The more “professional” indoor grow rooms use a C02 generator.
If you’re going with a 50-year-out-of-date definition of “animal”, yeah. Decay is a complex process, but by and large bacteria (Monera) are the most important players.
True for mollusc shells, and IIRC only molluscs (and some corals). Vertebrate bones are hydroxyapatite, calcium phosphate with a bound water molecule incorporated.
I recommend you eat sugars and starches (carbohydrates) instead of inhaling them. 
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I may have missed it, but one of the largest day-in/day-out producers of atmospheric CO2 is vulcanism. And don’t equate this with “volcanic eruption” – the venting of CO2 happens at places like Yellowstone, dormant or post-shield (‘extinct’) volcanoes, and faults above subduction zones.
I recall reading about the BioDome experiment; where the econuts ignored the experts and loaded the place with excessive composting soil. The problem was that this produced elevated levels of CO2; the CO2 also cleverly invaded the concrete wall foundations, causing a chemical reaction that weakened them considerably. Plus, oxygen levels dropped to dangerously low levels and they had to violate the conditons of the isolation experiment by adding oxygen. Plus, they crashed the ecosystem, the occupants almost starved and were reduced to picking insect pests off crops by hand, to ensure a food supply.
If you are worried about heat and don’t want to vent, why not get an air exchanger and recirculate the internal air? Get CO2 by using mulch that can decay.
One problem with grow operations is that the authorities can detect the excess heat with an infrared detector. It occurs to me that one way of dealing with this would be to use a heat pump to pump the excess heat underground. Essentially, you are running an air-conditioner with the excess heat pumped underground instead of outside. As for CO2, well there is nearly a 1% content in the air around you and plants thrive on that, so just make sure it is well ventilated.
I know you were joking, but you know that respiration != breathing, right?
http://dictionary.reference.com/browse/respiration
''World English Dictionary
respiration (ˌrɛspəˈreɪʃən) [Click for IPA pronunciation guide]
— n
- the process in living organisms of taking in oxygen from the surroundings and giving out carbon dioxide ( external respiration ). In terrestrial animals this is effected by breathing air
- the chemical breakdown of complex organic substances, such as carbohydrates and fats, that takes place in the cells and tissues of animals and plants, during which energy is released and carbon dioxide produced ( internal respiration ) ‘’
Your critical remarks would be easier to tolerate if you knew what you were talking about.
Grow your dope in a room that has no outside wall, or make an inner wall and ventilate that space through the rest of the house. Or grow your dope at the same temperature you keep the rest of the house (72F?). Finally, thermal differences can’t constitute probable cause, because there are many legitimate reasons someone might keep one room warmer than the rest. Maybe granny can’t stand the cold, so needs her room warmer than everyone else. They would have to have some reason to suspect you are growing it in the first place, before thermal imaging could tell the judge “they’re growing it in that house.”
The usual giveaway for a grow op is high power consumpton, to produce enough simulated daylight. In the Holmes on Homes episode where he repaired a grow-op house, they found the occupants had cut a 10-inch round hole in the foundation wall, then fished around in that hole to conect to the buried power feed and bypass the meter.
There was a case I read about in western Canada where two idiots were arrested for a home invasion. They had been walking down the street and smelled the grow-op and busted in - the wrong house. The police used their information to find the right house…
Regardless, any organism (generally) that is not green with chlorophyl uses oxygen and food and creates waste and carbon dioxide. The smaller and single-cell organisms do it with osmosis(?) and the more complex organisms have something like lungs.
As someone who has defended dozens and dozens of grow cases, I can tell you “the usual giveaway” is someone talks. Other than that, smell, power use, and break-ins.
Why? 
Totally covering the entire ceiling with standard 4’ dual-bulb fluorescent fixtures, which would wind up ungodly bright (i.e. plenty for plants, I’ve grown things (not dope) with much less), I still only come up with ~10W/square foot. 100 Amp service would take care of 1000 sq ft, and still leave you with enough power to actually live there, although using 1000 sq ft for your grow-space won’t leave you with much living space in an average sized apartment.
Admittedly, that would cost you about $1.50/hr on your power bill, for every hour those lights were on, but where do the cops get probable cause to look at your electric bill, anyway? They have to have probable cause to get a subpoena before the power company is allowed to give them info on your power consumption. I’m just not seeing it, here. Where do you get that assertion?
I agree with your conclusion, but would point out that optimal lighting conditions are more like 50w/sq ft, of HID lighting, which produces almost twice as many lumens per watt as most cfls. This seems pretty f*&%ing bright, and certainly needs good ventilation to get rid of the heat produced.
In answer to the OP, the best way to re-introduce co2 is to have a passive fresh air intake. That is, a light proof hole, close to the floor, where cool, fresh air can enter as the exhaust fan removes it. This helps to maintain a slight negative pressure in the room, and stops your house smelling of tomatoes.
Heh. But the plants can’t add much more mass than the mass of the sugar you started out with (they’ll be turning the CO[sub]2[/sub] into polysaccharides with, more or less, the same general formula C[sub]n[/sub]H[sub]2n[/sub]O[sub]n[/sub] as sugar).
So, to get enough carbon dioxide for your plants, you need to ferment a whole lot of sugar rich fluids. Then you could use the excess heat to distill the fermentation product out of your sugar rich fluid, and cool the condenser with your air conditioner.
Now all you need to do is decide what to do with all that plant material, and all the condensed fermentation by products.
Maybe outside would be better. It’s the traditional method for pot growing, and moonshining.
Tris
I never said it was an effective way to do it, I just say you could do it. Besides you’d have to refresh the bottle weekly and over the course of a few months you could accumulate a fair bit of extra greenery. Whether it’s all alive at the same time is another question of course. 