What is the difference between habitats and niche?

In the diagram below, which organelle is a ribosome, which combines amino acids and produces proteins? о

The variation among individuals, on which natural selection acts

You are given an electron micrograph of a bacterial cell. in the micrograph you can clearly see three thin layers of different densities surrounding the cell. based on the micrograph, you can infer that this cell is and would appear after application of the gram stain procedure. gram-negative / pink gram-positive / purple gram-positive / pink gram-negative / purple