BIO 172 UH Manoa Exam 2 Questions and Answers 100% Pass

BIO 172 UH Manoa Exam 2 Questions and Answers 100% Pass **What are animals characterized by?** **Animals:** Multicellular eukaryotes that are heterotrophic, lacking cell walls, and having bodies held together by structural proteins like collagen. **What is the function of collagen in animals?** **Collagen:** It makes up connective tissues, providing flexibility, high tensile strength, and elasticity. **Differentiate between skin, ligament, and tendon based on collagen arrangement.** **Skin:** Has a dense irregular arrangement of collagen fibers. **Ligament:** Contains collagen arranged in sheets, connecting bones. **Tendon:** Exhibits a cable-like arrangement of collagen, connecting muscle to bone. **Describe the formation and function of a zygote.** **Zygote:** Formed by the fusion of sperm and egg during fertilization. It undergoes rapid cell division called cleavage. **Explain the role of germ layers in animal development.** **Germ Layers:** These layers give rise to the various tissues and organs of the animal embryo. **Define blastula and gastrula in animal embryonic development.** **Blastula:** A stage where cells have undergone multiple cleavages, forming a hollow ball of cells. **Gastrula:** Forms from the gastrulation process of the blastula, developing layers of embryonic tissues. **Differentiate between ectoderm and endoderm in animal development.** **Ectoderm:** The outer germ layer covering the embryo's surface. **Endoderm:** The innermost germ layer that lines the developing digestive tube (archenteron). **Classify animals as diploblastic or triploblastic based on embryonic development.** **Diploblastic:** Animals with ectoderm and endoderm germ layers (e.g., corals, jellyfish). **Triploblastic:** Animals that additionally have a mesoderm layer between ectoderm and endoderm (e.g., bilaterians). **Define and classify bilaterians among animals.** **Bilaterians:** Refers to all multicellular animals except sponges and cnidarians, exhibiting bilateral symmetry and cephalization.