Asequence of dna responsible for coding a protein?

Crossing over is a method of (blank)?

Which of the following is a true statements about viruses? viruses have no nucleus. viruses are alive. viruses have a cell membrane. all viruses are deadly.

Brian has a medical condition called cone dystrophy, which is a disorder of the cone cells in the eye. what symptoms would you expect brian to have? a. inability to see in the dark b. difficulty determining colors c. difficulty determining shapes and outlines d. inability to see in all light conditions