1. Categorize the following animals based on the nature of excretion of nitrogenous waste.
Mammals, Bony fishes, Birds, Aquatic amphibians, Insects, Cartilage fishes, Aquatic insects
2. In an informal discussion in your class, your friend made a comment that “Malpighian tubules are the kidneys of a cockroach.” How will you evaluate this statement?
1. Analyse the graph:
a. What is the relationship between the amount of vasopressin in blood plasma and the blood volume? (1)b. Suggest a situation in which the vasopressin decreases in the blood. (1)
1. Observe the figure. No need to redraw the figure. Label A and B and write the function of A and B.
1. a) Prepare a flowchart of filtrate flow in the nephron using the flow terms. (1)
Collecting duct, PCT, DCT, Ascending limb of Henle’s loop, descending limb of Henle’s loop, Bowman’s capsule
b) Counter current system plays an important role in concentrating urine. Name any two regions inside the kidney, where the counter current system is seen. (1)
1. Complete each of the following sentences using appropriate words. (4 x ½=2)
a. Ascending limb of Henle’s loop is ………… to water whereas the descending limb is …………… to water.
b. An excessive loss of fluid from the body stimulates the hypothalamus to release ………. hormone from ………
1. Identify the odd one and write the common features of the other items.
Nephridia, Malpighian tubules, Spicules, Kidney, Flame cells (1)
2. How the counter current mechanism helps to maintain the concentration gradient in the medullary interstitium? (2)
3. On a hot day would you expect your level of ADH in blood to be high or low? Explain. (2 score)
1. In a biology class related to excretion in the human body, a student gave an opinion that in every minute about 2% of the total blood volume of the body is converted to GFR whereas only 1% of this GFR is eliminated as urine. Evaluate this opinion and substantiate your answer. (2)
1. Observe the schematic diagram showing the mechanism for regulating blood volume.
a. Fill the gap in the diagram. (½)
b. Illustrate how blood volume is regulated by this system. (1½)
1. The output of urine increases in clod days while decreases in hot and sunny days. Can you give a reason for this phenomenon as realized from the graph given below? (2)
1. A diagrammatic representation of a nephron is given.
a. Identify the parts labeled as X and Y.
b. Which part/parts of a nephron constitute the Malpighian body? (1+1=2)