Final Revision Flashcards
What are the fundamental units of plant life?
Plant cells
Distinct from animal cells due to their rigid cell walls made of cellulose.
What is the function of chloroplasts in plant cells?
Site of photosynthesis
Enables plants to convert sunlight into energy.
What does the nucleus of a plant cell control?
Cell activities and contains DNA
What is the role of mitochondria in plant cells?
Generate ATP for energy
What is the function of the vacuole in plant cells?
Stores nutrients and maintains turgor pressure
What do the endoplasmic reticulum and Golgi apparatus do?
Involved in protein and lipid transport
What regulates what enters and exits the plant cell?
Plasma membrane
What are plasmodesmata?
Allow communication between plant cells
What are the main parts of a flower?
- Sepal
- Petal
- Stamen (anther + filament)
- Carpel (stigma, style, ovary)
What is the first step in the fertilisation process of plants?
Pollination: Pollen lands on the stigma
What occurs during pollen tube formation?
Pollen tube grows through the style to the ovary
What is double fertilisation in plants?
- One sperm cell fuses with the egg cell to form a diploid (2n) zygote
- The other sperm cell fuses with two polar nuclei to form a triploid (3n) endosperm
What is a superior ovary?
Ovary is above the attachment of other floral parts
What is a dioecious flower?
Male & female flowers on separate plants (e.g., holly)
What is vernalisation?
Cold exposure induces flowering
What are the parts of a seed?
- Embryo
- Cotyledon(s)
- Radicle
- Hypocotyl
- Epicotyl
- Seed coat
What distinguishes endospermic seeds from non-endospermic seeds?
- Endospermic: Seeds contain endosperm as a food reserve (e.g., wheat)
- Non-Endospermic: Food reserves stored in cotyledons (e.g., beans)
What is the first step of germination?
Imbibition: Seed absorbs water and swells
What activates enzymes and hormones during germination?
Water
What stimulates the aleurone layer in endospermic seeds?
Gibberellic Acid (GA3)
What breaks down starch into sugars in endospermic seeds?
Alpha-amylase
What is innate dormancy?
Genetic dormancy, preventing germination even in favourable conditions
What are two types of dormancy?
- Innate Dormancy
- Induced Dormancy
What natural factors can break dormancy?
- Temperature fluctuations
- Light exposure
- Microbial action
What is the difference between epigeal and hypogeal germination?
- Epigeal: Cotyledons emerge above soil (e.g., beans)
- Hypogeal: Cotyledons remain underground (e.g., peas)
What is the vascular cambium?
A lateral meristem that develops between primary xylem and phloem
What does the vascular cambium produce?
- Secondary xylem (wood) inward
- Secondary phloem outward
What are the main functions of xylem and phloem?
- Xylem: Transports water & minerals from roots to shoots
- Phloem: Transports sugars and organic compounds
What hormone promotes cell elongation?
Auxins
What do cytokinins stimulate?
Cell division and lateral bud growth
What is the effect of gibberellins (GAs)?
Promote stem elongation, seed germination, flowering
What does abscisic acid (ABA) regulate?
Seed dormancy and stomatal closure
What influences fruit ripening?
Ethylene
What is apical dominance?
Auxins inhibit lateral bud growth
What effect does pruning have on plants?
Enhances branching by removing the dominant apical bud
What abiotic factors affect plant growth?
- Light
- Temperature
- Humidity
What are macronutrients essential for plant health?
- Nitrogen
- Phosphorus
- Potassium
What happens in acidic soils (pH < 6)?
Reduces phosphorus availability
Use Diagrams
What is an effective learning method involving teaching others?
Active Recall
Fill in the blank: _______ can help you focus on weak areas.
Flashcards
