Questions

Phoebus Levene was an organic chemist in the early 1900's. He is perhaps best known for his incorrect tetranucleotide hypothesis of DNA. He is who studied the structure and function of nucleic acids.

The discovery of Identification of Ribose and Deoxyribose is attributed to Phoebus Levene.

The two broad categories of software in a computer are

1. System software
2. Application software

System software controls how the system works and enables user to access all of the system hardware and application software

The OS, utility programs and drivers come under system software.

Application software are software used by the user to perform specific task. They are installed according to the user's requirements.

The word processor, web browser, players, spreadsheets etc... come under this application software.

The energy sources that are constantly being replenished, such as sunlight, wind, and water. This means that we can use them as much as we want, and we do not have to worry about them running out. Additionally, renewable energy sources are usually much more environmentally friendly than fossil fuels. Overall, they release very few chemicals, like carbon dioxide, that can harm the environment.


Most of this energy comes from fossil fuels, such as coal, oil, and natural gas. These are nonrenewable energy sources, which means that if we use them all up, we can never get more during our lifetime. Fossil fuels also contribute greatly to global climate change by releasing carbon dioxide into the air when they are burned.

Hindol Sengupta