Biology 11th Edition by Gerald Audesirk,Teresa Audesirk,Bruce Byers

تمرين 9

Seedless vascular plants must reproduce when conditions are wet because their sperm must ______________. Two adaptations that allow seed plants to reproduce more efficiently on dry land are ______________ and ______________. The seed plants fall into two major categories: the nonflowering ______________ and the flowering ______________. Flowers were favored by natural selection because they ______________. Fruits were favored by natural selection because they ______________.