The hormone , which is secreted by the pineal gland, influences the sleep–wakefulness cycles.

Which statements describe resources? one of the factors people use when deciding where they will live is the availability of resources. renewable resources have little value for people. resources are unevenly distributed throughout the world. energy is the world resource which has the highest use. the use of nonrenewable resources has decreased in recent history. the use of resources is evenly distributed throughout the world. the world's oil supply will last for the next forty years if its use continues as expected.

The variation among individuals, on which natural selection acts

Which is essential for finding the biomass of spinach