Which Statement correctly Describes The Muscular System of a flatworm

A. All of the muscles are attached to a center bone

B. It is made up of two layers of muscle

C. It is made up of three types of muscle tissue

D. All of the muscles are involuntary muscles

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

What is it called when lava when it erupts from the surface through volcanoes.

Fungi exist as single cells or as branching networks of multicellular filaments. how does the structure of filaments relate to their function