Question 14 Which of the following statements is true about the effects of exercise, physical activity, or
meditation on the functions of the brain?
Regular physical activity increases the risk of dementia and depression.
Meditation hastens the otherwise gradual loss in gray matter.
Regular physical activity protects against cognitive decline.
Exercise inhibits the release of neurotransmitters that elevate moods.
Strenuous exercise inhibits the release of endogenous opioids.

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.