It’s a wonder you can’t detect a pulse from a seed, considering all the life within.

Even before they germinate, you can predict how their life cycle will evolve. Each seed carries a genetic mix that determines hardiness and disease tolerance, plant size, texture and color and distinctive blooms or fruit.

Then there are the differences visible only to the practiced eye between conventional seeds and their organic equivalents. The variations can make all the difference in your garden.

``They come from altogether different circumstances so they have altogether different traits,’’ said Frank Morton, a seedsman and plant breeder from Philomath, Ore.

Organic seeds are often large _ containing their own food reserves. Their roots dig deeper to mine the soil and spread leaves quickly to stay ahead of weeds. In other words, they can flourish in poor soil and compete with other plants.

Organic growers are learning to expect more vigor from their seeds, Morton said. While conventional seeds and hybrids often have one gene that stands up to pathogens, organic seeds have the kind of disease resistance found in nature.

``That means a variety of things working together to give a plant a strong constitution and a better ability to combat ailments,’’ he said.

Then there are the environmental benefits.

``Commercial seed growing is one of the most intensive users of farm chemicals going,’’ said Jim Gerritsen, who with his wife, Megan, operates WoodPrairie Farm in Bridgewater, Maine.

In conventional seed production, soil must be free of ``plant pests,’’ so the ground is often drenched in chemicals, he said. Organic seeds are free of that kind of production _ and good ones are also bred to resist pest pressures.

It remains debatable, though, whether organic seeds produce a more flavorful harvest than conventional strains.

Morton says it’s no contest when he compares conventional tomatoes to organic _ although that may be because he’s getting them locally, so they aren’t traveling as far after being picked. And genes eventually tell.

``You can give them all the composts and fertilizers and clean things you want but if a particular carrot isn’t genetically predisposed to crispness, it won’t make any difference,’’ Morton said.

In the grand scheme of backyard gardening, working with organic seeds is more a matter of lifestyle than it is utility, said Ellen Ogden, of Manchester Village, Vt., co-founder of the ``The Cook’s Garden,’’ a seed catalog for gardeners who love to cook.

``We need to be more careful with what we’re putting into the ground,’’ said Ogden, who designs kitchen gardens. ``Herbicides and everything else. Whoever uses organic seeds is thinking a little more about what they’re doing