Unit 1 Science Test - MEGA Study Guide PDF

MEGA STUDY GUIDE: Unit 1 Science Test Test Date: October 9th --- Table of Contents 1. Characteristics of Life 2. The Cell Theory 3. Abiotic vs. Biotic Factors 4. Cell Types (Prokaryotic vs. Eukaryotic) 5. Cell Organelles 6. Cell Processes 7. Levels of Organization...

MEGA STUDY GUIDE: Unit 1 Science Test Test Date: October 9th --- Table of Contents 1. Characteristics of Life 2. The Cell Theory 3. Abiotic vs. Biotic Factors 4. Cell Types (Prokaryotic vs. Eukaryotic) 5. Cell Organelles 6. Cell Processes 7. Levels of Organization 8. Tissues and Body Systems --- 1. Characteristics of Life Living organisms share these 8 characteristics: - Made of cells: Either unicellular or multicellular. - Growth and development: Increase in size and complexity. - Reproduction: Sexual or asexual. - Energy use: Autotrophs (make their own food) vs. heterotrophs (consume food). - Response to stimuli: React to environmental changes (e.g., a plant bending towards light). - Homeostasis: Maintain stable internal conditions (e.g., sweating to cool down). - Genetic code (DNA): Passed down to offspring. - Adaptation: Evolve over time. --- 2. The Cell Theory The three core ideas of the Cell Theory: - All living things are made of cells. - Cells are the basic unit of structure and function in organisms. - All cells come from pre-existing cells. --- 3. Abiotic vs. Biotic Factors - Biotic: Living things (e.g., animals, plants, bacteria). - Abiotic: Non-living things (e.g., water, sunlight, rock). --- 4. Cell Types (Prokaryotic vs. Eukaryotic) Prokaryotic Cells: Lack a true nucleus: Their DNA floats freely in the cytoplasm (not enclosed in a membrane). No membrane-bound organelles: They have ribosomes but lack structures like mitochondria or chloroplasts. Smaller and simpler than eukaryotic cells. Always unicellular: Found in organisms like bacteria and archaea. Example: Bacteria (e.g., Escherichia coli)—single-celled organisms that can live in various environments, including the human gut. Eukaryotic Cells: Have a true nucleus: Their DNA is enclosed within a nuclear membrane. Contain membrane-bound organelles: Includes mitochondria, chloroplasts (in plants), the endoplasmic reticulum, and the Golgi apparatus. Larger and more complex: Eukaryotic cells make up multicellular organisms, such as animals and plants, but can also be unicellular (e.g., protists). Can be multicellular or unicellular: For example, humans are made of trillions of eukaryotic cells, while amoebas are single-celled eukaryotes. --- 5. Cell Organelles - Nucleus: Control center, holds DNA. - Mitochondria: Powerhouse, converts food into energy (ATP). - Chloroplasts: Found in plants, used in photosynthesis. - Ribosomes: Make proteins. - Cell membrane: Controls what enters/exits the cell. - Cell wall: Provides structure (plants). - Vacuole: Stores water and nutrients. --- 6. Cell Processes - Diffusion: Movement of molecules from high to low concentration. - Osmosis: Diffusion of water. - Photosynthesis: Plants use sunlight to make glucose. - Equation: 6CO2 + 6H2O → C6H12O6 + 6O2 - Cellular Respiration: Cells break down glucose for energy. - Equation: C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP --- 7. Levels of Organization - Cells → Tissues → Organs → Organ Systems → Organism Example: Lung cell → Lung tissue → Lung → Respiratory system → Human --- 8. Tissues - Muscle Tissue: Moves the body (skeletal, smooth, cardiac). - Connective Tissue: Provides support (bone, blood). - Nervous Tissue: Transmits signals (brain, spinal cord). 9. Body Systems Circulatory: Transports oxygen and nutrients. ○ Key organs: Heart, blood vessels. Respiratory: Exchanges gases (oxygen in, CO₂ out). ○ Key organs: Lungs, trachea. Digestive: Breaks down food for energy. ○ Key organs: Stomach, intestines. Excretory: Removes waste and maintains water balance. ○ Key organs: Kidneys, bladder. Nervous: Controls body responses.  ○ Key organs: Brain, spinal cord. Muscular: Allows movement. ○ Key organs: Skeletal muscles. Skeletal: Provides structure and support. ○ Key organs: Bones, joints. Endocrine: Regulates body functions with hormones. ○ Key organs: Glands. Immune/Lymphatic: Defends against pathogens. ○ Key organs: Lymph nodes, spleen. Reproductive: Produces offspring. ○ Key organs: Ovaries, testes.