Of the following, a ____________ is present in plants and animals but not in bacteria.

Of the following, a ____________ is present in plants and animals but not in bacteria.

• A. Nucleus
• B. Chloroplast
• C. Mitochondrion
• D. Cell wall

Answer: (A)

The main idea here is the difference between eukaryotic and prokaryotic cells. A nucleus is a membrane-bound compartment that houses the cell’s DNA and helps regulate activities by separating genetic material from the rest of the cell. This feature is found in plants and animals, which are eukaryotes, but not in bacteria, which are prokaryotes and do not have a true nucleus—their DNA sits in a region called the nucleoid without a surrounding membrane. Why the other options don’t fit as the distinguishing feature: chloroplasts are used for photosynthesis and are present in plants (and some algae) but not in animals; mitochondria occur in both plant and animal cells, so they wouldn’t distinguish bacteria from those two groups; a cell wall is common in plants and bacteria but not in animal cells, so it doesn’t consistently separate plants and animals from bacteria. The nucleus is the only feature that plants and animals share that bacteria lack.

The main idea here is the difference between eukaryotic and prokaryotic cells. A nucleus is a membrane-bound compartment that houses the cell’s DNA and helps regulate activities by separating genetic material from the rest of the cell. This feature is found in plants and animals, which are eukaryotes, but not in bacteria, which are prokaryotes and do not have a true nucleus—their DNA sits in a region called the nucleoid without a surrounding membrane.

Why the other options don’t fit as the distinguishing feature: chloroplasts are used for photosynthesis and are present in plants (and some algae) but not in animals; mitochondria occur in both plant and animal cells, so they wouldn’t distinguish bacteria from those two groups; a cell wall is common in plants and bacteria but not in animal cells, so it doesn’t consistently separate plants and animals from bacteria. The nucleus is the only feature that plants and animals share that bacteria lack.