Biology Chapter: Characteristics of Organisms

Characteristics of Organisms

• Organisms grow and develop
• Organisms change over time
• Organisms respond to their environment
• Organisms maintain homeostasis (stable internal environment)
• Organisms have a genetic code

Specialized Plant Cells

• Plants exchange gases (CO2, O2, H2O) through tiny openings called stomata

Chemical Energy and ATP

• ATP (adenosine triphosphate) is the basic energy source for all cells
• ATP consists of adenine, ribose, and three phosphate groups

Cellular Respiration and Photosynthesis

• Cellular Respiration: Breaks down glucose to release energy
  • Substages: Glycolysis, Krebs Cycle, Electron Transport Chain
  • Location:
    • Glycolysis: Cytoplasm
    • Krebs Cycle: Matrix of Mitochondria
    • Electron Transport Chain: Membrane of Mitochondria
  • Raw Materials: Oxygen, glucose, water, carbon dioxide
  • Waste Products: Carbon dioxide, water, oxygen
  • Major Products: ATP, sugars
  • Energy Source: Electrons (from glucose oxidation)
• Photosynthesis: Uses sunlight to convert carbon dioxide and water into glucose
  • Substages: Light-dependent, Light-independent
  • Location:
    • Light-dependent: Thylakoids
    • Light-independent: Stroma
  • Raw Materials: Carbon dioxide, water, sunlight
  • Waste Products: Oxygen
  • Major Products: Glucose, ATP
  • Energy Source: Sunlight

Photosynthesis Experiments

• Van Helmont: Plant mass increase comes mainly from water
• Priestley: Plants release oxygen
• Jan Ingenhousz: Light is needed for plant oxygen production

Definitions

• Homeostasis: Regulation of a stable internal environment (e.g., temperature, glucose levels)
• Autotrophs: Organisms that make their own food (e.g., plants)
• Heterotrophs: Organisms that consume other organisms (e.g., animals)
• Cell Specialization: Different cells develop to perform specific tasks
• Cell Culture: Growing cells outside their natural environment under controlled conditions
• Cell Fractionation: Separating different parts of a cell using a centrifuge
• Intraspecific Competition: Competition between individuals of the same species
• Interspecific Competition: Competition between individuals of different species
• Predation: One organism capturing and consuming another
• Symbiosis: Two species living closely together
  • Mutualism: Both species benefit
  • Commensalism: One species benefits, the other is neither harmed nor helped
  • Parasitism: One species benefits, the other is harmed
• Cell Wall: Rigid outer layer surrounding some cells (plants)
• Cell Membrane: Double layer of lipids and proteins surrounding a cell (plasma membrane)
• Prokaryotes: Cells without a nucleus (e.g., bacteria)
• Eukaryotes: Cells with a nucleus (e.g., plants, animals)
• Diffusion: Movement of particles from high concentration to low concentration
• Osmosis: Movement of water across a selectively permeable membrane
• Hypertonic: Higher solute concentration
• Hypotonic: Lower solute concentration
• Isotonic: Equal solute concentration
• Lactic Fermentation: Anaerobic process converting glucose to cellular energy.

This quiz covers fundamental characteristics of organisms, the structure and function of specialized plant cells, as well as the processes of cellular respiration and photosynthesis. Test your knowledge on how organisms grow, respond to their environment, and convert energy. Ideal for biology students looking to reinforce their understanding of essential concepts.