What could form over land as a result of a continental polar air mass from Canada meeting a maritime tropical air mass from the Gulf of Mexico?

Graphs you see question 5 options: the change in data over time the relationship between different dependent variables the relationship between the independent variable and the dependent variable/s the relationship between different independent variables

Natural selection changes allele frequencies because some survive and reproduce more successfully than others.

What is the one part of the nucleotide  that differs among the other different nucle  tides?