Cell Biology and Origin of Life Review Flashcards

Vocabulary practice flashcards covering cell theory, origin of life theories, eukaryotic organelles, cellular transport types, and microscope types/parts.

Cell Theory

A central biological concept stating that all living things are composed of cells, the cell is the basic unit of structure and function in living organisms, and all cells come from pre-existing cells.

Abiogenesis Theory

The hypothesis that life can arise spontaneously from non-living or inorganic matter.

Biogenesis Theory

The principle that living organisms can only arise from pre-existing living organisms.

Endosymbiotic Theory

The evolutionary theory describing how eukaryotic cells developed from symbiotic relationships between distinct prokaryotic organisms.

RNA World

The hypothesis that early self-replicating life forms relied on RNA as genetic material before the evolution of DNA and proteins.

Nucleus

A double-membrane organelle that serves as the cell control center and houses double-stranded DNA and genes.

Ribosomes

Cellular structures composed of two subunits made of RNA that perform protein synthesis.

Endoplasmic Reticulum

A membrane system of folded sacs involved in protein synthesis and intracellular transport.

Lysosome

A membrane-bound sac that breaks down excess or waste substances within the cell.

Mitochondrion

A bean-shaped, double-membrane organelle that produces cellular energy in the form of ATP.

Golgi Apparatus

A stack of tubular membranes that modifies, sorts, and packages proteins.

Nucleolus

A dark, dense region inside the nucleus responsible for producing and assembling ribosomes.

Cytoplasm

A thick, jelly-like fluid inside the cell that transmits chemical signals and holds organelles in place.

Cell Membrane

A flexible, thin phospholipid layer that regulates the movement of molecules into and out of the cell.

Cell Wall

A rigid outer fibrous layer made of cellulose that provides structural protection and support to plant cells.

Cytoskeleton

A network of protein fibers that supports cell movement and maintains cell shape.

Chloroplast

A double-membrane organelle with internal stacks that captures light energy and converts it into glucose.

Vacuole

A membrane-bound sac that temporarily stores materials like water, nutrients, and sugars, while maintaining turgor pressure in plant cells.

Facilitated Diffusion

A form of passive transport where large molecules move down their concentration gradient through membrane transport proteins without requiring ATP.

Hypotonic Solution

A solution with a lower solute concentration (higher water concentration) relative to the interior of a cell, causing water to flow inside and make the cell swell.

Stereo (Dissecting) Microscope

A microscope that provides low magnification to create a 3D high-detail surface view of large specimens.

Compound Light Microscope

A microscope providing medium-to-high magnification for thin specimens, limited in resolution by the wavelength of light.

Scanning Electron Microscope (SEM)

A high-powered electron microscope that provides 3D high-resolution surface images of dead specimens.

Transmission Electron Microscope (TEM)

An electron microscope that passes beams through ultra-thin slices of dead specimens to produce 2D high-resolution images of internal structures.