Final answer:
Dormancy due to rudimentary embryo is a survival strategy where a seed's development is suspended, resulting in a dormant state that allows it to endure adverse conditions until favorable conditions for germination are met. The seed's metabolic rate decreases and it can survive for extended periods. ABA, a key hormone, helps induce and maintain this dormancy.
Step-by-step explanation:
Dormancy due to a rudimentary embryo refers to a state in which a seed contains an embryo that has ceased development at a very early stage, resulting in the seed becoming inactive or 'dormant'. This inactive state is characterized by a low metabolic rate and enhanced tolerance to environmental extremes such as temperature, which allows the seed to withstand various conditions during dispersal. A well-known example lies in the development of the embryonic seedling of Capsella bursa, where after a period of initial growth, the embryo and cotyledons become constrained by the seed's boundaries and eventually the development is suspended.
Dormancy is a survival strategy for seeds, allowing them to pass through time until conditions are favorable for germination. Environmental signals such as moisture, warmth, or specific photoperiod can trigger the end of dormancy. Notably, ABA (abscisic acid) plays a crucial role in inducing seed dormancy by repressing germination and is gradually broken down to release the seed from its dormant state when conditions improve, particularly in temperate climates that experience different seasons.