At its simplest, biotechnology is technology based on biology - biotechnology harnesses cellular and biomolecular processes to develop technologies and products that help improve our lives and the health of our planet.
In macroeconomics, the focus is on the demand and supply of all goods and services produced by an economy. Accordingly, the demand for all individual goods and services is also combined and referred to as aggregate demand.
To aggregate is to collect many units into one. If you're writing a novel, you might create a character who is an aggregate of five or six real people. Aggregate comes from the Latin verb aggregare, which means to add to. As a verb it means to collect into a mass or whole. You can also use it as an adjective, as in your aggregate sales for February, March and April. It can also be a noun.