General Biology 1 - Reviewer: Microscope, Cell Theory, and Cell Structures

Vocabulary flashcards covering the history and parts of the microscope, the development of cell theory, and the structures, functions, and modifications of prokaryotic and eukaryotic cells.

Microscope

A scientific instrument used to make very small objects appear larger by using lenses to magnify and enlarge images of objects like cells and microorganisms.

Zacharias Janssen

A Dutch spectacle maker credited with the invention of the microscope in the late 16th century along with his father.

Antonie van Leeuwenhoek

Known as the "Father of Microbiology," he improved microscope lenses and was the first person to observe living cells, including bacteria and protozoa.

Eyepiece (Ocular Lens)

The lens at the top of the microscope that the user looks through, which further magnifies the image formed by the objective lens, usually by $10\times$.

Body Tube

The part that connects the eyepiece to the objective lenses and maintains the correct distance between them.

Arm

The part of the microscope that supports the body tube, connects it to the base, and is used for safely carrying the instrument.

Revolving Nosepiece

The rotating part of the microscope that holds the objective lenses and allows for switching between different magnifications.

Objective Lenses

Lenses mounted on the nosepiece, commonly found in magnifications of $4\times$, $10\times$, and $40\times$, that magnify the specimen.

Stage

The flat platform where the microscope slide is placed for viewing.

Stage Clips

The components used to hold the microscope slide securely in place on the stage.

Diaphragm (Iris Diaphragm)

The mechanism that controls the amount of light passing through the specimen.

Light Source (Illuminator)

Provides the light that passes up through the specimen and the lenses.

Condenser

Focuses light onto the specimen to provide a clearer image.

Coarse Adjustment Knob

The knob used for initial, large focusing movements to bring the specimen roughly into focus.

Fine Adjustment Knob

The knob used for small, precise focusing adjustments to sharpen the image of the specimen.

Base

The bottom part of the microscope that provides support and stabilizes the entire instrument.

Robert Hooke

A scientist who in 1665 observed cork and named the tiny compartments "cells" after the Latin word "cellula," meaning small room.

Robert Brown

A scientist who in 1833 identified and named the nucleus as a constant component within plant cells.

Matthias Schleiden

A botanist who in 1838 concluded that all plants are composed of cells.

Theodor Schwann

A zoologist who in 1839 concluded that all animals are made of cells and proposed the cell as the basic unit of all living things.

Rudolf Virchow

A scientist who in 1855 proposed that all cells arise only from pre-existing cells, refuting the idea of spontaneous generation.

Cell Theory Postulates

1. All living organisms are composed of one or more cells. 2. The cell is the basic unit of structure and function. 3. All cells arise from pre-existing cells.

Prokaryotic Cells

Simple, usually unicellular organisms that lack a true nucleus (DNA is in the nucleoid) and membrane-bound organelles; they reproduce via binary fission.

Eukaryotic Cells

Complex cells that contain a true nucleus enclosing linear DNA and various membrane-bound organelles; they reproduce through mitosis or meiosis.

Binary Fission

A form of asexual reproduction in prokaryotes where the cell replicates its DNA, elongates, forms a septum, and divides into two genetically identical daughter cells.

Nucleus

A membrane-bound organelle that contains genetic material (DNA) and controls the cell's activities.

Nucleolus

A structure within the nucleus responsible for producing ribosomal RNA (rRNA) for ribosome production.

Rough Endoplasmic Reticulum (RER)

A network of membranes that makes and transports proteins within the cell.

Smooth Endoplasmic Reticulum (SER)

A network of membranes involved in making lipids and detoxifying harmful substances.

Ribosomes

Small, non-membrane-bound structures that synthesize proteins needed for growth, repair, and cell functions.

Golgi Apparatus

A series of flattened sacs that modifies, packages, stores, and transports materials using vesicles.

Lysosome

An organelle containing digestive enzymes that breaks down waste and old cell parts, acting as the cell's "recycling center."

Mitochondrion

The "powerhouse of the cell" which produces $ATP$ (adenosine triphosphate) through energy transformation and contains its own DNA.

Chloroplast

A double-membrane plastid containing chlorophyll used by plant cells to absorb sunlight for photosynthesis.

Chromoplast

A plastid that produces and stores pigments, providing the red, orange, and yellow colors seen in fruits and flowers.

Leucoplast

A colorless plastid that stores food materials; includes amyloplasts (starch), elaioplasts (oils), and aleuroplasts (proteins).

Cytoskeleton

A network of protein filaments (microtubules, microfilaments, intermediate filaments) that maintains cell shape and provides structural support.

Plasma (Cell) Membrane

A thin, flexible outer covering that controls the entry and exit of materials while maintaining a stable internal environment.

Cell Wall

A rigid outer layer in plant cells that provides support, protection, and prevents the cell from bursting when water enters.

Mitochondrial Myopathy

A disease caused by defects in the mitochondria, leading to muscle weakness due to low energy production.

Tay-Sachs Disease

A condition caused by lysosome defects where waste substances build up in nerve cells.

Cilia

Short, numerous hair-like projections that move together to transport substances across a cell surface or move the cell itself.

Microvilli

Short, finger-like projections that increase a cell's surface area to improve the efficiency of nutrient absorption.

Flagellum

A long, whip-like projection that uses wave-like motions to propel a cell through liquids.

Cell-to-Cell Junctions

Specialized structures including tight junctions (leakage prevention), gap junctions (communication), and adhesion junctions (holding cells together).