Earths second atmosphere (atmosphere ii) was a thick atmosphere of primarily water vapor and carbon dioxide. what effects did this have on the earth

In the human body fibrinogen is necessary for sealing cuts and stopping the loss of blood. since fibrinogen is made of chains of amino acids it is an example of which type of organic molecule

In the water cycle , when does water undergo a chemical change

Which tool could you see a plant cell? a. a filter b. a microscope c. a microwave d. an electromagnet