how have fresh water and salt water fish adapted to deal with osmosis in their respective environments?

In general, characteristics that an organism survive and reproduce become more common over time. what mechanism of evolution causes this?

Which of the following types of pollution is most responsible for large numbers of deaths worldwide because of unsafe drinking water? (a) nutrient pollution (b) thermal pollution (c) pathogen pollution (d) sediment pollution

All annelids and arthropods have a blank body plan . unlike annelids, arthropods also have blank . the circulatory system of annelids is blank , while circulatory system of arthropods is blank .