What substances move freely through the shell of the egg?

The correct answer is gases oxygen and carbon dioxide, which diffuse freely across the shell of an egg.  

The four specialized membranes of the amniotic egg are amnion, chorion, yolk sac, and allantois. The chorion and the allantois exchange gases between the embryo and the air. Oxygen and carbon dioxide diffuse freely across the shell.  

An eggshell refers to the outer covering of a hard-shelled egg and of some kinds of eggs with soft outer coats. The shells of the amniotic eggs are calcareous, formed of calcium carbonate.  

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave