Cells

Good study guide

Animal Cell

Does not have a cell wall or chloroplast; has a small vacuole.

Plant Cell

Contains a cell wall, chloroplasts, and a large vacuole.

Bacteria Cell

Prokaryotic cell that contains no nucleus or membrane-bound organelles.

Prokaryotic Cells

Cells that lack a membrane-enclosed nucleus and organelles, found in domains Bacteria and Archaea.

Eukaryotic Cells

Cells that contain a nucleus and membrane-bound organelles.

Mitochondria

Powerhouse of the cell; site of ATP (energy) production.

Cell Membrane

Thin, flexible barrier around a cell that regulates what enters and leaves.

Nucleus

Large membrane-enclosed structure containing the cell's genetic material (DNA).

Nuclear Membrane

Highly-porous membrane separating the nucleus from the cytoplasm.

Nucleolus

Structure found inside the nucleus that produces ribosomes.

Lysosomes

Organelles in animal cells filled with enzymes to break down materials.

Ribosomes

Make proteins within the cell.

Vacuole

Stores materials such as water, salts, proteins, and carbohydrates.

Endoplasmic Reticulum (ER)

Extensive membranous network composed of rough (ribosome-studded) and smooth (ribosome-free) regions.

Golgi Apparatus

Modifies and packages proteins for export by the cell.

Cytoplasm

Jelly-like fluid inside the cell where organelles are suspended.

Cytoskeleton

Network of fibers that holds the cell together and aids in movement.

Nucleoid

Non-membrane-bounded region in prokaryotic cells where DNA is concentrated.

Plasmid

Small ring of DNA carrying accessory genes separate from the bacterial chromosome.

Plastid

Group of plant organelles used for storage of starches, lipids, or pigments.

Chloroplast

Site where photosynthesis occurs in plant cells.

Cell Wall

Rigid layer of nonliving material surrounding the cells of plants and some other organisms.

Capsule

Sticky layer surrounding the cell walls of some bacteria, providing protection and aiding adhesion.

Pilus

Short, thick hair-like protein structure allowing bacteria to attach to other surfaces.

Flagellum

Long, hair-like structure that enables cell movement.

Mitosis

Part of eukaryotic cell division where the cell nucleus divides.

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms.

Homeostasis

Tendency to maintain a balanced or constant internal state in the body.

Cell Theory

All living things are composed of cells; cells are basic units of structure and function; new cells arise from existing cells.

Redi’s experiment

A study conducted by Francesco Redi in the 17th century to demonstrate that maggots do not spontaneously arise from decaying meat, but rather from eggs laid by flies.

Paseuter’s experiment

An experiment by Louis Pasteur in the 19th century that demonstrated that microorganisms cause fermentation and spoilage, disproving the theory of spontaneous generation.

What are the characteristics of life

The characteristics of life include organization, metabolism, homeostasis, growth, reproduction, response to stimuli, and adaptation through evolution.

How does an organism maintain homeostasis

An organism maintains homeostasis by regulating its internal environment to keep conditions stable despite external changes, using mechanisms like feedback loops and physiological adjustments.

Why is it important to limit variables in an experiment?

Limiting variables in an experiment is crucial to ensure that the results are valid and reliable. It helps isolate the effect of the independent variable on the dependent variable, minimizing the influence of extraneous factors.