a(n): <u>viriod</u>.
Explanation:
Viriods are very small , covalently closed, circular RNA molecules capable of autonomous replication and induction of disease.
They range in size from approximately 20nm and are infectious particles.
They consist only of Nucleic acid (RNA) and exert their effects by interfering with the cell's normal path of gene expression.
They mainly cause diseases in Plants.
As in the potato spindle-tuber disease, the infectious agent has all the characteristics as that of a virioid. Hence <u>Viriod</u> is the right choice.
Answer:
Endotherms & ectotherms
Most animals need to maintain their core body temperature within a relatively narrow range.
Endotherms use internally generated heat to maintain body temperature. ...
Ectotherms depend mainly on external heat sources, and their body temperature changes with the temperature of the environment.
Explanation: For these animals, heat comes from outside (ecto-) their bodies—their environment provides their warmth. That means they require less food, and are consequently able to inhabit places that would be off-limits to endotherms.
Endotherm, so-called warm-blooded animals; that is, those that maintain a constant body temperature independent of the environment. The endotherms primarily include the birds and mammals; however, some fish are also endothermic.
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There are three types of microscope with the ability to produce three-dimensional images. The scanning electron microscope<span> (</span>SEM<span>) and </span>transmission electron microscope<span> (</span>TEM<span>) both use beams of electrons to produce an image of the sample. The </span>confocal<span> laser scanning microscope uses a laser beam to produce an image.</span>
The answer would be no, because if evolution did occur in this situation, then habitats could just as well change, and evolution helps organisms to adapt to change.