Which of the following initiates protein synthesis in a cell by carrying specific instructions from the nucleus to the ribosomes? A. tRNA
B. mRNA
C. rRNA
D. All of above

What is the importantence of the carbon and nitretan cycles in the environment

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?