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Flashcards in 01_Intro to Cell Bio Deck (8)
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1

What are three components of cell theory?

1) All organisms are composed of one or more cells.
2) Cells are the structural units of life.
3) Cells arise from pre-existing cells through the process of cell division.

2

What are the three domains of life? Which are prokaryotes?

Eukaryotes, Archaea, Bacteria; the latter two are prokaryotes.

3

Which came first: eukaryotic cells or prokaryotic cells?

Prokaryotic

4

Describe endosymbiotic theory in 1 sentence.

Prokaryotic cells arose first, and organelles in eukaryotic cells (mitochondria & chloroplasts) evolved from smaller prokaryotic cells.

5

What evidence is there in support of endosymbiotic theory? (6 points)

- Eukaryotic cell organelles (mitochondria & chloroplasts) contain their own DNA.
- Ribosomal RNA sequences in eukaryotes are highly conserved, and resemble that of prokaryotic cells.
- Organelles duplicate independent of the nucleus.
- There is an absence of any intermediary evolutionary step containing eukaryotic cells with organelles.
- Mitochondria/chloroplasts possess a DOUBLE lipid bilayer (inner membrane is prokaryote-like; outer membrane eukaryote-like -- BUT this simplification is controversial)
- There exist many symbiotic relationships between organisms.

6

What is the proposed origin for the mitochondrion, chloroplast, and the "parent" cell?

aerobic bacterium, photosynthetic cyanobacterium, and anaerobic heteretrophic prokaryote (respectively).

7

What is the point of controversy in endosymbiotic theory?

Appearance of the nuclear envelope and the ER

8

How many genes were present in LUCA? What does this suggest?

4133; suggests this ancestor was surprisingly complex