Plants

🌿 PLANT BIOLOGY QUIZ — ESSENTIAL NOTES

🔥 1. Photosynthesis (VERY IMPORTANT)

Equation (memorize):
CO₂ + H₂O → glucose + O₂ (with light)

Key facts:

  • Happens in chloroplasts

  • Uses light energy → chemical energy (glucose)

  • CO₂ enters, O₂ leaves

🔥 2. Leaf Structure (DIAGRAM ALERT)

Must know:

  • Palisade mesophyll → photosynthesis (lots of chloroplasts)

  • Spongy mesophyll → air spaces for gas exchange

  • Stomata → pores for gas exchange

  • Guard cells → open/close stomata

📌 DIAGRAM YOU SHOULD KNOW:

👉 Cross-section of a leaf showing:

  • upper epidermis

  • palisade mesophyll

  • spongy mesophyll (air spaces)

  • stomata + guard cells (bottom)

🔥 3. Stomata + Transpiration

  • Stomata let CO₂ in, but water leaves (trade-off)

  • Transpiration = water loss from leaves

  • Creates “pull” that moves water up plant

Guard cells:

  • Turgid (day) → open stomata

  • Flaccid (night) → closed stomata

🔥 4. Xylem vs Phloem (VERY TESTED)

Xylem

Phloem

Water + minerals

Sugars (glucose)

ONE direction (up)

TWO direction

Dead cells

Living cells

Thick walls (lignin)

Sieve tubes + companion cells

📌 DIAGRAM YOU SHOULD KNOW:

👉 Stem cross-section showing:

  • xylem (inside)

  • phloem (outside)

  • vascular bundle arrangement

🔥 5. Monocots vs Dicots (MEMORIZE TABLE)

Feature

Monocot

Dicot

Cotyledons

1

2

Veins

parallel

net-like

Roots

fibrous

taproot

Stem bundles

scattered

ring

Flowers

3s

4s or 5s

📌 DIAGRAM YOU SHOULD KNOW:

  • monocot leaf vein pattern vs dicot leaf vein pattern

  • fibrous root vs taproot

🔥 6. Transpiration (HIGH FREQUENCY QUESTION)

  • Water evaporates from leaves

  • Creates negative pressure (pull)

  • Pulls water up xylem

Factors that increase transpiration:

  • light ↑

  • wind ↑

  • temperature ↑

  • humidity ↓

🔥 7. Plant Hormones (SHORT ANSWER TOPIC)

  • Auxin → growth toward light (phototropism)

  • Gibberellins → stem growth + seed germination

  • Cytokinins → cell division / branching

  • ABA → stress hormone (closes stomata in drought)

📌 DIAGRAM YOU SHOULD KNOW:

👉 Phototropism diagram:

  • plant bending toward light

  • auxin moving to shaded side

🔥 8. Pollination & Fertilization

Pollination = pollen → stigma

Types:

  • wind

  • insects/animals

  • self

Fertilization:

  • pollen joins ovule → zygote

  • becomes seed

  • endosperm feeds embryo

📌 DIAGRAM YOU SHOULD KNOW:

👉 Flower structure:

  • stigma

  • style

  • ovary

  • ovule

  • anther

🔥 9. Flowering Timing (simple version)

  • Controlled by light/dark length

  • Long-day plants → flower in short nights

  • Short-day plants → flower in long nights

  • Controlled by phytochromes

🧠 WHAT TO PRIORITIZE TONIGHT (MOST LIKELY QUIZ CONTENT)

If time is tight, focus on:

  1. Photosynthesis equation + chloroplast

  2. Leaf diagram

  3. Xylem vs phloem

  4. Monocot vs dicot table

  5. Stomata + transpiration

  6. Flower diagram

🧾 QUICK MEMORY TRICK

  • Xylem = water UP

  • Phloem = food BOTH

  • Stomata = gas + water loss gate

  • Auxin = bending toward light

  • Transpiration = water pull