Algebraic cycles on a real algebraic GM-manifold and their applications

For an algebraic cycle $Y\in A_k(X)$ on a real algebraic $\operatorname{GM}$-manifold $X$, the relationship between the homology classes $[Y(\mathbf C)]\in H_{2k}(X(\mathbf C),\mathbf Z)$ and $[Y(\mathbf R)]\in H_k(X(\mathbf R),\mathbf F_2)$ is studied. It is shown that similar relations hold for smooth cycles on a $\operatorname{GM}$-surface. The results are applied to prove congruences for the Euler characteristic of the set $X(\mathbf R)$.