<span>How many openings are in the digestive system of flatworms? Answer: 1
Flatworms digestive system is called 2-way which mean the same opening is used for eat and removing waste. That's why it only has one opening. Human system is one way since we eat from the mouth and remove waste from the anus.</span>
Lichens and algae I believe
Answer:
Cactus plants are able to survive in drier environment because they are able to store water for long periods.
B causes all vegetation to freeze
Protocells are self-organized, spherical collection of lipids. This is the proposed as the stepping stone to the origin life. One of the important qualities of protocells is its self-replicating, using the amphiphilic molecules. This requires repeatable set of chemical events.