Which bacteria arranged in curved lines resembling a string of beads cause infections such as strep throat and blood poisoning?

• A. Streptococci
• B. Spirilla
• C. Bacilli
• D. Cocci

Answer: (A)

A string of beads describes Streptococcus bacteria. These are spherical (cocci) that divide in a way that keeps the cells attached in long chains, giving that curved, bead-like appearance under a microscope. The name itself comes from strepto- meaning twisted or chain, and -coccus meaning spherical bacterium. This chain arrangement is what distinguishes them from other shapes: Spirilla are spiral-shaped, bacilli are rod-shaped, and cocci alone simply describes spherical forms that don’t specify the chain pattern. Streptococci cause infections such as strep throat and can lead to bloodstream infections, which is why this description points to them.