UNIT 2

Which of the following is a characteristic of prokaryotic cells?

• Presence of mitochondria

• Absence of nuclear membrane

• Presence of endoplasmic reticulum

• Presence of nucleolus

What is the shape of Vibrio bacteria?

• Spherical

• Rod-shaped

• Curved/comma-shaped

• Spiral

The Gram staining technique was developed by:

• Louis Pasteur

• Robert Koch

• Hans Gram

• Anton van Leeuwenhoek

Why are gram-negative bacteria more resistant to antibiotics compared to gram-positive?

• Thicker peptidoglycan layer

• Presence of teichoic acid

• Protective outer shell with endotoxin release

• Absence of periplasmic space

Which of the following best differentiates eukaryotic from prokaryotic cells?

• Larger size and presence of organelles

• Ability to reproduce by binary fission

• Possession of a single circular chromosome

• Absence of sterols in cell membrane

Why is the bacterial cell wall important for survival?

• Produces energy for the cell

• Maintains osmotic balance and prevents lysis

• Facilitates DNA replication

• Assists in protein synthesis

A lab technician isolates a bacterium that is purple after Gram staining. This bacterium is most likely:

• Gram-positive

• Gram-negative

• Acid-fast

• Capsule-forming

Which of the following pairs is mismatched?

• Cocci – spherical

• Bacilli – rod-shaped

• Spirochetes – rigid spiral

• Spirilla – rigid spiral/helical

Which of the following arrangements correctly matches bacteria with their grouping?

• Streptococci – clusters

• Staphylococci – chains

• Pneumococci – pairs

• Bacillus anthrax – diplobacilli

A hospital patient on a ventilator develops a gram-negative infection. Which factor most likely contributed to this condition?

• Overuse of antibiotics at home

• Weak immune system due to hospital stay

• Normal flora imbalance in the throat

• Presence of teichoic acid in bacteria