Select all the factors that you know from the material presented in this lesson that are true of sickle cell anemia. It is an example of a single-gene disorder. It occurs in both males and females. Its gene is found on the X chromosome. It is passed down from both parents. It interferes with proper breathing and digestion. It involves the red blood cells. It is sometimes treated with blood transfusions.

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.

several tissues working together form an organ, and several organs together make up an organisms.

the group of cell that carries out special jobs are tissue.