Answer:All organisms need four types of organic molecules: nucleic acids, proteins, carbohydrates and lipids; life cannot exist if any of these molecules are missing.
Nucleic Acids. The nucleic acids are DNA and RNA, or deoxyribonucleic acid and ribonucleic acid, respectively. ...
Proteins. ...
Carbohydrates. ...
Lipids.
Explanation:
 
        
             
        
        
        
The charactistics that make it difficult for endangered species to rebound include;
- The habitat is significantly changed
- Over exploitation of the species
- Pollution that threatens the existence of the species
<h3>What are endangered species?</h3>
Endangered species are those species that are facing the threat of extinction sometimes owing to severe habitat loss or some other factors.
We must note that these characteristics that make it difficult for endangered species to rebound;
- The habitat is significantly changed
- Over exploitation of the species
- Pollution that threatens the existence of the species
Learn more about endangered species: brainly.com/question/12446045
 
        
             
        
        
        
Answer:
DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects. Which of these would have prevented this evolution of DDT resistance in insect pests?
What would have prevented the evolution of DDT resistance in insect pests is the None of the insect pests would have genetic variations that resulted in DDT resistance. 
Explanation:
 
        
             
        
        
        
If it hits a single atom, a "product" can be broken. But only until it is a single molecule will a "molecule" be separated. Of starters, oxygen, H2O, always appears like oxygen in millions. But if you split it into smaller and lesser parts, say half, you can divide it only until you get 2 hydrogen and 1 oxygen. It's no longer water if you divide it further. It's going to be another matter. 
<em>Hope this helps!</em>