Which term identifies proteins that allow muscles to shorten it lengthen

Why do we perceive objects as retaining their brightness under different lighting levels?

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?

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