Which of the following is a main characteristic of foraminiferans?

• A. They are photosynthetic prokaryotes.
• B. They possess intricate shells made primarily of calcium carbonate.
• C. They lack a nucleus and other membrane-bound organelles.
• D. They reproduce exclusively by binary fission.

Answer: (B)

Verified step by step guidance

1. Identify the group in question: Foraminiferans are a type of protist, which are eukaryotic microorganisms.
2. Recall the key characteristics of foraminiferans: They are known for their complex shell structures, called tests, which are primarily composed of calcium carbonate.
3. Understand that foraminiferans are not prokaryotes, so they do have a nucleus and membrane-bound organelles, which rules out options stating they lack these features.
4. Recognize that foraminiferans are not photosynthetic organisms; they obtain nutrients by other means, so the photosynthetic prokaryote option is incorrect.
5. Note that foraminiferans reproduce through various methods, including multiple fission and sexual reproduction, not exclusively by binary fission, which is typical of prokaryotes.