Question 1

The functional unit of the kidney is

Accepted Answer

The kidney's functional unit is the nephron, which is responsible for filtering blood and producing urine. The other options, such as ureters and the loop of Henle, are parts of the urinary system but not the functional unit of the kidney. The renal corpuscle is a part of the nephron.

Question 2

Insects maintain water and electrolyte balance through which anatomical structures?

Accepted Answer

Insects maintain water and electrolyte balance through their Malpighian tubules. These tubules actively secrete ions such as potassium and actively transport water out of the insect's body, resulting in the formation of urine. This allows the insect to regulate its internal fluid balance and prevent dehydration. Chloride cells and rectal glands are found in aquatic animals and serve similar functions, while insects do not have kidneys.

Question 3

There are microvilli on the luminal apical) surface of the epithelium that lines the lumen of the proximal tubule. Microvilli are structural features designed to

Accepted Answer

Microvilli increase the surface area of the luminal surface of the epithelium, which allows for more efficient reabsorption of solutes from the renal tubule. This is important for the kidney to maintain fluid and electrolyte balance in the body.

Question 4

Freshwater fish dilute ammonia and excrete it in a watery urine. Both freshwater and saltwater fish get rid of ammonia through diffusion across the gills. Humans convert ammonia to urea and excrete it in the urine. Birds convert ammonia to uric acid and excrete it. Why is it important for birds to get rid of ammonia?

Accepted Answer

Ammonia is toxic and can damage cells and tissues, so it is important for organisms to get rid of it. Birds convert ammonia to uric acid, which is less toxic and less water-soluble than urea or ammonia, allowing birds to excrete waste without losing too much water.

Question 5

Proper functioning of body cells and processes requires solute concentrations to be maintained within a narrow range. Which of the following solutes would be absorbed by the proximal tubule of the kidney nephron?

Accepted Answer

The proximal tubule of the kidney nephron absorbs sodium in order to regulate the body's salt and water balance. Triglyceride is a type of lipid and is not a solute that would be absorbed in the proximal tubule. Carbon dioxide is eliminated through the respiratory system and is not filtered by the kidney. Urea is a waste product of protein metabolism and is also excreted by the kidney rather than absorbed.

Question 6

Through studies on the Malpighian tubules, researchers found that K⁺accumulated on the inner face of the tubule, against its concentration gradient. What can you infer about the mechanism of transport?

Accepted Answer

The fact that K⁺ accumulated on the inner face of the tubule against its concentration gradient suggests that the movement of potassium into the lumen of the Malpighian tubules is an energy-requiring process, indicating an active transport mechanism.

Question 7

A potassium ion gradient is set up in the Malpighian tubules through an active transport process. As a result, potassium concentration is higher in the lumen of the tubules than in hemolymph. How would the potassium gradient affect water movement?

Accepted Answer

The higher concentration of potassium in the lumen of the Malpighian tubules creates a hypertonic environment. This means that there is a higher solute concentration in the lumen compared to the surrounding hemolymph. As a result, water will move by osmosis from the area of lower solute concentration (hemolymph) to the area of higher solute concentration (tubule lumen), leading to a net movement of water into the lumen of the tubules.

Question 8

Why do birds secrete uric acid as their nitrogenous waste? Because uric acid

Accepted Answer

Birds secrete uric acid as their nitrogenous waste because it requires little water for disposal, which helps conserve water and reduce body mass. This is particularly important for birds, as they need to maintain a lightweight body for flight. Uric acid is also metabolically intermediate to synthesize than other excretory products, balancing metabolic costs and water loss.

Question 9

For filtration to take place through the fenestrated capillaries of the renal corpuscle,

Accepted Answer

Filtration through the fenestrated capillaries in the renal corpuscle occurs due to the higher pressure inside the glomerulus than in the renal tubules. This pressure is created by the afferent arteriole delivering blood to the glomerulus at a higher pressure than the efferent arteriole draining blood away.

Question 10

Reabsorption of water in the hindgut of insects is controlled by which of the following?

Accepted Answer

Osmotic gradients created by ion pumps control the reabsorption of water in the hindgut of insects.

Question 11

The products of filtration in the renal corpuscle enter the renal tubule through which of the following structures?

Accepted Answer

The products of filtration in the renal corpuscle (glomerulus and Bowman's capsule) enter the renal tubule through Bowman's capsule.

Question 12

What is the organ responsible for regulating water and electrolyte balance in terrestrial vertebrates?

Accepted Answer

The kidneys are the primary organs responsible for regulating water and electrolyte balance in terrestrial vertebrates. They filter and remove waste products from the blood while also regulating the levels of various ions and water in the body. Chloride cells, Malpighian tubules, and rectal glands are all involved in regulating water and electrolyte balance in certain groups of animals, but are not the primary organs in terrestrial vertebrates.

Question 13

Figure 40.1
-Where does filtration take place in the figure above?

Accepted Answer

The answer of  Figure 40.1
-Where does filtration take place...

Question 14

Which of the following is a function of antidiuretic hormone ADH)?

Accepted Answer

ADH triggers the insertion of water channels called aquaporins, thereby increasing the amount of water reabsorbed by the collecting duct. This helps to prevent excess water loss in urine and maintain the body's water balance.

Question 15

Different habitats pose certain challenges to animal survival. For instance, terrestrial insects must maintain water balance by minimizing evaporation. How do insects minimize water loss?

