Bone marrow is the spongy tissue inside some of the large bones. it contains immature cells, called these can develop into the red blood cells that carry oxygen through the body, the white blood cells that fight infections, and the platelets that with blood clotting.

Imagine that certain laws of physics could be ignored and you were able to travel vast distances in moments. now imagine that you traveled to an earth-like planet located light-years away that is known to support life. think about what you’ve learned in this unit and make an argument for what you think would be the dominant type of life form on this planet. consider whether a notochord is required for an organism to manipulate its environment and become a dominant creature.

What best describes emerging scientific ideas

24. how are vaccines used to keep people healthy?