Revise: Cell Structure and Organization
Explore what animal and plant cells are built from, how microscopes reveal them, and how specialized cells build up into tissues, organs, and organ systems.
All living things are made of cells; all cells come from existing cells.
A microorganism made of dividing cells is classified as living.
Prokaryotic cells (bacteria) have no nucleus; eukaryotic cells do.
No nucleus, ~1 ΞΌm wide β prokaryotic.
The nucleus stores DNA and controls the cell.
Remove the nucleus β the cell can no longer divide.
Plant cells add a cell wall, chloroplasts, and a large vacuole.
Rigid shape + green structures + fluid sac β plant cell.
Magnification = Image size / Actual size (same units).
60 mm image, 0.02 mm actual β Γ3000.
All living things are made of cells, and all cells come from pre-existing cells.
No spontaneous generation of cells.
Prokaryotic = no nucleus, small. Eukaryotic = has a nucleus, larger.
Bacteria are prokaryotic; animal/plant cells are eukaryotic.
The cell membrane controls what enters/leaves; cytoplasm fills the cell.
Cucumber in salt water loses water across its membranes.
The nucleus stores DNA and directs the cell.
Red blood cells have no nucleus and cannot divide.
Mitochondria release energy; ribosomes build proteins.
Muscle cells have more mitochondria than skin cells.
ER transports materials; Golgi processes and packages them.
Ribosome β ER β Golgi β cell membrane for a secreted protein.
Cell wall (support), vacuole (water storage), chloroplasts (photosynthesis).
A wilted plant perks up as its vacuoles refill with water.
Shared: nucleus, membrane, mitochondria, ribosomes. Plant-only: wall, chloroplasts, big vacuole.
Cheek cells (animal) vs. onion cells (plant) under a microscope.
Magnification = Image size / Actual size β convert units first.
2.5 mm image, 25 ΞΌm (0.025 mm) actual β Γ100.
Cell β tissue β organ β organ system.
Muscle cells β muscle tissue β the heart (organ) β circulatory system.