Describe the structure of the molecule Y. (3) Describe the arrangement of molecules in part Y (4)
Describe three functions of the cell membrane. (3)

The friction red blood cells encounter when moving past each other. cardiac output: the amount of friction blood encounters during flow through blood vessels. blood pressure: the force of the blood against the vessel wall. blood viscosity: the volume of blood pumped out by one ventricle each minute.

Consider the skeleton. which skeletal system is represented by the shaded portion of the skeleton? spongy skeleton compact skeleton axial skeleton appendicular skeleton

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?