Accepted Answer

Insects minimize water loss by having a cuticle covered by a waxy hydrophobic layer, which acts as a barrier to water loss through evaporation. This layer helps to seal in moisture and prevent water loss from the body. Eating more water-rich plants, excreting nitrogenous waste as urea, or keeping the spiracles open would not be effective strategies for minimizing water loss in terrestrial insects.

Question 16

In flour beetles and desert locusts, how is water conserved?

Accepted Answer

The answer of In flour beetles and desert locusts, how...

Question 17

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because

Accepted Answer

The differential permeabilities of the ascending and descending limbs of the loop of Henle are important in establishing an osmotic gradient. This allows for the concentration of urine and conservation of water in terrestrial vertebrates. A and B are incorrect because the loop of Henle's main function is water reabsorption and regulation, not detoxification or hormonal regulation. D is incorrect because additional filtration does not occur along the loop of Henle.

Question 18

How does ion composition of pre- urine differ from hemolymph?

Accepted Answer

The answer of How does ion composition of pre- urine...

Question 19

Water loss from insect surface is minimal due to which of the following structures?

Accepted Answer

Chitin and the cuticle provide a waterproof barrier that reduces water loss from the insect's surface. A small surface area/volume relationship may also help reduce water loss, but it is not as significant as the role of chitin and the cuticle. A proteinaceous epidermis and tracheae and spiracles are not directly related to water loss prevention from the surface.

Question 20

Malpighian tubules form pre- urine, which is further processed by which of the following anatomical structures?

Accepted Answer

The pre-urine produced by the Malpighian tubules is processed further in the hindgut, where water and solutes are reabsorbed to form the final urine. Option A (hemolymph) is not a structure, but rather the fluid that circulates in the open circulatory system of insects. Option B (rectal gland) is a structure found in marine animals like sharks and rays, not insects. Option C (chloride cells) are specialized cells found in the gills of aquatic animals that help regulate salt and water balance, not in the processing of insect urine.

Quiz 40: Water and Electrolyte Balance in Animals

The functional unit of the kidney is

Insects maintain water and electrolyte balance through which anatomical structures?

There are microvilli on the luminal apical) surface of the epithelium that lines the lumen of the proximal tubule. Microvilli are structural features designed to

Proper functioning of body cells and processes requires solute concentrations to be maintained within a narrow range. Which of the following solutes would be absorbed by the proximal tubule of the kidney nephron?

Through studies on the Malpighian tubules, researchers found that K⁺accumulated on the inner face of the tubule, against its concentration gradient. What can you infer about the mechanism of transport?

A potassium ion gradient is set up in the Malpighian tubules through an active transport process. As a result, potassium concentration is higher in the lumen of the tubules than in hemolymph. How would the potassium gradient affect water movement?

Why do birds secrete uric acid as their nitrogenous waste? Because uric acid

For filtration to take place through the fenestrated capillaries of the renal corpuscle,

Reabsorption of water in the hindgut of insects is controlled by which of the following?

The products of filtration in the renal corpuscle enter the renal tubule through which of the following structures?

What is the organ responsible for regulating water and electrolyte balance in terrestrial vertebrates?

Figure 40.1 -Where does filtration take place in the figure above?

Which of the following is a function of antidiuretic hormone ADH) ?

Different habitats pose certain challenges to animal survival. For instance, terrestrial insects must maintain water balance by minimizing evaporation. How do insects minimize water loss?

In flour beetles and desert locusts, how is water conserved?

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because

How does ion composition of pre- urine differ from hemolymph?

Water loss from insect surface is minimal due to which of the following structures?

Malpighian tubules form pre- urine, which is further processed by which of the following anatomical structures?

Quiz 40: Water and Electrolyte Balance in Animals

The functional unit of the kidney is

Insects maintain water and electrolyte balance through which anatomical structures?

There are microvilli on the luminal apical) surface of the epithelium that lines the lumen of the proximal tubule. Microvilli are structural features designed to

Proper functioning of body cells and processes requires solute concentrations to be maintained within a narrow range. Which of the following solutes would be absorbed by the proximal tubule of the kidney nephron?

Through studies on the Malpighian tubules, researchers found that K+ accumulated on the inner face of the tubule, against its concentration gradient. What can you infer about the mechanism of transport?

A potassium ion gradient is set up in the Malpighian tubules through an active transport process. As a result, potassium concentration is higher in the lumen of the tubules than in hemolymph. How would the potassium gradient affect water movement?

Why do birds secrete uric acid as their nitrogenous waste? Because uric acid

For filtration to take place through the fenestrated capillaries of the renal corpuscle,

Reabsorption of water in the hindgut of insects is controlled by which of the following?

The products of filtration in the renal corpuscle enter the renal tubule through which of the following structures?

What is the organ responsible for regulating water and electrolyte balance in terrestrial vertebrates?

Figure 40.1 -Where does filtration take place in the figure above?

Which of the following is a function of antidiuretic hormone ADH) ?

Different habitats pose certain challenges to animal survival. For instance, terrestrial insects must maintain water balance by minimizing evaporation. How do insects minimize water loss?

In flour beetles and desert locusts, how is water conserved?

The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because

How does ion composition of pre- urine differ from hemolymph?

Water loss from insect surface is minimal due to which of the following structures?

Malpighian tubules form pre- urine, which is further processed by which of the following anatomical structures?

Through studies on the Malpighian tubules, researchers found that K⁺accumulated on the inner face of the tubule, against its concentration gradient. What can you infer about the mechanism of transport?