To determine the best descriptions for \(X\) and \(Y\) in the table, we need to understand the common shapes and associated bacteria for each form listed.
1. Coccus:
- The shape associated with coccus bacteria is spherical.
- So, \(X\) is best described as spherical.
2. Bacillus:
- Bacillus describes rod-shaped bacteria.
- There are numerous types of rod-shaped bacteria, but one commonly known type is E. coli, which is well-known in scientific and medical contexts.
3. Spirillum:
- The shape of spirillum bacteria is spiral.
- This is associated with diseases such as cholera.
Given these explanations, the best descriptions for \(X\) and \(Y\) are:
[tex]\[
\begin{aligned}
X & = \text{Spherical} \\
Y & = \text{E. coli}
\end{aligned}
\][/tex]
Thus, the complete answer is:
[tex]\[ X = \text{Spherical} \][/tex]
[tex]\[ Y = \text{E. coli} \][/tex]
The correct choice from the options provided is:
[tex]\[ X = \text{Spherical}; Y = \text{E. coli} \][/tex]
