Explain how yeast cells can be considered single-celled organisms when they are still connected together.

a yeast cell is a unicellular organism

Explanation:

they have a nucleus and organelles characteristic of more complex life forms. they are kind of like a plankton. they don't use cell signaling pathways like our cells would. I hope this helps. this question was a little difficult for me, but I hope I gave you enough info to help you out! :)

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

explanation:

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.