Well, there are two kinds of organisms: osmoregulators, that can regulate the level of salt and the salinity does not affect them (an example is salmon: for salmon this sentence is true. Generally, for most fish this sentence is true)
However, for some species, such shark - osmoconformers - this is false: they are affected by the salinity. in general I would conclude that This is false: the marine salinity DOES affect the fish (and other organisms) living there.
I can’t really see the questions
A chromosome is a strand of DNA that is encoded with genes. In most cells, humans have 22 pairs of these chromosomes plus the two sex chromosomes (XX in females and XY in males) for a total of 46.