Let's go through each of the provided options carefully to determine the best descriptions for [tex]\( X \)[/tex] and [tex]\( Y \)[/tex].
1. Option 1: [tex]\( X = \)[/tex] Spherical; [tex]\( Y = \)[/tex] E. coli
- We need to identify what "Coccus" and "Bacillus" mean based on their shapes and associations.
- "Coccus" is known to refer to spherical or round-shaped bacteria.
- "Bacillus" refers to rod-shaped bacteria, and E. coli is indeed a rod-shaped bacterium commonly found in the intestines of humans and animals.
2. Option 2: [tex]\( X = \)[/tex] Comma shaped; [tex]\( Y = \)[/tex] Whooping cough
- "Coccus" does not refer to a comma shape; it refers to spherical or round shapes.
- "Bacillus" refers to rod-shaped bacteria, and though Bordetella pertussis (the agent causing whooping cough) is a coccobacillus (short rod-shaped form), this doesn't fit the typical description.
3. Option 3: [tex]\( X = \)[/tex] Oval shaped; [tex]\( Y = \)[/tex] S. aureus
- "Coccus" does not refer specifically to oval shapes but to spherical shapes.
- S. aureus is a coccus type of bacteria, not a bacillus, so this association is incorrect.
4. Option 4: [tex]\( X = \)[/tex] Rod shaped; [tex]\( Y = \)[/tex] Pneumonia
- As mentioned, "Coccus" refers to spherical shapes and not rod shaped.
- Pneumonia can be caused by various bacteria, including Streptococcus pneumoniae, which is coccus-shaped.
Thus, the best descriptions from the options would be:
- [tex]\( X = \)[/tex] Spherical (as "Coccus" refers to spherical)
- [tex]\( Y = \)[/tex] E. coli (as "Bacillus" refers to rod-shaped bacteria and E. coli fits this description)
Therefore, the correct option is:
[tex]\[ X = \text{Spherical}; Y = \text{E. coli} \][/tex]
