Help me please with this biology

Astudent observes a star from two positions of earth in its orbit, in summer and winter, and measures the change in the position of the star. which of these can be best calculated by this method?

Which group is noted for the independence of gametophyte and sporophyte generations from each other? a) ferns b) mosses, hornworts, and liverworts c) charophytes d) angiosperms e) gymnosperms

The smallest parts of these that retain their original properties are called