Excretion In Animals & Plants - 2 - Class 10

The three basic renal processes are glomerular filtration, tubular reabsorption, and tubular secretion. The blood is filtered in the Bowman's capsule due to the high hydrostatic pressure by a process known as ultrafiltration. The glomerular filtrate when passes through the convoluted tubules, the useful components present in the filtrate is reabsorbed by tubular reabsorption. Tubular secretion (movement from the peritubular capillaries into the tubules) is a pathway in addition to glomerular filtration for a substance to gain entry to the tubule.
So, the correct answer is option A.

Anuria occurs when the kidneys aren't producing urine. A person may first experience oliguria, or low output of urine, and then progress to anuria. 

The carbon dioxide is excreted out from the body through its moist skin by the process of diffusion. The nitrogenous wastes are excreted out of the body by special excretory organs called nephridia.

Urea is produced in the liver and is metabolite of amino acids. Ammonium ions are formed in the break down of smino acids. Some are used in the Biosynthesis of nitrogen compounds. Excess ammonium ions are converted to urea. 

The right ventricle pumps blood from the right atrium to the pulmonary artery. The pulmonary artery sends the deoxygenated blood to the lungs, where it picks up oxygen in exchange for carbon dioxide.

To urinate, the brain signals the muscular bladder wall to tighten, squeezing urine out of the bladder. At the same time, the brain signals the sphincters to relax. As the sphincters relax, urine exits the bladder through the urethra.

Elasmobranchii and Adult Amphibians live in sea water which is hypertonic to them. They need to conserve water thus excrete urea. The urea also acts as Osmoregulator for Adults  Amphibians and Elasmobranchii. To maintain their water balance, Elasmobranchii and adult amphibians drink large quantities of sea water, retaining most of the water and excreting the salt. 

Uric acid passes through the liver, and enters your blood stream. Most of it is excreted in your urine, or passes through your intestines to regulate " Normal" Levels. 

The given information states that different animals excrete different nitrogenous wastes. Let's analyze the options and determine the correct answer.
A: There is no uniform pattern of removal of nitrogen wastes.
This option is not correct because there is a pattern observed in the excretion of nitrogenous wastes among different animals.
B: Aquatic and land animals excrete urea.
This option is not correct because although some land animals excrete urea, not all aquatic animals excrete urea. For example, birds and insects excrete uric acid, which is not urea.
C: Animals that fly excrete uric acid.
This option is not correct because although birds, which are animals that fly, excrete uric acid, not all animals that fly excrete uric acid. For example, lizards and snakes also excrete uric acid, but they do not fly.
D: Nitrogen waste excretion is closely related to the availability of water in the environment.
This option is correct because the given information mentions that animals like crocodiles and alligators, which excrete ammonia, are aquatic animals. Ammonia is highly toxic and requires a lot of water for dilution and excretion. Therefore, the excretion of nitrogenous waste is closely related to the availability of water in the environment.
Hence, the correct answer is option D: Nitrogen waste excretion is closely related to the availability of water in the environment.

The white matter in a bird's dropping is uric acid. Here's a detailed explanation:
Definition of Bird Dropping:
Bird droppings, also known as bird poop or bird guano, are the excrement or feces of birds. They consist of various components, including uric acid.
Composition of Bird Droppings:
Bird droppings are composed of three main components:
1. Feces: The solid waste material produced by the bird's digestive system.
2. Uric Acid: A white, paste-like substance that is the waste product of protein metabolism in birds. It is insoluble in water, which allows birds to conserve water by excreting it in a concentrated form.
3. Urates: These are salts of uric acid and are also present in bird droppings.
Identification of the White Matter:
The white matter in a bird's dropping refers to the uric acid component. It is the main reason for the characteristic white color of bird droppings. The uric acid is excreted by the bird's kidneys and mixed with other waste materials before being expelled from the body.
Functions of Uric Acid:
Uric acid serves several functions in birds:
- It helps birds conserve water by excreting nitrogenous waste in a highly concentrated form.
- It plays a role in maintaining the bird's acid-base balance.
- It helps to regulate the bird's body temperature by reducing water loss through evaporation.
Therefore, the white matter in a bird's dropping is uric acid, which is responsible for the white color and characteristic appearance of bird droppings.

Regulation of Water and Salts by Kidneys:
The kidneys play a crucial role in regulating the balance of water and salts in the body. Here is a detailed explanation of how the kidneys effectively regulate these two substances:
1. Water Regulation:
- The kidneys control the amount of water in the body by adjusting the volume of urine produced. This process is regulated by the hormone called antidiuretic hormone (ADH).
- When the body is dehydrated, the pituitary gland releases ADH, which signals the kidneys to reabsorb more water from the urine back into the bloodstream.
- On the other hand, when the body has excess water, ADH secretion decreases, leading to increased urine output and elimination of excess water from the body.
2. Salt Regulation:
- The kidneys regulate the concentration of salts, such as sodium, potassium, and chloride, in the body. This is important for maintaining proper fluid balance, nerve function, and blood pressure.
- The process of salt regulation primarily occurs in the nephrons, the functional units of the kidneys. The nephrons filter the blood, reabsorb essential substances, and excrete waste products.
- The reabsorption and excretion of salts are controlled by various hormones, including aldosterone and angiotensin II. These hormones act on specific receptors in the nephrons to regulate the movement of salts in and out of the bloodstream.
In conclusion, the kidneys effectively regulate the balance of water and salts in the body, ensuring proper hydration, electrolyte balance, and overall homeostasis.

