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Which of the following parts of a plant take part in sexual reproduction? (i) Flower (ii) Seed (iii) Fruit (iv) Branch Choose the correct answer from below. (a) (i) and (ii) (b) (i), (ii) and (iii) (c) (iii) and (iv) (d) (ii), (iii) and (iv)

b) (i), (ii) and (iii) Explanation Flowers take part in sexual reproduction in plants. Seed forms as a result of... View Article

While learning to ride a bicycle Boojho lost his balance and fell. He got bruises on his knees and it started bleeding. However, the bleeding stopped after some time. (a) Why did the bleeding stop? (b) What would be the colour of the wounded area and why? (c) Which type of blood cells is responsible for clotting of blood?

a) Bleeding stopped due to formation of blood clots. b) Dark red due to clotting of blood. c) Platelets are... View Article

Fill in the blanks of the following paragraph using just two words – arteries and veins. _(a)_ carry oxygen-rich blood from the heart to all parts of the body and _ (b)_ carry carbon dioxide-rich blood from all parts of the body back to the heart. _ (c)_ have thin walls and (d)_ have thick elastic walls. Blood flows at high pressure in _ (e). Valves are present in (f) _ which allow blood to flow only towards the heart. (g)_ divide into smaller vessels. These vessels further divide into extremely thin tubes called capillaries. The capillaries join up to form (h)___.

Arteries and Veins are two different types of blood vessels in the circulatory system and are mainly involved in circulating... View Article

Read the following terms given below. (Root hairs xylem urethra arteries kidneys veins atria capillaries heart ureter phloem urinary bladder) Group the terms on the basis of the categories given below. (a) The circulatory system of animals. (b) Excretory system in human. (c) Transport of substances in plants.

The terms on the basis of the categories are: a) Arteries, atria, capillaries, veins, heart are the circulatory systems of... View Article

Paheli noticed water being pulled up by a motor-pump to an overhead tank of a five-storeyed building. She wondered how water moves up to great heights in the tall trees standing next to the building. Can you tell why?

Roots absorb minerals and water from the soil constantly. The suction force is created by evaporation of water from leaves.... View Article

Name the process and the organ which helps in removing the following wastes from the body. (a) Carbon dioxide (b) Undigested food (c) Urine (d) Sweat

Waste Process Organ Carbon dioxide Exhalation Lungs Undigested food Egestion Anus and large intestine Urine Excretion Kidney Sweat Sweating Sweat... View Article

Boojho’s uncle was hospitalised and put on dialysis after a severe infection in both of his kidneys. (a) What is dialysis? (b) When does it become necessary to take such a treatment?

a) The periodical filtering of blood through artificial kidney is termed as ‘Dialysis’. A kidney can filter 100-150 quarts of... View Article

(a) Name the only artery that carries carbon dioxide-rich blood. (b) Why is it called an artery if it does not carry oxygen-rich blood?

(a) The pulmonary artery is the only artery that carries carbon dioxide-rich blood. A pulmonary artery is a set of... View Article

Paheli uprooted a rose plant from the soil. Most of the root tips, with root hairs, got left behind in the soil. She planted it in a pot with new soil and watered it regularly. Will the plant grow or die? Give a reason for your answer.

The possible situations could be a) The plant will die because without the root hairs, the root will not able... View Article

Arrange the following statements in the correct order in which they occur during the formation and removal of urine in human beings. (a) Ureters carry urine to the urinary bladder. (b) Wastes dissolved in water is filtered out as urine in the kidneys. (c) Urine stored in the urinary bladder is passed out through the urinary opening at the end of the urethra. (d) Blood containing useful and harmful substances reaches the kidneys for filtration. (e) Useful substances are absorbed back into the blood.

The arranged statements are: a) Blood containing useful and harmful substances reaches the kidneys for filtration. b) Useful substances are... View Article

Name the organ which is located in the chest cavity with its lower tip slightly tilted towards the left.

Heart Explanation The heart is a blood-pumping organ of the human circulatory system.The human heart is one of the most... View Article

What is the special feature present in a human heart which does not allow mixing of blood when oxygen-rich and carbon dioxide-rich blood reach the heart?

A septum is a diving wall which is present between the the left side and the right side of the... View Article

Veins have valves which allow blood to flow only in one direction. Arteries do not have valves. Yet the blood flows in one direction only. Can you explain why?

The artery have thick elastic walls and arteries receives blood in high pressure directly from the left ventricle. Because of... View Article

Aquatic animals like fish excrete their wastes in gaseous form as (a) Oxygen (b) Hydrogen (c) Ammonia (d) Nitrogen

c) Ammonia Explanation Aquatic animals perform the procedure of ‘Excretion’ depending on the availability and unavailability of water. They excrete... View Article

In a tall tree, which force is responsible for pulling water and minerals from the soil? (a) Gravitational force (b) Transportation force (c) Suction force (d) Conduction force

c) Suction force Explanation Roots absorb minerals and water from the soil constantly. The suction force is created by evaporation... View Article

In which of the following parts of the human body are sweat glands absent? (a) Scalp (b) Armpits (c) Lips (d) Palms

c) Lips Explanation Sweat glands are present in scalp, armpits, and palms but not in lips. So, lips do not... View Article

The absorption of nutrients and exchange of respiratory gases between blood and tissues takes place in – (a) veins (b) arteries (c) heart (d) capillaries

d) Capillaries Explanation Exchange of gases, nutrients, and waste between blood and tissue occurs in the capillaries. Capillaries are tiny... View Article

They are pipe-like, consisting of a group of specialized cells. They transport substances and form two-way traffic in plants. Which of the following terms qualify for the features mentioned above? (a) Xylem tissue (b) Vascular tissue (c) Root hairs (d) Phloem tissue

d) Phloem tissue Explanation Phloem is also important as the xylem tissues for the vascular system of plants. The main activity... View Article

The muscular tube through which stored urine is passed out of the body is called – (a) kidney (b) ureter (c) urethra (d) urinary bladder

C) Urethra Explanation A hollow tube is located between ‘Urinary Meatus’ and ‘Urinary Bladder’ is termed as Urethra. A tube... View Article

A food stall owner was preparing dough for making bhaturas. He added a pinch of yeast and sugar to the dough and left it in a warm place. After few hours, the dough had risen. There was a sour smell too. (a) Why did the dough rise? (b) Why did the dough smell sour? (c) Why was sugar added to the dough? (d) What would have happened if the dough was kept in the refrigerator, soon after it was prepared?

a) Yeast are the single cell organisms which perform anaerobic respiration. The dough rose because of the release of carbon... View Article

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