Question

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) __________.
a) provirous
b) bacteriophage
c) viroid
d) virunette
e) eviscerion

Answer 1

Potato spindle-tuber disease is caused by a viroid, which is a small circular RNA molecule that lacks a protein coat. Viroids infect plants and interfere with the cell's normal gene expression. They are spread when infected knives are used to cut healthy potatoes.

Step-by-step explanation:

The infectious agent that causes potato spindle-tuber disease is a viroid. Viroids are small, single-stranded circular RNA particles that lack a protein coat. They infect plants and take control of the host machinery to replicate their RNA genome.

Viroids are much simpler than viruses and do not manufacture any proteins. They only produce a single, specific RNA molecule. Potato spindle tuber viroids (PSTVs) cause potatoes to become gnarled and cracked by interfering with the cell's normal gene expression pathway. Viroids are significant in agriculture due to their impact on crop yields and the economy.

Viroids are typically spread when infected knives are used to cut healthy potatoes, which are then planted.