Cell Theory and Major Sub-Cellular Organelles

A comprehensive set of flashcards covering key vocabulary and concepts related to cell theory and major organelles.

Cell Theory

A set of ideas universally accepted that living things are made up of cells.

Robert Hooke

17th-century scientist who first observed box-shaped structures in cork and coined the term 'cells'.

Matthias Schleiden

Concluded that all plant tissues are composed of cells and that an embryonic plant arises from a single cell.

Theodor Schwann

Founded modern histology by defining the cell as the basic unit of animal structure.

Rudolf Virchow

Described that every cell originates from another existing cell.

Postulate 1 of Cell Theory

All organisms are made up of one or more cells.

Postulate 2 of Cell Theory

The cell is the basic unit of life.

Postulate 3 of Cell Theory

Cells arise from pre-existing cells.

Unicellular Organisms

Organisms made up of a single cell.

Multicellular Organisms

Organisms made up of more than one cell.

Energy Flows Happen Within Cells

One of the additional postulates of modern cell theory.

Heredity Information

Information contained in DNA that is passed from cell to cell.

Virus

A strand of DNA or RNA with a protective shell made from protein; not considered a living thing.

Bacteria

A large domain of prokaryotic microorganisms typically consisting of single biological cells.

Prokaryotic Cells

Unicellular cells without a true nucleus or membrane-bound structures.

Eukaryotic Cells

Cells that are multicellular, have a nucleus and membrane-bound organelles.

Cell Membrane

Controls the movement of materials in and out of cells.

Cytoplasm

The semifluid substance in a cell where chemical processes take place.

Endoplasmic Reticulum (ER)

Network of interconnected sacs and canals; site for protein synthesis.

Golgi Body

Packages protein molecules for secretion and origin of lysosomes.

Lysosomes

Membranous sacs containing enzymes for digestion within a cell.

Mitochondria

Membranous sacs that generate energy for the cell; known as the powerhouse of the cell.

Nucleus

Large membrane-bound organelle containing genetic material in the form of DNA.

Ribosomes

Particles made of protein and RNA; site of protein synthesis.

Vesicles

Membranous sacs involved in transport and temporary storage of substances.

Skin Cells

Keratinocytes and melanocytes that make up the skin; keratinocytes produce keratin.

Muscle Cells

Long tubular cells that assist in movement of limbs and organs.

Blood Cells

Red blood cells transport oxygen; white blood cells defend against pathogens.

Fat Cells

Adipocytes or lipocytes that store fats and act as energy reserves.

Nerve Cells

Neurons that carry messages to different parts of the body.

Epithelial Tissue

Covers body surfaces, lines body cavities, and may secrete glands.

Connective Tissue

Binds and supports body parts.

Muscular Tissue

Facilitates movement of body parts.

Nervous Tissue

Processes and transmits information throughout the body.

Squamous Epithelium

Flat and thin cells found in skin and lining of cavities.

Columnar Epithelium

Cylindrical cells facilitating nutrient movement in the stomach and intestines.

Ciliated Epithelium

Columnar cells with hair-like projections that move mucus in the respiratory tract.

Blood

Fluid connective tissue transporting oxygen, nutrients, and hormones through blood vessels.

Bone

Connective tissue composed of cells embedded in a matrix of calcium and phosphorus.

Fibrous Connective Tissue

Includes tendons connecting muscles to bones and ligaments connecting bones.

Cartilage

Flexible connective tissue providing support in nose, ears, and joints.

Adipose Connective Tissue

Storage for fats and lipids; provides insulation.

Striated Muscle

Voluntary muscle with striations found in limbs and body trunk.

Unstriated Muscle

Involuntary muscle without striations found in organs.

Cardiac Muscle

Involuntary muscle that contracts to pump blood; found in the heart.

Neuron

Nerve cell that processes and transmits information.

Glial Cell

Surrounds and supports neurons, provides nutrients, and maintains homeostasis.

Sperm Cells

Sex cells specialized for reproduction with a flagellum for motility.

Ovum Cells

Female reproductive cells larger than sperm and covered with protective layers.

Red Blood Cells

Transport oxygen and carbon dioxide; have a bi-concave shape for efficiency.

White Blood Cells

Identify and destroy pathogens; possess granules for engulfing bacteria.

Microvilli

Finger-like projections in intestinal cells that increase absorptive capacity.

Plant Cell

Multicellular eukaryotic life forms with rigid cell walls and conducting functions.

Parenchyma Cells

Thin-walled cells in non-woody plant parts involved in metabolism.

Collenchyma Cells

Supportive plant cells with thickened walls found in growing shoots.

Sclerenchyma Cells

Rigid plant cells that provide support, composed of cellulose and lignin.

Meristematic Cells

Plant cells that divide to contribute to growth; found at root and shoot apices.

Xylem

Vascular tissue that transports water and nutrients from roots to parts of the plant.

Phloem

Vascular tissue that carries carbohydrates to plant parts where needed.

Dermal Tissue

Protective outer layer of plants, comparable to skin.

Guard Cells

Control the opening and closing of stomata in leaves.

Root Hairs

Increase surface area of roots for better water absorption.

Palisade Cells

Photosynthetic cells containing chloroplasts and chlorophyll.