Throughout human history, major migrations have been spurred by sharp decreases in the availability of food caused by hazards or changes in climate. For example

Each member of a class sampled a piece of ptc testing paper. thirty people sampled the chemical. twenty persons were tasters. how many had heterozygous genes? 10 20 0-20 indeterminate

What are some of the immune functions of the lymphatic system? a. cleaning red blood cells from the blood and creating lymph fluids b. transporting lymph to the tissues and creating lymph fluids c. removing infectious agents and making white blood cells d. making red blood cells and removing infectious agents

Which is abiotic? a. tree sap b. insect c. sunlight d. wood table