Unit 11 Homeostasis Short Questions
Q.1 What are the major organs involved in homeostasis in human body? State the role of each organ?
Q.2 What is Bowman’s capsule?
Q.3 Define Homeostasis. OR What is homeostasis. Give an example.
Q.4 Define osmoregulation.
Q.5 Define thermoregulation.
Q.6 Define Excretion.
Q.7 Differentiate between transpiration and Guttation.
Q.8 What are Hydrophytes?
Q.9 What are Xerophytes?
Q.10 What are Halophytes?
Q.11 What is Hilus?
Q.12 What are Renal Pyramids?
Q.13 What is Renal pelvis?
Q.14 What is renal corpuscle?
Q.15 What is Glomerulus?
Q.16 Define renal tubule.
Q.17 What do you know about proximal convoluted tubule?
Q.18 What is Loop of Henle?
Q.19 What is distal convoluted tubule?
Q.20 What are collecting ducts?
Q.21 What is a nephron?
Q.22 What is pressure filtration?
Q.23 What do you know about selective reabsorption?
Q.24 What is the tubular secretion?
Q.25 What is lithotripsy.
Q.26 Define dialysis.
Q.27 What is a dialyzer?
Q.28 What is peritoneal dialysis?
Q.29 What is Haemodialysis?
Q.30 What is glomerulus filtrate?
Q.31 What are papillary ducts?
Q.32 What are ureters?
Q.33 What is urethra?
Q.34 What is urinary bladder?
Q.35 What is urinary system?
Q.36 Why transpiration does not take place at night?
Q.37 What do you mean by kidney stone?
Q.38 What is guttation? How does it differ from dew?
Q.1 What are the major organs involved in homeostasis in human body? State the role of each organ?
Answer:
Human beings have highly developed organs for homeostasis which are:
(i) Lungs
Lungs remove excess carbon dioxide and keep it in balance.
(ii) Skin
Skin performs role in maintenance of body temperature and also removes excess water and salts..”
(iii) Kidneys
Kidneys filter excess water, salts, urea, uric acid etc. from the blood and form urine.
Q.2 What is Bowman’s capsule?
Answer:
One end of the renal tubule is blind and attains a cup shaped structure called Bowman’s capsule that encloses glomerulus.
Q.3 Define Homeostasis. OR What is homeostasis. Give an example.
Answer:
Homeostasis may be defined as the maintenance of the internal conditions of body in equilibrium, despite changes in the external environment e.g. the core temperature of human body remains at about 37ยฐC despite fluctuations in the surrounding air temperature.
Q.4 Define osmoregulation.
Answer:
It is defined as the maintenance of the amounts of water and salts in body fluids i.e., blood and tissue fluids:
Q.5 Define thermoregulation.
Answer:
The maintenance of internal body temperature is called thermoregulation e.g., human body temperature is kept constant at 37ยฐC.
Q.6 Define Excretion.
Answer:
The process by which metabolic wastes are eliminated from body to maintain the internal conditions at equilibrium is called excretion e.g., urea, salts of uric acid and water are eliminated out of body through excretion.
Q.7 Differentiate between transpiration and Guttation.
Answer:
Transpiration
i. It is defined as loss of water from plants surface in the form of vapours.
ii. It occurs through stomata.
Guttation
i. It is defined as appearance of drops of water on the tips or edges of leaves.
ii. It occurs through special pores called hydathodes present at leaf tips or edges.
Q.8 What are Hydrophytes?
Answer:
Hydrophytes are the plants which live completely or partially submerged in fresh water e.g. water lilly.
Q.9 What are Xerophytes?
Answer:
Xerophytes live in dry environment e.g. cacti.
Q.10 What are Halophytes?
Answer:
The plants living in sea water and adapted to salty environments are called halophytes e.g. different sea grasses.
Q.11 What is Hilus?
Answer:
The concave side of kidney faces vertebral column. There is a depression called hilus, near the centre of the concave area of kidney. This is the area of kidney through which ureter leaves kidney and other structures including blood vessels, lymphatic vessels and nerves enter and leave kidney.
Q.12 What are Renal Pyramids?
Answer:
Renal medulla consists of several cone–shaped areas called renal pyramids.
Q.13 What is Renal pelvis?
Answer:
Renal pyramids project into a funnel–shaped cavity called renal pelvis which is the base of ureter.
Q.14 What is renal corpuscle?
Answer:
The part of nephron which is not tubular and has two parts:
(i) Glomerulus
Q.15 What is Glomerulus?
Answer:
Glomerulus is a network of capillaries and is enclosed by a cup shaped structure called Bowman‘s capscule. .
Q.16 Define renal tubule.
