What effect do calcium ions have on the water in ecosystems? a. they reduce its ph. b. they decrease its salinity. c. they add to its hardness. d. they increase its acidity.

Which layer will become saturated first when rain falls?

During dna replication,each strand of dna is used as a template to produce a complementary strand of dna. this process is shown below. which base will attach to location

Dna in the nucleus carries the genetic code for making proteins in ribosomes. the diagram shows a model of dna. which part of the dna molecule codes for the amino acid sequence in the protein? a) sugar b) phosphate c) deoxyribosed) nitrogen bases