They breathe through their skin. Air dissolves on the mucus of their skin, so they MUST stay moist to breathe. If worms dry out, they suffocate. As fresh air is taken in through the skin, oxygen is drawn into the worm's circulatory system, and the worm's hearts pump the oxygenated blood to the head area.
Answer:
Genetics is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms. Gregor Mendel, a scientist and Augustinian friar, discovered genetics in the late 19th-century. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring.
Explanation:
A panther because it eats the primary consumer which would be the deer.
an oak tree is the producer (bottom of the food chain)
the deer is the primary consumer because it eats grass which would also be a producer
and the hawk would be the top predator because it eats a snake which would eat a mouse which would feed on a producer :)