Answer:
Tubular part of nephron which starts after Bowman‘s capsule is called renal tubule. It is sub divided into following parts:
i. Proximal convoluted tubule
ii. Loop of Henle
iii. Distal convoluted tubule
Q.17 What do you know about proximal convoluted tubule?
Answer:
First portion of renal tubule is called proximal convoluted tubule.
Q.18 What is Loop of Henle?
Answer:
U–shaped part of renal tubule is called Loop of Henle. 11.
Q.19 What is distal convoluted tubule?
Answer:
Last portion of renal tubule is called distal convoluted tubule.
Q.20 What are collecting ducts?
Answer:
The distal convoluted tubule of many nephrons open in a single collecting duct. Many collecting ducts join together to form several hundred papillary ducts which drain into renal pelvis.
Q.21 What is a nephron?
Answer:
The functional unit of the kidney is called nephron. There are over one million nephrons in each kidney.
Q.22 What is pressure filtration?
Answer:
The first step of urine formation is pressure filtration. When blood enters the kidney via the renal artery it goes to many arterioles, and then to the glomerulus. The pressure of blood is very high and so most of the water, salts, glucose and urea of the blood is forced out of glomerular capillaries.
Q.23 What do you know about selective reabsorption?
Answer:
It is the second step of urine formation. In this step, about 99% of the glomerular filtrate is re absorbed into the blood capillaries surrounding renal tubule. It occurs through osmosis, diffusion and active transport
Q.24 What is the tubular secretion?
Answer:
The third step of urine formation is called tubular secretion. Different ions, creatinine, urea etc. are secreted from blood into the filtrate in renal tubule. This is done to maintain blood at a normal pH (7.35 –7.45).
Q.25 What is lithotripsy.
Answer:
It is the method to remove kidney stones. In this method, non–electrical shock waves from outside are bombarded on the stones in the urinary system. Waves hit the dense stones and break them. Stones become sand like and are passed through urine.
Q.26 Define dialysis.
Answer:
Dialysis means the cleaning of blood by artificial ways by using a dialyzer. It is of two types: (i) Peritoneal Dialysis (ii) Haemodialysis
Q.27 What is a dialyzer?
Answer:
In haemodialysis, patient‘s blood is pumped though an apparatus called dialyzer. It contains long tube, the walls of which act as semi–permeable membranes. Blood flows through the tubules and during this extra water and wastes move from blood into the dialysis fluid.
Q.28 What is peritoneal dialysis?
Answer:
In this type of dialysis, the dialysis fluid is pumped for a time into the peritoneal cavity which is the space around gut. This cavity is lined by peritoneum. Peritoneum contains blood vessels. When dialysis fluid is placed in peritoneal cavity, waste materials from peritoneal blood vessels diffuse into the dialysis fluid, which is then drained out.
Q.29 What is Haemodialysis?
Answer:
In haemodialysis, patient‘s blood is pumped through an apparatus called dialyzer. It contains long tubing which act as semipermeable membrane. Blood flows through the tubes while the dialysis fluid flows around the tubes. Extra water and wastes move from blood into dialysis fluid. The cleaned blood is returned back to the body.
Q.30 What is glomerulus filtrate?
Answer:
In the glomerulus due to high pressure of blood most of the water, salts, glucose and urea of the blood is forced out of glomerular capillaries. This material passes into the Bowman‘s capsule and is called glomerular filtrate.
Q.31 What are papillary ducts?
Answer:
Many collecting ducts join together to form several hundred papillary ducts which drain into renal pelvis.
Q.32 What are ureters?
Answer:
Kidneys filter blood to produce urine and the ureters carry urine from kidneys to urinary bladder.
Q.33 What is urethra?
Answer:
Urethra is the tube that carries urine from urinary bladder to the outside of body.
Q.34 What is urinary bladder?
Answer:
Bladder is an organ of urinary system which temporarily stores urine until it is released from body.
Q.35 What is urinary system?
Answer:
Excretory system of human is also called the urinary system. It is composed of:
i. Pair of kidneys
ii. Pair of ureters
iii. Urinary bladder and urethra
Q.36 Why transpiration does not take place at night?
Answer:
At night, transpiration usually does not occur because most plants have their stomata closed.
Q.37 What do you mean by kidney stone?
Answer:
When urine becomes concentrated, crystals of many salts e.g. calcium oxalate, calcium and ammonium phosphate, uric acid etc are formed in it. Such large crystals cannot pass in urine and form hard deposits called kidney stones. Most stones start in kidneys, some may travel to ureter or urinary bladder.
Q.38 What is guttation? How does it differ from dew?
Answer:
Guttation
(a) Definition
The appearance of drops of water on the tips or edges of leaves is called guttation. Guttation is not to be confused with dew, which condenses from the atmosphere on to the plant surface.
(b) Explanation
Some plants such as grasses and strawberry force this water through special pores, present at leaf tips or edges, and form drops.
