Answer:
water-vascular system
Explanation:
Echinoderms exhibit several unique features and the presence of a water vascular system is one of them. The water vascular system of these organisms consists of a network of fluid-filled canals and chambers. The marine water enters and exits the system through an opening. This system functions as a hydrostatic skeleton during locomotion.
Tube feet of these organisms are filled with fluid as water enters into them via the canals of the water vascular system lead to them. This inflates the tube feet and serve in locomotion. The water entering through the water vascular system also brings in dissolved oxygen and food particles into the body.
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Here I provide you some examples of modified stems:
<u>Bulb:</u> discoid stems that have a single apical bud surrounded by numerous cataphiles, and in their part I have adventitious roots. Its function is the reserve.
<u>Tuber</u>: They are portions of stems with irregular growth, which forms tuberosities due to the large accumulation of reserve substances.
<u>Cladodes: </u>are flattened stems, very thick, green leaves look alike and have photosynthetic function.
<u>Stem tendrils:</u> they are filamentous stems, which can be rolled up so that the plant can climb grasped of various objects, which is useful when the plant needs to look for the greatest possible luminosity, especially in areas where shadows predominate.
Phylloclades: Stems sheet form with limited growth, like a leaf, green and photosynthetic color.
Glucagon - stored in the pancreas
Your answer to this question is c.
