Please help! Which of the following is characteristic of all chordates but NOT found in invertebrates?

a) A circulatory system
b) A notochord
c) An exoskeleton
d) Four legs

Apaleontologist finds a plant fossil that shows that the plant had seeds. what can the paleontologist conclude?

How does upwelling affect coastal fisheries? upwelling damages nutrient supplies at coastal fisheries as the warm, nutrient-rich surface water is replaced by nutrient-poor, cold water. upwelling damages nutrient supplies at coastal fisheries as the cold, nutrient-rich surface water is replaced by nutrient-poor, warm water. upwelling improves the nutrient supply at coastal fisheries as the warm, nutrient-rich surface water replaces the nutrient-poor, cold water. upwelling improves the nutrient supply at coastal fisheries as cold, nutrient-rich water replaces the warm, nutrient-poor surface water.

The main ingredient of magma is a pahoehoe. b silca c dissolved gases d obsidian