So, I'm guessing everyone in this thread has a different conception of what "consciousness" actually is and what we're talking about here, which makes it difficult to discuss casually like this. You seem to have a very exclusive definition of consciousness, which only serves to avoid the argument, really. "It’s possible that same organisms exhibit some parts of consciousness as we have noticed till now, but if those organisms do not exhibit all parts of consciousness then they’re not conscious"...you're splitting hairs. If plants could be proven to be aware, have subjective experience, a sense of self, it would be reasonable to change our definition of consciousness to be more inclusive - simply because such a concept of consciousness would be a lot more useful then.

Emergentism is a popular hypothesis, not a fact. Christof Koch lost the bet, remember? The idea that "all organisms which are conscious have to exhibit the same properties" and "you cannot pick and choose" does not logically follow from anything you've said. These are criteria that you set up yourself. Take the idea of qualia as an example, how could we ever observe that an animal or a plant does or does not experience qualia? Nobody solved the problem of other minds.

Consciousness is nothing like a heart; the function of the heart can be observed and measured. How do you know that you possess awareness? You can only experience it. (Actually, that we are aware is the only thing we can know with complete certainty.)