Question

Choose the correct statements among the following
A) Bacteria flagella can shorten itself once in contact with other bacterium.
B) Griffith experiments revealed the DNA as genetic material.
C) Spirochetes are slender, long and flexible.
D) Chemoheterotrophs derive only carbon from organic compounds.

• A. A, B
• B. B, C
• C. C, D
• D. B, D

Hint:

Eukaryotic flagella move via bending (tubulin-dynein sliding).
Prokaryotic flagella move purely via rotation powered by a proton motive force at the basal body. They never contract or shorten.

Answer 1

The Correct Option is B

Step 1: Test the flagella statement.
Bacterial flagella are rigid helical filaments built from flagellin that rotate like a propeller, they do not contract or shorten on contact. So statement A fails.
Step 2: Test the Griffith and Spirochete statements.
Griffith's transformation experiment on pneumococcus bacteria is the classic study that pointed to a hereditary transforming principle carried in DNA, so statement B holds. Spirochetes are indeed long, slender and flexible spiral bacteria, so statement C holds too.
Step 3: Test the chemoheterotroph statement.
Chemoheterotrophs get both their carbon and their energy from organic compounds, not carbon alone, so statement D is incomplete and false.
Step 4: Combine.
Only B and C hold up under scrutiny.
Final answer: Option 2, B and C.