Bio Vocab

Scientific Process

1. Spontaneous generation: The outdated idea that living organisms arise from nonliving matter.

2. Manipulated variable: The variable intentionally changed in an experiment.

3. Responding variable: The variable that is observed or measured in response to changes in the manipulated variable.

4. Controlled variable: Variables kept constant to ensure a fair test.

5. Experimental control: A standard for comparison to assess the effect of the manipulated variable.

Cell Structures & Functions

6. Electron microscopy: A technique for imaging small structures using electrons instead of light.

7. Open system: A system that exchanges matter and energy with its surroundings.

8. Organelles: Specialized structures in cells that perform specific functions.

9. Cell membrane: The semi-permeable barrier enclosing a cell.

10. Nucleus: The organelle that contains genetic material (DNA).

11. Cytoplasm: Jelly-like substance inside the cell where organelles are suspended.

12. Chloroplasts: Organelles in plant cells where photosynthesis occurs.

13. Photosynthesis: Process by which plants convert sunlight into chemical energy.

14. Vacuoles/vesicles: Membrane-bound sacs for storage and transport.

15. Turgor pressure: Pressure exerted by water inside the cell against the cell wall.

16. Turgid: Swollen due to high water content.

Transport Processes

17. Diffusion: Movement of molecules from high to low concentration.

18. Rate of diffusion: Speed at which molecules spread.

19. Facilitated diffusion: Passive transport aided by proteins.

20. Solvent: A substance (e.g., water) that dissolves another substance.

21. Solute: Substance dissolved in a solvent.

22. Concentration gradient: Difference in solute concentration across a membrane.

23. Passive transport: Movement of substances without energy input.

24. Selectively permeable: A property of membranes that allow some substances to pass while blocking others.

25. Semi-permeable: Similar to selectively permeable; lets certain molecules through.

26. Osmosis: Diffusion of water across a semi-permeable membrane.

27. Hypertonic: Solution with a higher solute concentration than the cell.

28. Hypotonic: Solution with a lower solute concentration than the cell.

29. Isotonic: Solution with equal solute concentration to the cell.

30. Channel proteins: Proteins that provide pathways for specific substances.

31. Carrier proteins: Proteins that transport substances across membranes.

32. Active transport: Movement of substances against a gradient using energy.

33. ATP (Adenosine Triphosphate): The energy currency of the cell.

34. Endocytosis: Process by which a cell engulfs material into a vesicle.

35. Exocytosis: Process by which a cell releases material in vesicles.

Cellular Components

36. Ribosomes: Sites of protein synthesis.

37. Lysosomes: Organelles containing enzymes to break down waste.

38. Golgi apparatus: Organelles that modify, sort, and package proteins and lipids.

39. Mitochondria: Powerhouse of the cell; site of energy production (cellular respiration).

40. Cytoskeleton: Network of fibers providing structural support.

41. Liposomes: Spherical vesicles used in drug delivery.

42. Chlorophyll: Green pigment involved in photosynthesis.

43. Phospholipid bilayer: Structure forming the cell membrane.

44. Fluid mosaic model: Describes the dynamic nature of cell membranes.

Part 1: Contributions to Cellular Biology

1. Ancient Greeks: Proposed early theories about the origins of life, including concepts of spontaneous generation.

2. Hans and Zacharias Janssen: Invented the first compound microscope.

3. Robert Hooke: Coined the term "cell" after observing cork under a microscope.

4. Anton van Leeuwenhoek: Discovered microorganisms using his refined microscopes.

5. Louis Pasteur: Disproved spontaneous generation and developed pasteurization.

6. Robert Brown: Identified the nucleus in cells.

7. Schleiden, Schwann, and Virchow: Developed cell theory, stating:

   • All living things are made of cells.

   • The cell is the basic unit of life.

   • All cells arise from pre-existing cells.

Here are detailed answers to the questions from Part 2: Cellular Biology and Part 3: Plants:

Part 2: Cellular Biology

1. Name the points of the cell theory:
   
   

   • All living organisms are composed of one or more cells.

   • The cell is the basic unit of structure and function in living organisms.

   • All cells arise from pre-existing cells.

2. Draw and label both a plant and animal cell:
   
   

   • A plant cell has a cell wall, chloroplasts, and a large central vacuole in addition to organelles found in an animal cell.

   • An animal cell lacks a cell wall and chloroplasts but has lysosomes and smaller vacuoles.

3. Describe 2 similarities between the plant and animal cell:
   
   

   • Both have a nucleus containing DNA.

   • Both have organelles like mitochondria, endoplasmic reticulum, Golgi apparatus, and a cell membrane.

4. Describe 6 differences between the plant and animal cell:
   
   

   • Plant cells have a cell wall; animal cells do not.

   • Plant cells have chloroplasts; animal cells do not.

   • Plant cells have a large central vacuole; animal cells have smaller, temporary vacuoles.

   • Animal cells have lysosomes; plant cells generally do not.

   • Plant cells are rectangular; animal cells are rounder.

   • Animal cells rely on centrioles for cell division; plant cells do not.

