I don't think transmutation is possible on a wide scale due to financial costs, but it could be physically possible. It will only be affordable to rich people, though.
I think we'll be immune to bacteria and viruses due to nanobot technology. Nanobots could be programmed to recognize and attack foreign objects circulating in the blood. What stops the spread of this panacea for all harmful diseases is, again, cost. If you're too poor to afford an injection of nannites, tough luck. The poor in the third world would be vulnerable of missing out.
We won't make it past Mars in 100 years or not much further than mars or even other star systems; I don't think technology is moving fast enough for such a timeframe. We could have a firm grasp on the moon, though, due to advances in propulsion technology.
A second age of imperialism dawns where world powers wage war over colonial rights on the Moon, Mars and resource rights found on that, Mars, and the mineral and ore rich asteroid belt. Nations will attack space colonies of other rivals and attack orbital space colonies. People will be killed in tremendous numbers the technology of war was simply so much more advanced, and so much more deadly than in previous centuries.
True, humans will live longer due to advances in medicine, but again, the poor would be at risk of being left behind, and it's likely some were left behind.
Not sure about animal breeding though. It probably will be technologically possible though, including human cloning. I find the idea of chimeras, animals made from combining several other animals, abhorrent though.
We probably will have the ability to feed everyone, but as I keep bringing up, the poorest would be most vulnerable from being left out for lack of affordability, human greed being what it is.
That's how I generally view the future reading your responses. There's always somebody there to ruin and damage and render things less than what they could have been in the name of greed and the lust for power.
Space colonies:
Warships in space:
New propulsion systems: