Answer:
B. Is the answer. They are losing their habitat and therefore will be more likely to go extinct 
 
        
                    
             
        
        
        
<h2><u>
Heart and lungs:</u></h2>
The upper chamber of the heart is called atrium and lower chamber of the heart is called ventricles.
The blood circulation in the heart is basically under the functioning of three blood vessels namely:
<h3><u>Arteries:
</u></h3>
- They start with the aorta, the huge vein leaving the heart. 
 - Veins divert oxygen-rich blood from the heart to the majority of the body's tissues. 
 - They branch a few times, decreasing and littler as they convey blood more remote from the heart.
 
<h3><u>Capillaries:
</u></h3>
- These are little; flimsy blood vessels that associate the arteries and the veins.
 - Their dainty dividers permit oxygen, supplements, carbon dioxide, and other waste items to go to and from our organ's cells.
 
<h3><u>Veins:
</u></h3>
- These are the blood vessels that return blood to the heart; this blood needs (oxygen-poor) and is wealthy in waste items that are to be discharged or expelled from the body.
 - Veins become bigger and bigger as they draw nearer to the heart.
 - The unrivaled vena cava is the huge vein that brings blood from the head and arms to the heart, and the second rate vena cava brings blood from the mid-region and legs into the heart.
 
 
        
             
        
        
        
Answer:
The correct answer is option A. "They only introduce supercoiling and cannot relax a covalently closed circular DNA".
Explanation:
Type II topoisomerases are enzymes that regulate the winding an unwinding of DNA during DNA replication. Basically, these enzymes are the scissor that remove the knots and tangles formed during the replication process. Is false to affirm that type II topoisomerases only introduce supercoiling and cannot relax a covalently closed circular DNA. Bacterial type II DNA topoisomerases  work with the circular DNA of bacterium by changing the linking number of circular DNA by ±2.
 
        
             
        
        
        
Answer:
Polypeptide
Explanation:
Amino acids are the building block and simplest unit of protein molecules. The structural composition of each amino acids is made up of an amine group (-NH2), a carboxylic acid group (-COOH), a hydrogen atom (H) and a R side chain that differentiates every amino acid from one another. 
In a reaction process called condensation, amino acids are chemically joined together via the amine group of one and the carboxylic group of another. This process releases water molecule (H20) to form a bond called PEPTIDE bond between the amino acids. Several amino acids in their 100’s or 1000’s that are chemically joined this way forms a POLYPEPTIDE chain, which in turn forms the protein molecule.