Plant cells have a cell wall and cell membrane but animal cell have only a cell membrane.
You can figure it out by looking at a sequence of rocks to try to decipher the times that an event occurred relative to the other events represented in that sequence. The relative age of a rock then is its age in comparison with other rocks. If you know the relative ages of two rock layers, (1) Do you know which is older and which is younger? (2) Do you know how old the layers are in years? so yeah séquences haha
1st,2nd,3rd
-Phospholipids
-proteins
-carbohydrates
