Which of the following is the cause for different seasons on earth?

A. The direction earth spins around it's axis

B. Changing levels of gas compositions throughput the year

C. The distance from earth to the sun

D. The way earth has a tilted axis

Does species are largest unit of life?

If a mineral leaves a red trail when scraped against an unglazed porcelain plate which properly of a mineral is being measured

Why are valves present in veins but not in arteries?

A type of multicellular animal that consists of cells with little specialization is a tapeworm sponge bee jellyfish

To be activated CPR must first bind? a. the co-repressor molecule b. the repressor molecule c. the repressor protein d. cAMP e. the activator protein

if research is restricted. then the new discoveries made are limited. which action is most likely to increase the number of discoveries scientist can make?

Which statement about nuclear fission is false? a: nuclear fission takes place in the core of the stars b: the fuel for nuclear fission is often uranium c: nuclear fission releases large amount of energy d: nuclear fission is used to generate

Some monkey flowers (Mimulus guttatus) living near the sites of copper mines can grow in soil containing high concentrations of copper, which is toxic to most plants. Copper tolerance is a heritable trait. Select the three statements that are true.

The lowest level of environmental complexity that includes both living and nonliving factors is the A: Biome B: Community C: Ecosystem D: Biosphere

Which part of the endocrine system is located in the middle of the brain