Gradually increasing duration and intensity of activity is formally referred to as what

The forms a good substance into small balls and then pushes them into the

How does the endocrine system affect the body's functions? o o o o it secretes enzymes directly into the bloodstream. it secretes hormones directly into the bloodstream. it secretes enzymes through ducts to the surface of organs. it secretes hormones through ducts to the surface of organs.

In 2009, a flu pandemic was believed to have originated when viral transmission occurred from pig to human, thereby earning the designation, "swine flu." although pigs are thought to have been the breeding ground for the 2009 virus, sequences from bird, pig, and human viruses were all found within this newly identified virus. what is the most likely explanation of why this virus contained sequences from bird, pig, and human viruses? a) the virus was descended from a common ancestor of bird, pig, and human flu viruses.b) the infected individuals happened to be infected with all three virus types.c) related viruses can undergo genetic recombination if the rna genomes mix and match during viral assembly.d) the human was likely infected with various bacterial strains that contained all three rna viruses.