There are seven types of proteins. Three of them are structural, mechanical, and nutrient. What are the other four

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.

some inherited genetic mutations can be good for the offspring, so the answer is different genetic mutations cause many forms of cancer.