Cells, Cell Theory, Microscopes, and Cell Organelles

Comprehensive vocabulary flashcards covering the cell theory, historical contributors, characteristics of living organisms (MR. GREEN), microscope mechanics, and plant versus animal cell organelles.

Cell

The basic unit of life and the smallest entity capable of carrying out the functions of life.

Robert Hooke

English scientist who discovered cells in $1665$ while examining a thin slice of cork under a microscope, describing them as tiny boxes or a honeycomb.

Anton van Leuwenhoek

Dutch scientist who invented a magnifying device and built microscopes capable of magnifying objects up to $300\text{ times}$; in $1673$, he observed pond scum, discovered unicellular organisms, and observed blood and bacteria cells.

Animalcules

The term given by Anton van Leuwenhoek to the microscopic single-celled organisms he observed living in pond scum.

Matthias Schleiden

German botanist who concluded in $1838$ that all plant parts are composed of cells.

Theodor Schwann

German physiologist who concluded in $1839$ that all animal tissues are composed of cells.

Rudolf Virchow

German physician who concluded in $1858$ that cells must arise from pre-existing cells following his extensive studies of cellular pathology.

The Cell Theory

A foundational biological concept consisting of three postulates: 1) the cell is the basic unit of life, 2) all cells come from pre-existing cells, and 3) all living things are composed of one or more cells.

MR. GREEN

An acronym representing the seven characteristics that classify living things: Movement, Reproduction, Growth, Response, Excretion, Exchange of Gas, and Nutrition.

Movement (MR. GREEN)

The characteristic of living organisms describing their ability to bend, sway, or relocate.

Reproduction (MR. GREEN)

The characteristic of living organisms describing their ability to proliferate and pass on their traits.

Growth (MR. GREEN)

The characteristic of living organisms describing their ability to increase in size through cell growth or cell division.

Response (MR. GREEN)

The characteristic of living organisms describing their ability to react to a stimulus.

Excretion (MR. GREEN)

The characteristic of living organisms describing their ability to get rid of waste.

Exchange of Gas (MR. GREEN)

The ability in animals to take in oxygen and breathe out carbon dioxide, and in plants to take in carbon dioxide and release oxygen.

Nutrition (MR. GREEN)

The characteristic of living organisms describing their ability to acquire and process food and nutrients.

Microscope

An optical instrument designed to magnify small objects to make them appear larger.

Magnification

The ability or process of making an object appear larger by enlarging its physical appearance.

Resolution

The ability of a microscope to distinguish the individual parts and fine details of an object clearly.

Compound Light Microscope

A microscope that utilizes light focused through several different lenses to produce an enlarged, detailed image of a specimen.

Organelle

A small internal structure inside a cell that carries out a specialized function required to meet the cell's basic survival needs.

Nucleus

A large, dark, and round organelle that acts like a brain or computer hard drive by directing the cell's activities, controlling growth, and containing chromosomes.

Chromosomes

Genetic material contained inside the nucleus that directs cellular growth and reproduction.

Cell Membrane

The outer boundary layer that surrounds and protects the organelles while regulating the movement of materials into and out of the cell.

Cytoplasm

A jellylike fluid surrounding the nucleus and organelles that distributes essential materials, such as food and oxygen, throughout the cell.

Vacuole

A sac-like storage organelle in the cytoplasm holding surplus food, wastes, and substances not immediately needed; plants possess one large vacuole, whereas animals have several smaller ones.

Endoplasmic Reticulum

A folded membrane organelle that produces proteins and transports materials (such as oxygen, food, and water) to different organelles or to the cell exterior.

Mitochondria

Oval-shaped organelles known as the powerhouse of the cell, which break down food particles to release stored energy for the cell to use.

Ribosomes

Tiny organelles distributed abundantly throughout the cytoplasm that function to manufacture proteins.

Golgi Apparatus

A folded organelle produced by the endoplasmic reticulum that packages and delivers proteins to the rest of the cell.

Lysosomes

Organelles found exclusively in animal cells that break down food, digest wastes, and help destroy viruses and bacteria.

Cell Wall

A thick, rigid outer boundary composed of cellulose found only in plants and fungi that provides structural support and allows materials to pass through.

Chloroplast

An organelle found only in plant cells where photosynthesis occurs, utilizing radiant energy from the Sun to manufacture carbohydrates (sugars).

Chlorophyll

A green pigment contained in folded membranes inside chloroplasts that absorbs light energy for photosynthesis in green plants.

Plant Cell vs. Animal Cell Organelles

Plant cells uniquely contain a cell wall, chloroplasts, and a single large central vacuole, whereas animal cells uniquely contain lysosomes, lack cell walls and chloroplasts, and have multiple small vacuoles.