A 1-mol sample of an ideal diatomic gas at pressure of 1 atm and temperature of 490 K undergoes a process in which its pressure increases linearly with temperature. The final temperature and pressure are 720 K and 1.6 atm. Determine (a) the change in internal energy, (b) the work done by the gas, and (c) the heat added to the gas. (Assume 5 active degrees of freedom.)

I just want to know that, is the volume constant? Why?

What does (Assume 5 active degrees of freedom.) mean?