Compare and contrast the general structures of plant and animal cells and of prokaryotic and eukaryotic cells (NGSSS SC.912.L.14.3; Reporting Category 1, Molecular and Cellular Biology).

What this topic is asking

The NGSSS benchmark SC.912.L.14.3 asks you to compare and contrast two pairs of cells: prokaryotic versus eukaryotic, and plant versus animal. For the Florida Biology 1 EOC you need to know what all cells share, the one feature that defines a eukaryote (the nucleus), and the short list of structures that separate a plant cell from an animal cell. This is a high-frequency Reporting Category 1 topic, and items usually give you a description or a diagram and ask you to classify the cell.

What all cells share

Because all cells share these, an EOC option that names one of them as a "difference" is a distractor. The differences live in what gets added on top of this shared base.

Prokaryotic versus eukaryotic cells

The deepest division among cells is whether the DNA is enclosed in a nucleus.

• Prokaryotic cells (bacteria and archaea) have no membrane-bound nucleus and no membrane-bound organelles. Their single circular chromosome floats in a region of the cytoplasm called the nucleoid. They are usually small and simple, and most have a cell wall.
• Eukaryotic cells (plants, animals, fungi, protists) have a true, membrane-bound nucleus that encloses the DNA, plus a set of membrane-bound organelles (mitochondria, endoplasmic reticulum, Golgi apparatus, and so on). They are usually larger and more complex.

The single most-tested fact in this whole topic is that the nucleus is the defining eukaryotic feature. Both cell types have DNA; only the eukaryote keeps it in a nucleus.

Plant versus animal cells

Plant and animal cells are both eukaryotic, so both have a nucleus, mitochondria, ribosomes, endoplasmic reticulum, and a cell membrane. The differences are a short, memorable list.

Plant cells have three structures animal cells lack:

• A cell wall of cellulose outside the membrane, which gives shape and support.
• Chloroplasts, where photosynthesis captures light energy to make glucose.
• A large central vacuole that stores water and helps keep the cell firm (turgid).

Animal cells have none of those three. (Animal cells do have small vacuoles and rely on centrioles for cell division, but the EOC focuses on the wall, chloroplasts, and large vacuole as the plant-only trio.)

So if a described cell has a cell wall, chloroplasts, and a big central vacuole, it is a plant cell; if it has a nucleus and mitochondria but none of that trio, it is an animal cell.

Try this

Q1. State two features that all cells, prokaryotic and eukaryotic, have in common. [2]

• Cue. Any two of: a cell membrane, cytoplasm, ribosomes, DNA.

Q2. Name the three structures found in plant cells but not in animal cells, and give the function of each. [3]

• Cue. Cell wall (support and shape), chloroplasts (photosynthesis), large central vacuole (stores water and keeps the cell firm).