Question

question 7 (2.5 points)
birds and mammals share which characteristic?
ectothermy
air pocketed bones
bladders
four - chambered heart
three - chambered heart
question 8 (2.5 points)
the vertebral column develops from the ____
notochord
hollow, dorsal nerve cord

Explanation:

• Question 7: Birds and mammals are endotherms (not ectotherms). Only birds have air - pocketed bones. Not all mammals have bladders (e.g., some bats). Both birds and mammals have a four - chambered heart (two atria and two ventricles), which is more efficient in separating oxygenated and deoxygenated blood compared to three - chambered hearts (found in some lower vertebrates).
• Question 8: The notochord is a rod - like structure in chordate embryos. In vertebrates, the vertebral column develops from the notochord. The hollow, dorsal nerve cord develops into the central nervous system (brain and spinal cord) in vertebrates.

Answer:

Question 7: four - chambered heart
Question 8: notochord