instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: Colonial organisms were probably one of the first evolutionary steps towards multicellular organisms. Algae of the genus Volvox are an example of the bridge between colonial organisms and multicellular organisms. Each Volvox , shown in Figure above , is a colonial organism. It is made of up to 50,000 photosynthetic flagellate algae that are grouped together into a hollow sphere. Volvox live in a variety of freshwater habitats, and were first reported by Antonie van Leeuwenhoek in 1700. Answer: multicellular
answer:
Colonial organisms were probably one of the first evolutionary steps towards which type of organisms?

question:
Passage: An important function of the circulatory system is transporting oxygen to cells. Answer: circulatory system
answer:
Which system transports oxygens to cells?

question:
Passage: Observations can happen on many scales. You can use a microscope to observe tiny things. You can use a telescope to observe distant things in space. To learn about the effects of climate change, you could observe Earth's surface. How would you make observations of Earth's surface? You could do this from the land surface or from space. Many important observations are made by orbiting satellites. These satellites have a bird's eye view of how the planet is changing ( Figure below ). Answer: satellites
answer:
What man-made devices in space are used to observe the earth's surface?