Bacteria with two or more flagella at one or both ends are called
(A) amphitrichous (B) peritrichous (C) lophotrichous (D) atrichous
Options:
(A) amphitrichous
(B) peritrichous
(C) lophotrichous
(D) atrichous
Official Answer Key:
B
Step-by-Step Solution & Explanation
### **Official Solution & Step-by-Step Derivation (GATE BT 2016 Q.01)**
**1. Governing Concept & Question Classification**:
- **Section**: General Aptitude (GA)
- **Question Type**: **MCQ** (1 Mark)
- **Topic**: English Grammar & Degree of Comparison (Comparative Adjectives)
**2. Detailed Step-by-Step Derivation**:
- Let us compare the volumes of the two geometric objects:
- For a sphere of diameter $d = 1$ unit, radius $r = 0.5$ unit:
$V_{\text{sphere}} = \frac{4}{3} \pi r^3 = \frac{4}{3} \pi (0.5)^3 = \frac{4}{3} \times \frac{1}{8} \pi = \frac{\pi}{6} \approx \frac{3.1416}{6} \approx 0.5236\text{ units}^3$
- For a cube of side $s = 1$ unit:
$V_{\text{cube}} = s^3 = 1^3 = 1.0\text{ units}^3$
- Since $0.5236 < 1.0$, the volume of the sphere is smaller than that of the cube.
- Grammatical construction: The sentence uses the comparative conjunction **“than”** (*“...is ________ than the volume of a cube...”*).
- The standard comparative degree of the adjective "little" or "low" when comparing two quantities followed by "than" is **less**.
- "Lesser" is an archaic/attributive adjective (e.g., "the lesser of two evils") not used directly before "than".
- "Least" is superlative; "low" is positive degree.
- Therefore, the grammatically and mathematically correct choice is **less**.
- **Option-by-Option Evaluation**:
- **Option (A) [INCORRECT]**: *"least"* is the superlative degree used for three or more items.
- **Option (B) [CORRECT]**: *"less"* is the correct comparative form preceding "than".
- **Option (C) [INCORRECT]**: *"lesser"* is not followed by "than" in standard modern grammar.
- **Option (D) [INCORRECT]**: *"low"* is positive degree and cannot precede "than".
**3. Final Answer / Verification Summary**:
- **Official GATE Answer Key**: **B**
- **Scoring Criteria**: +1.0 Mark (Negative marking: -0.33 marks).
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