Question

the head of a tapeworm intestinal parasite is known as the _______.
proglottid
scolex
cysticerci
spicule
question 12 (1 point)
streptococcus mutans is a major cause of cavities. it resides in the gum pockets, does not have catalase activity, and can be grown outside of an anaerobic chamber. the bacterium is probably which of the following?
obligate anaerobe
thermophilic aerobe
aerotolerant anaerobe
facultative halophile

Explanation:

First Question (Tapeworm Head)

To answer the first question, we recall the anatomy of a tapeworm. The head of a tapeworm (an intestinal parasite) is called the scolex. Proglottids are the body segments, cysticerci are larval forms, and spicules are structures in other organisms (e.g., nematodes for reproduction). So the correct option is the one with "scolex".

1. Analyze each option:

• Obligate anaerobes cannot grow in the presence of oxygen. But Streptococcus mutans can be grown outside an anaerobic chamber, so it's not an obligate anaerobe.
• Thermophilic aerobes are heat - loving and require oxygen; Streptococcus mutans is not thermophilic (it lives in the mouth, a moderate - temperature environment) and the question states it has no catalase activity (not typical of aerobes that use oxygen fully).
• Aerotolerant anaerobes do not use oxygen but can tolerate its presence. Streptococcus mutans has no catalase (so it doesn't use oxygen for respiration) and can be grown outside an anaerobic chamber (tolerates oxygen), which fits the definition of an aerotolerant anaerobe.
• Facultative halophiles can tolerate high salt but there's no indication of salt tolerance in the question, so this is not relevant.

Answer:

B. scolex (assuming the second option is labeled B; if the original labels were different, adjust accordingly, but based on the options, the correct one is "scolex" which is the second option here)

Second Question (Streptococcus mutans Classification)