What evidence supported the Davson-Danielli model for the cell membrane? A. Electron micrograph pictures showing a blue center surrounded by 2 layers.
B. Presence of proteins that was unaccounted for.
C. Diffusion models predicted fluid flowing into the cell at a rate consistent with their model.
D. Electron micrograph pictures showing 2 separate layers.

The answer is A

Electron micrograph pictures showing a blue center surrounded by 2 layers.

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.