AP BIOLOGY

Detailed explanation-1: -During germination of a seed, the reserve food material stored in the seed is used up in the formation of seedling hence the dry weight decreases.

Detailed explanation-2: -As seeds imbibe water, they expand and enzymes and food supplies become hydrated. Hydrated enzymes become active and the seed increase its metabolic activities to produce energy for the growth process. In addition, the water causes turgor pressure to increase in the cells and they are able to enlarge.

Detailed explanation-3: -The dry mass increases steadily similar to an increase in the number of days the seeds are left to germinate since there is a decrease in the transfer of materials from endosperm or cotyledon. There is a steady increase of dry mass, the more the days that these seeds are left to germinate.

Detailed explanation-4: -Seed size (mass) can affect germination time, germination percentage, dispersal, seed water relation, as well as seedling establishment, growth, survival, and thus it has important ecological consequences1, 2, 3, 4, 5.

Detailed explanation-5: -During the beginning stage of germination, the seeds take up water rapidly and this results in swelling and softening of the seed coat at an optimum temperature. This stage is referred to as Imbibition. It starts the growth process by activation of enzymes.