A cell biologist compared the properties of rough endoplasmic reticulum (ER) and smooth ER. She found that one type of ER is used for protein storage, and the other is used for lipid storage. What accounts for This difference?

Sydney drew a flow chart to illustrate the nitrogen cycle. which labels best complete the flow chart? x: producers undergo photosynthesis. y: nitrogen compounds are released into the air. x: nitrogen compounds are released into the air. y: producers undergo photosynthesis. x: free nitrogen is in the atmosphere. y: producers absorb nitrogen compounds through their roots. x: producers absorb nitrogen compounds through their roots. y: free nitrogen is in the atmosphere.

Dna replication or repair occurs in a cell in all of thw following situations except when

In each transformation of energy , some energy what?