Answer: Option A. -> Henle's loop
:
A
In the kidney, the loop of Henle is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. The main function of loop of Henle is to create a concentration gradient in the medulla of the kidney

Answer: Option D. -> When someone drinks a lot of water, ADH release is suppressed
:
D
Antidiuretic hormone (ADH) or vasopressin increases the reabsorption of water in the distal convoluted tubule, collecting tubules and collecting ducts of the nephrons in the kidneys. As a result, the reabsorption of water from the glomerular filtrate is increased. When someone drinks alot of water, requirement of absorption of water decreases, so ADH release is suppressed.

Answer: Option A. -> Micturition will be uncontrolled.
:
A
Sensory stretch receptors are responsible for stretch reflex. If these are removed then there will be no more autonomic nervous control and urge to micturition will be uncontrolled. Micturition is the expulsion of urine from the urinary bladder.

Answer: Option C. -> Ultrafiltration, tubular reabsorption and tubular secretion
:
C
Urine formation in humans takes place by three processes - ultrafiltration, tubular reabsorption and secretion. It takes place in the Malpighian corpuscle, Henle’s loop PCT and DCT.Blood is filtered so finely through the membranes of bowman's capsule, that almost all the constituents of the plasma except the proteins pass onto the lumen of the Bowman’s capsule. Therefore, it is considered as a process of ultra filtration.A comparison of the volume of the filtrate formed per day (180 litres per day) with that of the urine released (1.5 litres), suggest that nearly 99 per cent of the filtrate has to be reabsorbed by the renal tubules. This process is called reabsorption. The tubular epithelial cells in different segments of nephron perform this either by active or passive mechanisms.During urine formation, the tubular cells secrete substances like $H^{+}$, $K^{+}$ and ammonia into the filtrate. Tubular secretion is also an important step in urine formation as it helps in the maintenance of ionic and acid-base balance of body fluids.

Answer: Option A. -> Maintaining a high osmotic pressure in the tissues between the tubules.
:
A
The flow of filtrate in the two limbs of Henle’s loop is in opposite directions and thus forms a counter current. The flow of blood through the two limbs of vasa recta is
also in a counter current pattern. The proximity between the Henle’s loop and vasa recta, as well as the counter current in them help in maintaining an increasing osmolarity towards the inner medullary interstitium.

Answer: Option C. -> C
:
C
On the basis of nitrogenous metabolic wastes, the animals are of four types
(i) An ammonotelic organism excretes nitrogenous waste as soluble ammonia. Most of the aquatic animals including protozoans, crustaceans,platyhelminths,cnidarians, poriferans,echinoderms, fishes,larvae/tadpolesof amphibians are ammonotelic.
(ii) A ureotelic organism excretes excess nitrogen as urea -for example, frog, toad and mammals.
(iii) Uricotelic excrete nitrogen in the form of uric acid – for example, insects, land reptiles and birds.

Answer: Option B. -> Faeces
:
B
Bilirubinis a highly insoluble antioxidant produced by the metabolism of heme. It is derived mostly from senescent red blood cells and circulates with albumin.Bilirubinand its metabolites provide colour to the bile, faeces, and urine. These waste products reach the duodenum and pass out with faeces.

Answer: Option C. -> Blood enters glomerulus through efferent arterioles 
:
C
Blood enters in glomerulus through afferent arterioles and theefferent arteriolecarries blood away from the glomerulus. Because it has a smaller diameter than theafferent arteriole, it creates some resistance to blood flow, producing the back-up of blood in the glomerulus which creates higher pressure in the glomerular cavity.

Answer: Option B. -> Glomerulus and the Bowman’s capsule of the nephron
:
B
Theglomerulusis surrounded by a cup-like sac known as Bowman's capsule. Thebloodplasma isfilteredthrough the capillaries of theglomerulusinto the capsule.
TheMalpighian tubulesystem is a type of excretory and osmoregulatory system found in some insects, myriapods, arachnids, and tardigrades.
Nephridiaremove metabolic wastes from an animal's body. They are present in many different invertebrate organisms.
Thecollecting ductis the last part of a long, twisting tube that collects urine from the nephrons

Answer: Option A. -> Bowman's capsule→Proximal tubule→ Loop of Henle→Distal tubule→Collecting duct
:
A
The following is the order of flow of fluid:

1. Bowman's Corpuscle - The nephron begins as a blind, cup-like pocket called Bowman's capsule. The capsule envelopes a bundle of capillaries called the glomerulus. Bowman's capsule and glomerulus make up the renalcorpuscle.


2. Proximal convoluted tubule - is the longest and widest segment of the nephron.


3. Loop of Henle - The cells of the descending limb of the loop are simple squamous and give this region of the tubule a narrow diameter.


4. Distal convoluted tubule - Following the loop, the nephron continues as the distal tubule.


5. Collecting duct -Collecting duct is a long, straight tube where the maximum reabsorption of water takes place to produce concentrated urine.