What is the closest living relative clade to the bird clade?

Of the species listed below, which of these is the earliest species in the genus Homo?

What is the most numerous and diverse of all vertebrates?

If a pollutant, like DDT, is eaten by zooplankton in the sea, that are then consumed by small fish, that are consumed by larger fish, that are consumed by eagles. This causes the concentration of DDT in the blood of these animals to get higher as you work our way up the food chain. This is an example of:

Platyhelminthes have an incomplete digestive system. What is the main structure of their digestive system?

What kind of animals are in Phylum Cnidaria?

turtles in ponds(1).png Which pond has the higher relative abundance?

Which of these is NOT one of the conservation ethics?

population pyramid.png Given this population pyramid, what is NOT true about this population?

Why are changes in the global carbon cycle important?