The wind makes pollination possible for gymnosperms. In gymnosperms ovaries are absent and the gametophytes of these plants are present on cones rather than flowers. Unlike angiosperms that get pollinated with animal interference, wind plays a crucial role in gymnosperm pollination.
Even the cell membrane is like the cell wall its flexible and lets certain things in and certain things out.
Answer:
Wetland reduction has caused a decrease in the absorption zones for excess water. If the excess water cannot be absorbed by the soil, it increases the incidence and magnitude of flooding.
Material through which water flows is permeable. This material can be either natural or artificial. Naturally permeable material can be clean sand and gravel for example, or a sandstone and in the latter case the sandstone can have both porosity which is not synonymous with permeability as the pores must be connected to be permeable. An impermeable membrane could be used to line ditches for example to prevent leakage near mines.
Genetic variation occurs.
Mutations are not copied over and over again.
