Embryophyta is a clade within the Phragmoplastophyta, a larger clade that also includes several green algae groups. Embryophytes are the plants growing on land which include hornworts, liverworts, gymnosperms, flowering plants etc while green algae mostly thrive in aquatic environment.
The conduction of water requires vascular tissue called xylem. In green algae, it is not necessary to have water conducting tissue as the entire body is in contact with water. However in embryophytes, having a vascular tissue is an adaptation that ensures to provide water to the higher parts of the plant which is not directly in contact with the soil.
Answer: A physical change
Explanation: since the melted they are still Crayons. You can freeze it and it would still be a crayon. So it was only a physical change
Double-stranded RNA is the answer to this question that you have asked