The polarity of a plant is established when ________.
A) cotyledons form at the shoot end of the embryo
B) the shoot-root axis is established in the embryo
C) the primary root breaks through the seed coat
D) the shoot first breaks through the soil into the light as the seed germinates

Question

Quizplus · Accepted Answer

The establishment of the shoot-root axis in the embryo determines the polarity of the plant, as it determines which end will become the shoot and which end will become the root. Cotyledons forming at the shoot end of the embryo (A) and the primary root breaking through the seed coat (C) are important developmental events but do not establish the plant's polarity. The shoot breaking through the soil (D) occurs after the establishment of polarity.

The Polarity of a Plant Is Established When ________