Which of the following is a source of genetic varitaion in sexualy-reproducing organisms

Which of the following is required of a new drug?me

Which of the following is an abiotic factor in an ecosystem? a. bacteriab. airc. niched. grass(abiotic=non-living) me !

How do you think earths interior affects what is happening on the surface? 2. how do fossils support the continental drift hypothesis? 3. how does sea- floor spreading support the hypothesis of continental drift? 4.what do scientists observe when they studied the magnetic fields of rocks on the sides of mid-ocean ridges? 5. what is a tectonic plate ? 6. explain mantle convection 7.how can movements of the continents affect earths climate? 8. what occurs during drifting?