Plant Powerhouse

Unit 1: Plant Anatomy • Student Guided Notes Page 1 of 2

Part II: Specialized Tissues & Reproduction Name:

4. Leaf Microscopic Cross-Section (The Food Factory)

Directions: Match each leaf layer to its specialized role by writing the correct letter in the blank.

Leaf Structures

1. Waxy Cuticle

2. Palisade Mesophyll

3. Spongy Mesophyll

4. Vascular Bundle (Vein)

5. Stomata (Pores)

6. Guard Cells

Specialized Functions

A. Contains xylem and phloem to bring water and carry sugar.

B. Waterproof lipid layer preventing water loss from the top.

C. Swell or shrink to open and close the gas exchange pore.

D. Loosely packed cells with air pockets for gas circulation.

E. Tightly packed column cells loaded with chloroplasts for photosynthesis.

F. Microscopic openings on the leaf underside allowing CO₂ in and O₂ out.

5. Flowers, Fruits & Seeds: Plant Perpetuation

🌸 Flower Anatomy

• Petals: Attract _______________
• Stamen (Male): Produces powdery _______________ in the anther.
• Pistil (Female): Includes sticky _______________ and ovary with egg cells.

🌰 Seed Anatomy

• Seed Coat: Outer tough layer that _______________ the inside.
• Embryo: The tiny undeveloped _______________ plant.
• Cotyledon: Stored _______________ supply until germination occurs.

🍎 Fruit Role

• Biological Definition: The ripened _______________ containing seeds.
• Dispersal Strategies: Carried by wind, float in water, or eaten by _______________.

6. Systems Synthesis: What Happens on a Scorching Day?

Imagine an outdoor tomato plant at 2:00 PM on a dry, 98°F afternoon. Explain how the root hairs, xylem, and guard cells collaborate to protect the plant from dying:

1. Guard Cells:

2. Xylem:

3. Root Hairs:

Unit 1: Plant Anatomy • Student Guided Notes Page 2 of 2

1. Why do root cells need oxygen from soil air pockets? What happens to roots when waterlogged?

2. If the roots rot and die, explain why the leaves wilt even though there is plenty of water in the pot:

3. What two specific actions should Maya take immediately to save the plant?

Unit 1: Plant Anatomy • Student Practice Worksheet Page 2 of 2

Master Answer Key & Evaluation Criteria Week 1 Resource Keys

Guided Notes Answer Key

Section 1: Shoot: sunlight, glucose/food; reproduction. Root: soil, minerals, energy/sugars.

Section 2: Taproot: Carrot/Dandelion; deep groundwater. Fibrous: Grass/Corn; topsoil/erosion. Root Hairs: surface.

Section 3 (Table): Xylem: minerals | UP only | Dead | Transpiration pull. Phloem: sucrose/sap | Up and Down | Living.

Section 4 (Leaf Matching): 1-B (Cuticle), 2-E (Palisade), 3-D (Spongy), 4-A (Vein), 5-F (Stomata), 6-C (Guard Cells).

Section 5: Flower: pollinators, pollen, stigma. Seed: protects, baby/young, food/energy. Fruit: ovary, animals.

Plant Architecture Worksheet Answer Key

Part 1 (Matching): 1-C (Xylem), 2-E (Phloem), 3-F (Stomata), 4-A (Guard Cells), 5-B (Root Hairs), 6-D (Cuticle).

Part 2 (Biome Adaptations):

• Cactus: Stem is green to conduct photosynthesis and store massive water reserves; spines reduce surface area to limit transpiration and protect against herbivores; shallow radial roots capture brief rainfall instantly.
• Monstera: Slits allow hurricane winds and light to penetrate to lower leaves without tearing; waxy drip tips shed excess water preventing fungal growth; aerial roots anchor to canopy trees and gather humidity.

Part 3 (Pathway Numbering): Pathway A (Water): 4, 1, 2, 3 (Order: Absorb [1] ➔ Cohesion in xylem [2] ➔ Mesophyll cells [3] ➔ Evaporate out stomata [4]). Pathway B (Sugar): 4, 1, 2, 3 (Order: Synthesized in leaf [1] ➔ Pumped into phloem [2] ➔ Pushed down stem [3] ➔ Stored as starch in roots [4]).

Part 4 (Drowning Houseplant Inquiry):

• 1. Roots require O₂ to generate ATP for cellular respiration and active transport. In stagnant water, anaerobic bacteria rot root tissues.
• 2. Since the root hair cells are dead, they cannot take in water or minerals. Without water entering xylem, leaves dehydrate and wilt.
• 3. Drain standing water immediately; repot in fresh, well-aerated soil with drainage holes; trim away blackened, rotted roots.

Differentiation & Scaffolding Strategies

Support / IEP / ELL:

Provide word banks for Guided Notes. Use color-coded highlighters: blue for xylem/water pathways and orange for phloem/sugar pathways.

Enrichment / Advanced:

Challenge students to research how aphids tap exclusively into phloem tubes without damaging xylem, and how maple syrup harvesting relies on spring phloem pressure.

Unit 1: Plant Anatomy • Teacher Facilitation Guide Page 2 of 2

[A] Waxy Cuticle Layer [B] Upper Epidermis VASCULAR VEIN [E] Xylem [F] Phloem [C] Palisade Layer (Packed Chloroplasts) Air Spaces (Gas Circulation) [D] Spongy Mesophyll [G] Guard Cells Stomatal Pore [G] Guard Cells

Coloring Analysis & Inquiry:

1. Why is the Palisade Layer colored deepest green?

2. What enters and leaves through the yellow Stomata?

Unit 1: Plant Anatomy • Coloring Worksheet Page 2 of 2

Where does a tree's mass come from?

