The ultimate source of energy (for most ecosystems) is the sun. The ultimate fate of energy in ecosystems is for it to be lost as heat. Energy and nutrients are passed from organism to organism through the food chain as one organism eats another. Decomposers remove the last energy from the remains of organisms.
The Contribution Limit. For 2013 and 2014. the basic limit for regular contributions to a Roth IRA is $5,500 for people under 50 years of age, and $6,500 for those who are 50 or older. (Numbers like this can be found in our Reference Room.) This limit may be reduced for any of the following reasons:
Determine your maximum contribution. Take into consideration the standard limits on contributions as well as how much you can afford. 1  Through 2014, the limit for contributions to a Roth IRA is $5,500 if youâre younger than 50 years old. 2  If you are 50 years old or older, the annual limit is $6,500.