  We investigate conformations and dynamics of a polymer considering its
monomers to be active Brownian particles. This active polymer shows very
intriguing physical behavior which is absent in an active Rouse chain. The
chain initially shrinks with active force, which starts swelling on further
increase in force. The shrinkage followed by swelling is attributed purely to
excluded-volume interactions among the monomers. In the swelling regime, chain
shows a cross-over from the self-avoiding behavior to Rouse-behavior with
scaling exponent $\nu_a \simeq 1/2$ for end-to-end distance. The
non-monotonicity in the structure is analysed through various physical
quantities specifically, radial distribution function of monomers, scattering
time, as well as various energy calculations. The chain relaxes faster than the
Rouse chain in the intermediate force regime, with a cross-over in variation of
relaxation time at large active force as given by a power-law $\tau_r \sim
Pe^{-4/3}$ (P e is P\'eclet number).
