Explain two difficulties an ecologist might have in counting a population of migratory birds

Heterotrophs are animals that?

Name the two molecules which alternative to make the side portions or backbone of a DNA model.

Explain why there are a wide variety of phenotypes for skin color in humans.

How you know that paraquat did not cause the coral bleaching

There are the same number of these two particles in an atom

How do substances move in passive transport?

Atmosphere: is mostly made of nitrogen is weightless protects earth from harmful radiation contains water vapor is affected by events in the hydrosphere

According to this species-area curve for reptiles and amphibians on a west indian archipelago, a 50% decrease in area will change the number of species living in the remaining area by

How do organelles interact within a cell

How do we detect the energy of a wavelength?