Cell Structure and Function Quiz

Cell Theory

• All living organisms are composed of one or more cells.
• Cells are the basic units of structure and function in all organisms.
• All cells come from previously existing cells.
• The activity of an entire organism depends on the total activity of its independent cells.

Organelles

• Organelles are structures within a cell that work together for cell function.
• They are like organs in the human body, each with a specific function.
• Most organelles are membrane-bound, controlling what enters and exits.

Important Cellular Structures (not organelles)

• Cytoplasm: Jelly-like substance containing organelles. Provides structural support.
• Chromatin: Uncoiled DNA in the nucleus; provides instructions for cell life and replication.
• Ribosomes: Produce proteins (used for muscle and structure). Located in the cytoplasm or attached to the rough ER.

Organelles Found in Plant and Animal Cells

• Cell Membrane: Encloses the cell's contents and controls what enters/exits. Selectively permeable.
• Nucleus: Protects and holds genetic material (DNA) and the nucleolus. Double-layered membrane.
• Nuclear Membrane: Double-layered membrane surrounding the nucleus.
• Nucleolus: Non-membrane-bound structure in the nucleus that produces ribosomes.
• Endoplasmic Reticulum (ER): Network of folded membranes, involved in transporting materials.
• Rough ER: Has ribosomes, involved in protein synthesis.
• Smooth ER: Produces lipids and steroids.
• Golgi Bodies: Stacked organelles that package and transfer materials in/out of the cell.
• Mitochondria: "Powerhouse of the cell"; creates energy by breaking down glucose. Double-membrane structure. Contains its own genetic material in animal cells.
• Vacuoles: Fluid-filled sacs for storage and digestion. Provides turgor pressure in plant cells.

Organelles Found in Animal Cells Only

• Lysosomes: Digest and recycle cellular material. Important for waste removal.
• Centrioles: Involved in cell division.

Organelles Found in Plant Cells Only

• Cell Wall: Rigid outer layer providing support and structure. Made of cellulose.
• Chloroplast: Contains chlorophyll for photosynthesis. Found near the cell's edges. Contains its own genetic material.

Cell Classification

• Eukaryotic Cells: Contain a nucleus.
• Prokaryotic Cells: Do not contain a nucleus; genetic material floats in the cytoplasm (e.g., bacteria).

Cell Division

• Cell division occurs for repair, growth, and reproduction.
• The cell cycle involves interphase (longest phase, cell functions, DNA replicates), mitosis (division of genetic material) and cytokinesis (division of cell contents).
• Mitosis (4 phases): Prophase, Metaphase, Anaphase, and Telophase.
• Cell division produces 2 daughter cells.
• Cell cycle checkpoints ensure proper cell function and division.

Cancer

• Cancer is uncontrolled cell growth and division.
• Characterized by: Uncontrolled growth, failure of checkpoints, failure of apoptosis - cell death.
• Two types:
• Benign: Non-cancerous, can disrupt surrounding cells.
• Malignant: Cancerous, destroys/disrupts nearby tissue. Potential for metastasis (spread).
• Diagnosing cancer may involve imaging techniques such as X-rays, CT scans, ultrasounds, and endoscopy.

Specialized Cells and Differentiation

• Specialized cells have unique characteristics for specific functions.
• Cellular differentiation is the process where cells become specialized.
• Stem cells: Undifferentiated cells that can become specialized cell types.
• Embryonic stem cells: Found in embryos; can differentiate into any cell type.
• Tissue stem cells: Found in tissues; can differentiate into a limited number of cell types.

Cellular Hierarchy

• Organisms with complex structures are comprised of organized cells, tissues, organs, organ systems and the organism itself.

Tissues

• Epithelial tissue: Lines body surfaces and cavities; provides protection.
• Connective tissue: Supports, insulates, and connects; includes bone, ligament, cartilage, and blood.
• Muscle tissue: Responsible for movement.
• Nerve tissue: Conducts electrical impulses for communication.

Digestive System

• Includes mouth, esophagus, stomach, small intestine, large intestine, liver, pancreas, and gallbladder.
• Function: breaks down food, absorbs nutrients, eliminates waste.
• Disorders: Heartburn, ulcers,

Circulatory System

• Transports oxygen, nutrients, and waste throughout the body.
• Consists of heart, blood vessels, and blood.
• Blood types (e.g., A, B, AB, O).
• Components: red blood cells, white blood cells, platelets, and plasma.
• Diseases: Coronary artery disease, heart attack.

Musculoskeletal System

• Bones and muscles for support and movement.
• Structures: bones providing support and structure, muscles providing force.
• Function: movement (muscles pulling on joints). Support(bones)
• Disorders: osteoporosis.

Nervous System

• Communication network that receives and delivers messages.
• Includes brain and spinal cord (central nervous system) and nerves (peripheral nervous system).
• Function: movement, thoughts, and reactions.
• Disorders: multiple sclerosis, concussions.

Respiratory System

• Lungs bring oxygen into the body and removes waste products from the body.
• Mechanism of breathing: inhaling (diaphragm contracts) and exhaling (diaphragm relaxes).
• Gas exchange (oxygen to blood, carbon dioxide from blood).
• Disorders: pneumonia, bronchiolitis, Tuberculosis (TB).

Other Systems (brief overview)

• Endocrine: Hormones.
• Excretory: Waste removal.
• Integumentary: Skin, hair, nails.
• Lymphatic & Immune: Immunity.
• Reproductive: Reproduction.