Which of the following is not a health effect caused by exposure to volcanic gases? backaches
suffocation
dizziness
headaches

Which of the following statements is true? a. the main cause for speciation is an increase in gene flow. b. organisms that reproduce asexually are not considered part of a species. c. on a tree of life diagram, speciation is shown by the merging of two different lineages. d.the size of the geographic area inhabited by a population can cause speciation.

Wich level of organization includes all the other levels or organizations

Ascientific idea becomes valid when it is what?