Answer:
In animals, the process of respiration is aerobic respiration, exchange of gases takes place ( carbon dioxide leaving the cell, oxygen entering)
Single cellular organisms can exchange gases directly across their cell membrane through the process o diffusion.
Large animals cannot maintain gas exchange by diffusion across their outer surface. A respiratory surface is covered with thin, moist epithelial cells that allow oxygen and carbon dioxide to exchange. Those gases can only cross cell membranes when they are dissolved in water or an aqueous solution, thus respiratory surfaces must be moist.
Explanation:
1) antigen presenting
2) release cytokines
The answer is cotton. It is natural because it is grown and easily woven in to clothes :)
<em>sieve tube elements are the cells of phloem which allow transportation of photosynthates through phloem...
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how sieve tube elements form sieve tubes:
</u>sieve tube elements are connected end to end and form a long chain which is called sieve tube,,,,
sieve tube elements are connected with the help of a side chain with the help of peptide bond...also one element has tapering end which easily overlaps with other end of next element to form sieve tube,,,,</em>
Carbon fixation.<span> A </span><span><span>\text {CO}_2<span>CO<span><span>2</span><span></span></span></span></span>C, O, start subscript, 2, end subscript</span><span> molecule combines with a five-carbon acceptor molecule, ribulose-1,5-bisphosphate (</span>RuBP<span>). This step makes a six-carbon compound that splits into two molecules of a three-carbon compound, 3-phosphoglyceric acid (3-PGA). This reaction is catalyzed by the enzyme RuBP carboxylase/oxygenase, or </span>rubisco<span>.</span>