Which statement best explains why the atmosphere is considered an open system? a there is no definite boundary separating it from outer space. b energy and matter can enter and leave. c its molecules can move freely, without resistance. d it can accept an unlimited amount of energy.

What do heterotrophic cells need to survive?

What are some possible short and long term medical concerns for crew members on longer space exploration trips

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.