Aprotein containing more than one polypeptide chain exhibits the level of protein structure.
a) primary
b) secondaryc) tertiaryd) quaternary
e) infinite
d) 3.14 factual recall42

the correct option is D.

Explanation:

in case of quaternary level of protein structure , protein has more than one polypeptide chains  and in this level , the polypeptide chains are aggregated and held together by hydrophobic interactions, hydrogen and ionic bonds. this specific arrangement is called the quaternary structure.for example :-

Haemoglobin the oxygen carrying protein of red blood cells, exhibits such a structure.

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.

1 digestive system

2 stomach

3 bladder

4 carbon deoxide

5 tiger