Draw a diagram of the human excretory system and label the various parts.
The excretory system of human beings consists of the following organs that are: two kidneys, two ureters, a bladder and a urethra. The kidneys are bean-shaped organs which are present towards the back of our body just above the waist. The decomposition of unused food proteins in the liver produces urea as waste. This function of kidneys is to filter the blood to remove urea or we can say the excretion of nitrogenous waste from the body occurs by the kidneys.
Each kidney contains numerous tiny filters called ‘nephrons’. When the blood containing urea and other waste salts they passes through the nephrons in the kidneys then these nephrons filters the blood and remove urea and other unwanted inorganic salts from it. The liquid left in the kidneys is yellowish liquid called ‘urine’ which contains urea, other waste salts and excess water which is formed in kidneys, goes into the bladder through the tubes called ureters. Urine is stored in the bladder and is also called ‘urinary bladder’. The urine collected in bladder is passed out from the body at regular intervals through the opening at the end of a tube which is called urethra. Urine is yellowish liquid which consists of 2.5 percent urea, 2.5 percent other waste inorganic salts and 95% of water. An adult human being normally passes out 1 to 1.8 litres of urine per day (24 hours).
Human excretory system
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Classify the changes involved in the following processes as physical or chemical changes:
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(d) Melting of wax
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Given below is a crossword puzzle based on this lesson. Use hints to fill in the blank spaces with letters that complete the words.
Down Across
(D) 1 : Thorough washing (A) 1 : Keeps warm
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Sketch the cross section of soil and label the various layers.
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An iron ball at 40°C is dropped in a mug containing water at 40°C. The heat will
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(c) flow from water to iron ball.
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Write one similarity and one difference between the nutrition in amoeba and human beings.
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Match the items in Column I with those in Column II:
Column I Column II
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One litre of water at 30°C is mixed with one litre of water at 50°C. The temperature of the mixture will be
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(a) 80°C (b) more than 50°C but less than 80°C
(c) 20°C (d) between 30°C and 50°C - Q:-
Tick the correct answer:
(a) The reproductive part of a plant is the
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