Blood moves into and then out of a heart chamber because 1. the veins and arteries constrict and dilate to propel and attract blood. 2. it moves along its pressure gradient, and that gradient depends on contraction and relaxation during the cardiac cycle. 3. it is under constant pressure, but its movement is dictated by the control of valve openings and closures. 4. All of the choices are correct.

Texas has an impending storm, and california is experiencing a water crisis. match the technologies with the state that can use them to reduce the effects eddies natural hazards. texas is the storm cellar and the wood that is crisscrossed. california is the dam and the storage tanks

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.

The picture showed normal blood cells which are around and sickle cells which appear much longer people with sickle-cell suffer from the sickle cell anemia which is inherited diseaseit is caused by a change in gene responsible for production of hemo goblin this type of change is known as an