Answer:
Because they do not live in the extreme environments.
Explanation:
Cell membrane has a vital role in separating the external environment of cell from its external environment. Just like eukaryotic cell, cell membrane of bacteria is also composed of proteins and lipids (phospholipids).
If we compare the structure of ancient bacteria's and modern bacteria's cell membrane then we notice that in archaebacteria or ancient bacteria the phospholipids of cell membrane are linked with ether (means they have glycerol backbones). whereas in modern bacteria they are linked through ester linkages.
So, the stronger glycerol backbones give the archaebacteria more stable cell membranes through which they are able to resist harsh environmental stresses like salt lakes, volcanic stress, boiling mud and hot springs. As modern bacteria do not always have to live under such stresses thats why they donot have ether-linked cell membrane.
Hope it helps!
<span>A.
to fuel their chemical reactions</span>
An answer might be - <span>Any of a group of complex organic macromolecules that contain carbon, hydrogen, oxygen, nitrogen, and usually sulfur and are composed of one or more chains of amino acids. Proteins are fundamental components of all living cells and include many substances, such as enzymes, hormones, and antibodies, that are necessary for the proper functioning of an organism. They are essential in the diet of animals for the growth and repair of tissue and can be obtained from foods such as meat, fish, eggs, milk, and legumes.
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B and E are the right answers. If this question is not multiple choice, I think E is the best answer.
