<span>The immune system is the body's natural defense mechanism against organisms that can cause infection.There are three types of mechanisms:
1. Cellular :</span><span> refers to the recognition and/or killing of virus and virus-infected cells by leukocytes and the production of different soluble factors (cytokines) by these cells when stimulated by virus or virus-infected cells
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2. Structural: </span>barriers and the immune system defend the body<span> against organisms that can cause infection. </span>Natural<span> barriers include the skin, mucous membranes, tears, earwax, mucus, and stomach acid.
3. Chemical: </span><span>Some of these include the low pH of the stomach, which inhibits the growth of pathogens; blood proteins that bind and disrupt bacterial cell membranes; and the process of urination, which flushes pathogens from the urinary tract.
</span><span>antibodies - chemical
tissues lining hollow organs - cellular
phagocytes - cellular
skin - structural
antigen - chemical
leukocytes - cellular</span>
Answer:
Option (b).
Explanation:
Iguana and flying dragons are both reptiles. Iguana is a herbivorous lizard belongs to the order squamata. Flying dragons are known as gliding lizrds and belong to the genus<em> Draco. </em>
Iguana can easily be identified by their droopy skin, stocky stature and spines on their necks, backs, heads and tails. Iguanas may venture to the ground. Flying dragons has reduced tail, throat sacs color is different in males and females. Flying dragons used to live on trees, feed on the arboreal ants and will frequently venture in the ground.
Thus, the correct answer is option (B).
Protects brain and spinal cord from trauma, as well as supplies nutrients to nervous system tissue. It also removes waste from cerebral metabolism.
