14.1 Cell Theory & Microscopes

Cell Theory

• All living organisms are made of cells, cells are the basic units of life, and all cells come from pre-existing cells.

• All living organisms are made of tissues, tissues are the basic units of life, and all tissues come from pre-existing tissues.

• All living organisms are made of organs, organs are the basic units of life, and all organs come from pre-existing organs.

• All living organisms are made of molecules, molecules are the basic units of life, and all molecules come from pre-existing molecules.

Cell Membrane

• A rigid structure that protects the cell from external damage.

• A flexible, semi-permeable barrier made of a lipid bilayer that surrounds the cell, controlling what enters and exits while maintaining homeostasis.

• A solid wall that provides support and structure to the cell.

• A network of proteins that facilitates communication between cells.

Light Compound Microscope

• A microscope that uses visible light and multiple lenses to magnify thin specimens up to about 1000x. Ideal for viewing cells and tissues.

• A type of microscope that uses electron beams to achieve high magnification.

• A device that uses ultraviolet light to visualize fluorescent specimens.

• A simple magnifying glass that can only enlarge objects up to 10x.

Eukaryotic Cell

• A cell that has a true nucleus enclosed by a membrane and other membrane-bound organelles like mitochondria and the Golgi apparatus.

• A simple cell without a nucleus, such as bacteria.

• A cell that can only be found in multicellular organisms.

• A cell that has a rigid cell wall and lacks membrane-bound organelles.

Scientific Law

• A statement that describes a consistent natural phenomenon, often expressed mathematically (e.g., Newton’s laws).

• A hypothesis that has not yet been tested.

• An observation that cannot be replicated.

• A theory that explains a wide range of phenomena.

Prokaryotic Cell

• A complex, multi-celled organism with a nucleus.

• A simple, single-celled organism that lacks a nucleus and membrane-bound organelles.

• An organism that has membrane-bound organelles but no cell wall.

• A type of virus that can infect both prokaryotic and eukaryotic cells.

Nucleus

• The powerhouse of the cell that produces energy.

• The control center of a eukaryotic cell that contains DNA and regulates cell activities like growth, metabolism, and reproduction.

• The structure that provides support and shape to the cell.

• The site of protein synthesis in the cell.

Scanning Electron Microscope (SEM)

• A microscope that uses a beam of light to magnify specimens.

• A microscope that uses a beam of electrons to scan the surface of a specimen up to about 1,000,000x, producing detailed 3D images of its texture and structure.

• A type of microscope that only observes live specimens under natural light.

• A device used to measure the temperature of a specimen's surface.

Repetition

• Performing an experiment multiple times to ensure consistent results and reduce errors. Repeated trials.

• Conducting a single trial to gather data.

• Analyzing data from previous experiments without conducting new trials.

• Changing variables in an experiment to test different outcomes.

Replication

• The process of repeating an experiment or study to verify its results and confirm that the findings are reliable and not due to random chance or error.

• A method of collecting data through surveys and interviews.

• The act of publishing research findings in a scientific journal.

• A technique used to analyze the statistical significance of data.