Let $N,G,G^\prime$ be three affine algebraic group varieties (i.e geometrically reduced in the sense of J. Milnes) defined over a separably closed field $K$. Suppose that we have the following exact sequence: $$e\rightarrow N\rightarrow G\rightarrow G^\prime\rightarrow e$$

which means $N$ is a subgroup variety of $G$, and the $G\rightarrow G^\prime$ is faithfully flat. My question is considering the $K$-points, do we still have the following exact sequence: $$e\rightarrow N(K)\rightarrow G(K)\rightarrow G^\prime(K)\rightarrow e?$$