Most people assume giant trees get their physical mass from the soil.

🌲 Reality: Over 95% of a dried tree's solid wood comes directly from carbon in the AIR! Trees are literally built of solidified air and sunlight!

⚖️ 6 Carbon atoms in = 6 Carbon atoms out. Matter is conserved, never created or destroyed.

The Great Energy Loop: Plant vs. Animal

Two Complementary Reactions

Photosynthesis (Storage)

Organelle: Chloroplast

📥 Takes in: Light + CO₂ + H₂O

📤 Outputs: Glucose + O₂

🔋 Energy Goal: STORES energy in bonds.

🌿 Who does it? Autotrophs (plants, algae).

Cellular Respiration (Release)

Organelle: Mitochondria

📥 Takes in: Glucose + O₂

📤 Outputs: ATP Energy + CO₂ + H₂O

⚡ Energy Goal: RELEASES energy as ATP.

🐾 Who does it? ALL eukaryotes (plants AND animals!).

⚠️ Remember: Plants perform photosynthesis during the day, but they respire 24 hours a day!

Factors That Control the Speed

Limiting Factors

1. Light Intensity

Brighter light energizes chlorophyll faster.

📈 Rate rises steadily, then levels off once all chloroplasts work at maximum capacity.

2. CO₂ Levels

Carbon is the primary chemical ingredient.

🫧 More dissolved CO₂ boosts glucose synthesis until enzymes become saturated.

3. Temperature

Photosynthetic enzymes need optimal warmth.

🌡️ Peak rate at 20°C–30°C (68°F–86°F). Too cold slows down; extreme heat denatures enzymes!

🧪 Next Up: Let's conduct our Elodea plant bubble inquiry in the lab worksheet! End of Presentation

Key Takeaway: The vast majority of a giant tree's physical solid mass comes from the invisible gas ___________________!

5. Comparing the Two Great Cellular Reactions

6. Three Limiting Factors Controlling Photosynthetic Speed

1. Light Intensity

As light intensity increases, the rate of photosynthesis _______________ until it reaches a maximum plateau.

2. Carbon Dioxide Concentration

Adding more dissolved CO₂ provides raw materials, causing the rate to _______________.

3. Temperature

Enzymes speed up as it warms, but if temperature gets too hot, enzymes become _______________ and rate drops to zero.

Unit 2: Photosynthesis • Student Guided Notes Page 2 of 2

0 10 cm 20 cm 30 cm 40 cm 50 cm

↑ Y-Axis: Rate (Bubbles/Min) X-Axis: Lamp Distance from Plant (cm) →

Part 4: Claim • Evidence • Reasoning (CER) Argument

Prompt: How does distance from a light source impact the rate of plant photosynthesis?

CLAIM (Directly answer the question in one complete sentence):

EVIDENCE (Cite at least two specific numerical data points from the lab table):

REASONING (Connect your evidence to chloroplasts, light energy, and photon absorption):

Part 5: Extension: The Green Filter Mystery

If the students placed a green transparent film over the lamp at 10 cm, predict what would happen to the bubble count. Explain your reasoning using chlorophyll light absorption.

Unit 2: Photosynthesis • Student Investigation Worksheet Page 2 of 2

Section 2: Chlorophyll: red & blue, green. Thylakoid: water. Stroma: glucose.

Section 4: Mass tracking: CO₂, H₂O, oxygen. Tree mass takeaway: Carbon Dioxide.

Section 5 (Table): Photosynthesis: Store | Chloroplast | Light | Oxygen | Autotrophs. Respiration: Energy (ATP) | Mitochondria | Oxygen | Animals.

Photosynthesis Lab Worksheet Key

Part 1 (Atom Balancing): Carbon: 6 & 6; Hydrogen: 12 & 12; Oxygen: 18 & 18. Conserved perfectly!

Part 2 (Variables): 1. Distance of lamp (light intensity) | 2. Rate of oxygen bubbles per minute | 3. Oxygen gas (\(\text{O}_2\)) released during photolysis of water.

Part 4 (Exemplar CER Response):

• Claim: As the distance between the plant and light source decreases, the rate of photosynthesis increases significantly.
• Evidence: At 10 cm, the plant released an average of 50 bubbles/min, whereas at 50 cm, bubble production plummeted to only 6 bubbles/min.
• Reasoning: Closer lamp proximity delivers higher photon energy to chlorophyll pigments in thylakoid membranes, speeding the splitting of water molecules and accelerating glucose synthesis.

Part 5 (Green Light Extension): Bubble production would drop drastically near zero because chlorophyll reflects green light rather than absorbing it.

Quick Check Answers

1. B (Glucose and oxygen gas) • 2. C (Carbon dioxide gas from air incorporates into cellulose and lignin).

Scientific Explanation (CER) Evaluation Rubric

Unit 2: Photosynthesis • Teacher Facilitation & Assessment Page 2 of 2

Matter & Energy Conservation Reflections:

1. Why is arrow [A] (Sunlight) called an energy flow rather than matter?

2. Where does the orange sugar [E] end up during winter when leaves drop?

Unit 2: Photosynthesis • Coloring Worksheet Page 2 of 2