Sea urchins are preyed about by many predators that inhabit their marine environment, but also those animals that don't. The main predators of the sea urchin are crabs, large fish, sea otters, eels, birds and humans.
Interphase is the phase during which the growth of the cells take place along with the metabolic activity but the nuclear division in the cell does not occur. The three stages included within the interphase are the G1, S and G2.
Genetic information is carried by: Each molecule of DNA is a double helix composed of: The four building blocks of DNA: The four building blocks of DNA are the nucleotides A, T, G, C. Each nucleotide is composed of a sugar-phosphate covalently linked to a base. The nucleotides are covalently linked together into polynucleotide chains, with a sugar-phosphate backbone.