Function(s) of the liver in excretion:
- Deamination and urea formation: The liver plays a crucial role in the metabolism of amino acids. It removes the amino group (-NH2) from amino acids through a process called deamination, converting them into ammonia (NH3). The liver then combines ammonia with carbon dioxide to form urea, which is less toxic and can be safely excreted in urine by the kidneys.
- Elimination of haemoglobin and bile salts: The liver is responsible for breaking down old and damaged red blood cells. During this process, the haemoglobin component of these cells is converted into bilirubin, a waste product. The liver then conjugates bilirubin with other substances to form bile salts, which are excreted into the bile and eventually eliminated from the body through feces.
- Inactivation of chemicals after their role is over: The liver plays a crucial role in the detoxification and inactivation of various substances, including drugs, alcohol, and environmental toxins. It accomplishes this through a series of enzymatic reactions that modify these substances into less harmful or more easily excretable forms.
Therefore, all of the mentioned functions (deamination and urea formation, elimination of haemoglobin and bile salts, inactivation of chemicals after their role is over) are performed by the liver in excretion. Hence, the correct answer is D: All the three mentioned above.

Active transport can be seen in the kidneys, at the Reabsorption stage in the nephrons. Along the nephron, a large network of capillaries surround the tubules that carry the waste. Substances that the body needs from the waste that can be
 re- used  are  reabsorbed into the blood stream.

The renal artery enters the Bowman's capsule and forms a tuft of capillaries which helps in ultrafiltration. The renal artery carries blood to the kidney, while the renal vein carries blood, with much lower concentration of urea and mineral ions, away from the kidney.

Removal of undigested food is called egestion and removal of unwanted toxic substances like urea is called excretion. Both are different phenomena carried out by different organs.

Amoeba has a contractile vacuole as an excretory organ that gathers the excretory wastes delivered inside the cell.These waste materials are discharged out by the procedure of dispersion through the general body surface. In the single adaptable cell, contractile vacuoles additionally assume some part in the expulsion of waste materials.

Plant gets rid of excess water by transpiration.

• Definition: Transpiration is the process by which plants release water vapor through their leaves.


• Function: It helps in the regulation of water content and temperature in plants.


• Process: Transpiration occurs through small openings on the surface of leaves called stomata. These stomata open and close to control the release of water vapor.


• Factors affecting transpiration:
  
  
  
  • Temperature: Higher temperatures increase the rate of transpiration.
  
  
  • Humidity: Lower humidity levels promote faster transpiration.
  
  
  • Wind: Increased air movement increases the rate of transpiration.
  
  
  • Light: Intense light stimulates stomatal opening and increases transpiration.
  
  
  
  


• Importance:
  
  
  
  • Water transport: Transpiration helps in the upward movement of water from the roots to the leaves.
  
  
  • Nutrient absorption: It facilitates the absorption of minerals and nutrients from the soil.
  
  
  • Cooling effect: Transpiration cools down the plant and prevents overheating.
  
  
  • Turgor pressure: It maintains turgor pressure in plant cells, which is essential for support and structure.
  
  
  
  


• Difference from respiration and photosynthesis:
  
  
  
  • Respiration: Respiration is the process by which plants and animals convert glucose into energy. It occurs in all living cells.
  
  
  • Photosynthesis: Photosynthesis is the process by which plants convert sunlight, carbon dioxide, and water into glucose and oxygen. It occurs in the chloroplasts of plant cells.
  
  
  
  

Therefore, the correct answer is C: Transpiration.

The waste products of a plant are carbon dioxide, water and oxygen. While carbon dioxide and water vapour are waste products of respiration, oxygen is a waste product of photosynthesis. 

Plants produce carbon dioxide and water as respiratory waste products. In green plants, the carbon dioxide released during respiration gets utilised during photosynthesis. Oxygen is a waste product generated during photosynthesis and exists through stomata, root cellar Walls and other routes. Plants can get rid of excess water by transpiration and guttation.

Plants need to excrete excess carbon dioxide and oxygen. Carbon dioxide is a waste product of aerobic respiration in plant cells. Oxygen is a waste product of photosynthesis .

Lenticles are holes or pores like stomata present in bark or stem of plant.So exchange of gases or gaseous wastes of respiration are reoved through both stomata and lenticles

To determine the correctness of the given statements, let's analyze each statement one by one:
A: Gum are found in babul tree
- Gum is indeed found in the babul tree.
- This statement is correct.
B: Leaves of tulsi contain essential oils
- Tulsi leaves do contain essential oils.
- This statement is correct.
C: Leaves of amla and tea contain tannins
- Both amla and tea leaves contain tannins.
- This statement is correct.
D: All of the above
- Since all three statements (A, B, and C) are correct, the statement "All of the above" is also correct.
Therefore, the correct answer is D, i.e., All of the above.