The alveoli needs of the epithelium for the gaseous exchange and stratified squamous epithelium are formed of multiple layers the difficulty in a gaseous exchange
Pure breeding means the same as selective breeding since you take two animals and combine their traits for certain reasons
Answer: X: transcription
Y: messenger
Explanation: Transcription is a process by which genetic information in a DNA is copied into a messenger RNA.
Transcription takes place in the nucleus and it is catalyzed by an enzyme called RNA polymerase. The messenger RNA produced from transcription then leaves the nucleus to the ribosome where it serves as a template for protein synthesis.