Prokaryotic vs. Eukaryotic Cells

Review flashcards covering the differences, similarities, structures, and examples of prokaryotic and eukaryotic cells based on the lecture notes.

What does the term prokaryotic mean?

It comes from Greek, meaning 'before the nucleus'.

What key cellular structures do prokaryotic cells lack?

A membrane-bound nucleus and other membrane-bound organelles (e.g., mitochondria).

Are prokaryotic cells unicellular or multicellular?

Unicellular.

Where is DNA located in prokaryotic cells?

Freely in the nucleoid region, not enclosed by a membrane.

What are the common shapes of prokaryotic cells?

Coccus (spherical), Bacillus (rod-shaped), and Spiral.

Name three example bacteria listed in the notes.

Staphylococcus aureus, Mycobacterium tuberculosis, and Helicobacter pylori.

List major structural features found in prokaryotic cells.

Plasma membrane, cell wall, cytoplasm, ribosomes, nucleoid region, capsule, pili, flagellum, and sometimes plasmids.

What does the term eukaryotic mean?

From Greek 'true nuclei'; cells with a nucleus enclosed by a nuclear membrane; can be single-celled or multicellular.

What are the defining features of eukaryotic cells?

Nucleus with a nuclear envelope, larger and more complex, membrane-bound organelles, and organized double-stranded DNA; can be uni- or multicellular.

What organisms fall under the category of eukaryotes?

Plants, animals, protists, and fungi.

Name some organelles typically found in eukaryotic cells.

Nucleus, Golgi apparatus, mitochondria, lysosomes, ribosomes; membrane-bound organelles.

How do prokaryotic and eukaryotic cells differ in terms of nuclei?

Prokaryotes lack a true nucleus; eukaryotes have a nucleus enclosed by a nuclear membrane.

How does the genetic material differ between prokaryotes and eukaryotes?

Prokaryotic DNA is circular and located in the cytoplasm (nucleoid); eukaryotic DNA is linear and located in the nucleus.

How do the sizes and complexity compare?

Prokaryotic cells are small and simple; eukaryotic cells are bigger and more complex.

When did prokaryotic and eukaryotic cells first appear?

Prokaryotes appeared about 4 billion years ago; eukaryotes about 1 billion years ago.

What is a plasmid?

A small circular DNA molecule in prokaryotes that can carry accessory genes.

What are pili and capsule in prokaryotes?

Pili are hair-like structures for attachment; the capsule is a protective outer layer outside the cell wall.

Which group is more numerous, prokaryotes or eukaryotes?

Prokaryotes are far more numerous than eukaryotes.

What is the nucleoid region?

The region in prokaryotic cells where DNA resides, not bounded by a membrane.

What is the function of a flagellum?

To enable locomotion (movement).

Name examples of eukaryotic cell shapes mentioned in the notes.

Sperm cell, onion cell, nephron cell.

Do eukaryotic cells always form multicellular organisms?

No; they can be unicellular or multicellular.

What is the difference in DNA organization between prokaryotes and eukaryotes?

Prokaryotes have circular DNA; eukaryotes have linear DNA.

What structures are located in prokaryotes but not in typical eukaryotes?

Nucleoid, plasmid, capsule, and pili are prokaryote-specific features not present in typical eukaryotic cells.