Describe an exercise circuit. List its benefits

Practice or pre-exercise theories of play pose the idea that a. play provides children with an opportunity to practice adult activities. b. play is necessary to reenergize human cognition. c. children have too much energy and play will rid them of that energy. d. children are the link between animals and human beings.

The structure shared between the male reproductive system is the

Viruses use the host's machinery to make copies of themselves. however, some human viruses require a type of replication that humans do not normally have. for example, humans normally do not have the ability to convert rna into dna. how can these types of viruses infect humans, when human cells cannot perform a particular role that the virus requires? a) the virus causes mutations in the human cells, resulting in the formation of new enzymes that are capable of performing these roles.b) the viral genome codes for specialized enzymes not in the host.c) the virus infects only those cells and species that can perform all the replication roles necessary.d) viruses can stay in a quiescent state until the host cell evolves this ability.