Biology: Plant Growth and Development

Plant Movements

• Hydrotropism: plant response to water
• Gravitropism/Geotropism: plant response to gravity
• Phototropism: plant response to light
• Thigmotropism: plant response to touch
• Plant Transport: growth movement whose direction is determined by the direction from which the stimulus strikes the plant

Reproduction in Plants

• Asexual reproduction: new plant arises from vegetative parts, no seed formation
• Sexual reproduction: new plant arises from reproductive part, fruits and seeds are formed

Organic Compounds

• Made up of carbon and hydrogen bonds
• Macromolecules are large molecules made up of building blocks called monomers acquired from food
• Examples of carbohydrates: monosaccharides (glucose, fructose, galactose), disaccharides (sucrose, maltose, lactose), polysaccharides (starch, glycogen)
• Proteins: molecules with different functions in living things, examples: enzymes, antibodies, muscle fiber
• Lipids: molecules such as fats, oils, and waxes

Plant Form and Physiology

• Shoot system: all parts above ground
• Root system: all parts underground
• Tissues:
  • Meristematic tissues/meristems: constantly dividing cells that can specialize
  • Permanent tissues: no longer constantly dividing, differentiated into three categories
• Primary growth: apical meristems, makes the plant taller/longer
• Secondary growth: lateral meristems, makes the stem thicker/wider
• Phyllotaxy: leaf arrangement

Plant Nutrition and Transport

• Water transport: cohesion-tension theory
• Nutrient transport: source to sink, driven by water moving from xylem to phloem near sources
• Macronutrients: needed in large amounts, examples: C, H, O, N, P, K, Ca, Mg, S
• Micronutrients: needed in trace amounts, examples: Fe, Mn, B, Mo, Cu, Zn, Cl, Ni, Co, Na, Si

Cellular Structure and Function

• Desmosome: adjacent plasma membranes, plaque, transmembrane glycoprotein (cadherin), intermediate filament (keratin), intercellular space

Metabolism

• Glycolysis: energy-requiring steps (1-5, 2 ATP consumed), energy-releasing steps (6-10, 4 ATP produced)
• Oxidative Phosphorylation/Electron Transport Chain: only part that uses oxygen, produces the most ATP
• Metabolism without oxygen:
  • Anaerobic respiration: uses other molecules other than oxygen for the electron transport chain
  • Lactic acid fermentation: pyruvate is reduced to lactate, allows for NAD+ regeneration
  • Alcohol fermentation: also allows for NAD+ regeneration

Life Functions

• Metabolism: undertaking of essential chemical reactions that involve combining simple molecules to form a complex substance (anabolism) and breaking down complex substances into simpler molecules (catabolism)
• Reproduction: produce offspring, either sexually or asexually
• Responsiveness/Sensitivity: responding to internal or external stimuli
• Movement: motion not only of the physical body but also individual organs and individual cells
• Development: changes the body goes through in life such as growth, repair, and differentiation