Error 1: Endosperm Ploidy

The single most common NEET error is choosing "diploid (2n)" for endosperm ploidy. Endosperm is TRIPLOID (3n). It forms from triple fusion: 1 sperm (n) + 2 polar nuclei (n+n) = 3n. Never confuse with the zygote (2n, from syngamy).

Error 2: Embryo Sac Count

Students often write "8 cells" for the embryo sac. The correct answer is 7 CELLS and 8 NUCLEI. The central cell has two polar nuclei, creating the discrepancy between cell and nucleus count.

Error 3: Geitonogamy and Genetic Variation

A very common trap: geitonogamy is described as cross-pollination, so students assume it promotes genetic variation. It does NOT. Both flowers belong to the same plant (same genotype), so geitonogamy is genetically self-pollination with zero genetic variation introduced.

Error 4: Double Fertilization Requires Two Pollen Grains

Only one pollen grain is required. Its generative cell divides to produce two sperm cells — one for syngamy and one for triple fusion. Two fertilization events from one pollen grain.

Error 5: Sporopollenin Location

Sporopollenin is in the EXINE (outer pollen wall), not the intine. The intine is soft $\frac{cellulose}{pectin}$ and forms the pollen tube.

Error 6: Post-Fertilization Confusion

Ovule → SEED (not fruit); Ovary → FRUIT (not seed). The integuments → seed coat. The PEN → endosperm (3n). The ovary wall → pericarp (fruit wall). These four transformations must be memorized precisely.

Error 7: Cleistogamy as Outbreeding

Cleistogamy is INbreeding (obligate autogamy). It is NOT an outbreeding device. The three outbreeding devices are self-incompatibility, dicliny, and dichogamy.