A specific protein called a receptor
The answer is microscopic life appeared on Earth before flowering plants. This is because according to the label on the second box, microscopic life appeared 4.0 to 3.5 billion years ago, and this is way before the date 250 to 120 millions years ago indicated on the label on the sixth box the flowering plants appeared on Earth.
I’m pretty sure it’s D, the others don’t make sense??
A. deoxyribose + phosphate group + thymine
