C. because stimuli is how your body responds to something, and in this case, someone's heart rate increases WHEN their blood oxygen drop. Do you see how it responds? ;-)
Answer:
They are both celestial bodies orbiting our Sun, and they both can have unusual orbits, sometimes straying close to Earth or the other planets
Carrier proteins are the proteins in active transport
The correct answers are options:
1. Amphibians evolved before land reptiles.
4. Elephants appear in the fossil record after dinosaurs became extinct.
The relative dating is a technique of dating with respect to any past event. In this case, two events are discussed to be occurred in a sequence related to one-another. In the option 1, the amphibians are said to be evolved before reptiles. So, the evolution of the amphibians is relatively dated with the evolution of reptiles. Same in the option 4, the evolution of the elephants is relatively dated with the extinction of the dinosaurs.
