What are Some of the characteristics that vertebrates share( choose all that apply) 1. Highly developed senses and nervous systems
2. Endoskeletons and a backbone
3. External protective structures
4. Joint appendages

List the advantages and disadavantages of the switch from persistent chlorinated hydrocarbon pesticides (such as ddt) to nonpersistent organophosphate pesicides. have the benefits of the switch outweighed the disadvantages? explain.

What are some possible consequences of preventing prescribed burns and natural wildfires

Which of the following is a reason why early living organisms on earth could not have survived on the surface? 1. the lack of an ozone layer 2. the lack of oxygen in the atmosphere 3. the fact that these organisms were single-celled