Essential Mnemonics

1. Embryo sac count — "1-2-3-2"

• 1 egg cell
• 2 synergids
• 3 antipodal cells
• 2 polar nuclei = 7 cells, 8 nuclei

2. Egg apparatus location — "Eggs Sit at the Micropyle"

• E = Egg cell (center)
• S = Synergids (flanking)
• M = Micropylar end (location)

3. Double fertilization — "Simple + Triple = Double"

• Simple (syngamy): 1 sperm + 1 egg = 2n (1+1=2)
• Triple: 1 sperm + 2 polar nuclei = 3n (1+2=3)
• Double = Two fusions happening simultaneously

4. Post-fertilization transformations — "OOIPS"

• Ovule → Seed
• Ovary → Fruit
• Integuments → Seed coat
• PEN → Endosperm
• (Zygote → Embryo — the "S"tarting point of the new plant)

5. Outbreeding devices — "S-D-D"

• Self-incompatibility
• Dicliny (unisexual flowers)
• Dichogamy (different maturation times)

6. Geitonogamy — "Geno = Gene (same genotype), Eco = Ecologically cross"

• "Geitonogamy looks cross but IS self" (Genetic lie)

7. Pollination agents — "WIBW" (Wind-Insects-Birds-Water-Bats)

• Wind → feathery stigma, light pollen
• Insects → sticky pollen, bright colours, nectar
• Birds → red/orange, copious nectar, no scent
• Water → mucilaginous pollen, reduced flowers
• Bats → nocturnal, strong fruity scent, dull colour

8. Sporopollenin properties — "4-No" (4 things that CAN'T break it)

• No heat (resistant to high temperature)
• No acid (resistant to strong acids)
• No alkali (resistant to strong alkalis)
• No enzyme (resistant to enzymatic degradation)