5. Draw and describe the fluid mosaic model:
   
   

   • The fluid mosaic model depicts the cell membrane as a dynamic structure with a phospholipid bilayer. Proteins, cholesterol, and carbohydrates are embedded within, allowing for fluidity and selective permeability.

6. What is meant by a system, and how is a cell an open system?
   
   

   • A system is a group of interacting components that work together.

   • A cell is an open system because it exchanges materials and energy with its environment (e.g., nutrients enter, waste exits).

7. What is the particle model of matter?
   
   

   • The particle model states that all matter is made up of tiny particles that are in constant motion and are held together by forces.

8. Describe the difference between diffusion, osmosis, facilitated diffusion, active transport, endocytosis, and exocytosis:
   
   

   • Diffusion: Movement of molecules from high to low concentration.

   • Osmosis: Diffusion of water across a semi-permeable membrane.

   • Facilitated diffusion: Passive transport of molecules via proteins.

   • Active transport: Movement of substances against a concentration gradient using energy (ATP).

   • Endocytosis: Cell engulfs materials into a vesicle.

   • Exocytosis: Cell releases materials via vesicles.

9. What is meant by concentration gradient and equilibrium?
   
   

   • Concentration gradient: Difference in concentration between two areas.

   • Equilibrium: When concentrations are equal in all areas, with no net movement of particles.

10. Predict what happens to cells in three solutions (hypertonic, hypotonic, isotonic):
    
    

• Hypertonic solution (Beaker A): Water leaves the cell; the cell shrinks (plasmolysis).

• Hypotonic solution (Beaker B): Water enters the cell; the cell swells or may burst.

• Isotonic solution (Beaker C): No net water movement; the cell remains unchanged.

11. Steps to calculate surface area-to-volume ratio and explain efficiency:

• Calculate the surface area (length × width × number of sides).

• Calculate the volume (length × width × height).

• Divide surface area by volume.

• Cells with a higher ratio are more efficient at material exchange because they have more surface area relative to their volume.

Part 3: Plants

1. Give 3 advantages to being multicellular:
   
   

   • Specialized cells increase efficiency.

   • Greater size allows for better defense and resource acquisition.

   • Increased complexity supports advanced functions (e.g., movement, reproduction).

2. Describe the parts of the plant that make up the shoot system and root system:
   
   

   • Shoot system: Includes stems, leaves, flowers, and fruits; responsible for photosynthesis and reproduction.

   • Root system: Includes roots; responsible for anchorage, water absorption, and nutrient storage.

3. What is the dermal tissue? Ground tissue? Vascular tissue?
   
   

   • Dermal tissue: Outer covering for protection.

   • Ground tissue: Supports storage, photosynthesis, and structure.

   • Vascular tissue: Includes xylem and phloem for water and nutrient transport.

4. What part of the plant are root hairs part of? What is their purpose?
   
   

   • Root hairs are extensions of root epidermal cells.

   • They increase surface area for water and nutrient absorption.

5. What is the purpose of the cuticle? What tissue type is it part of?
   
   

   • The cuticle is a waxy layer that prevents water loss.

   • It is part of dermal tissue.

6. What are guard cells and stomata?
   
   

   • Guard cells surround stomata (pores) and regulate gas exchange and water loss by opening and closing.

7. How are xylem and phloem specialized?
   
   

   • Xylem: Transports water and minerals; cells are dead at maturity and have thick walls.

   • Phloem: Transports sugars; made of living cells with companion cells.

8. Formulas for photosynthesis and cellular respiration:
   
   

   • Photosynthesis: 6CO2+6H2O+light energy→C6H12O6+6O26CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2

   • Cellular respiration: C6H12O6+6O2→6CO2+6H2O+energy (ATP)C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{energy (ATP)}

9. Two gases exchanged in plants and role of tissues:
   
   

   • Carbon dioxide (in) and oxygen (out).

   • Dermal tissue allows gas exchange through stomata.

   • Ground tissue performs photosynthesis (mesophyll cells).

   • Vascular tissue transports nutrients and water.

10. Differences in plant cell activity in dark and sunlight:
    
    

• Dark: Cellular respiration occurs; no photosynthesis.

• Light: Photosynthesis produces sugars; cellular respiration still occurs.

11. Photosynthesis changes with more CO₂ or increased light intensity:

• More CO₂: Increases photosynthesis until other factors become limiting.

• Increased light intensity: Increases photosynthesis until saturation.

12. Adhesion, cohesion, and root pressure:

• Adhesion: Water molecules stick to surfaces (e.g., xylem walls).

• Cohesion: Water molecules stick to each other.

• Root pressure: Pushes water upward from roots.

13. Plant water transport from roots to leaves:

• Water enters roots through osmosis, moves up xylem via capillary action, root pressure, and transpiration pull.

14. Plant sugar transport:

• Sugars move from leaves (source) to roots and other parts (sink) through phloem via pressure-flow.

15. Plant response to stimuli using phototropism and gravitropism:

• Phototropism: Growth towards light (auxin concentration increases on shaded side).

• Gravitropism: Growth in response to gravity (roots grow downward; shoots grow upward).