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Paheli accidentally placed her hand over a flame and immediately pulled it back. She felt the sensation of heat and reacted due to the action of (a) blood cells (b) skin surface (c) nerve cells (d) nucleus of cells

(c) nerve cells Paheli accidentally placed her hand over a flame and immediately pulled it back. She felt the sensation of heat and reacted due... View Article

Which is the correct sequence of parts in the human alimentary canal? (a) Mouth → stomach → small intestine → oesophagus → large intestine (b) Mouth →oesophagus → stomach → large intestine → small intestine (c) Mouth → stomach → oesophagus → small intestine → large intestine (d) Mouth → oesophagus → stomach → small intestine → large intestine

d) Mouth → Oesophagus → Stomach → Small intestine → Large intestine The different organs of the alimentary canal can be... View Article

Unscramble the jumbled words underlined in the following statements. (a) Cells of our body produce santiidobe to fight pathogens. (b) curbossulite is an air-borne disease caused by a bacterium. (c) Xanrhat is a dangerous bacterial disease. (d) Yeasts are used in the wine industry because of their property of meronettinaf.

(a) Cells of our body produce antibodies to fight pathogens. An antibody is a protein produced by the body's immune system when it detects... View Article

Find out the correct sentence about manure (i) Manure contains large quantities of organic matter and small quantities of nutrients. (ii) It increases the water holding capacity of sandy soil. (iii) It helps in draining out of excess of water from clayey soil. (iv) Its excessive use pollutes environment because it is made of animal excretory waste. (a) (i) and (iii) (b) (i) and (ii) (c) (ii) and (iii) (d) (iii) and (iv)

b) (i) and (ii) Manure is an organic matter derived from the solid animal wastes, used to improve the soil quality and increase the yield of... View Article

Some of the following statements are incorrect. Find the incorrect statements and correct them. (a) The property of metals by virtue of which they can be drawn into wires is called ductility. (b) Metals are good conductor of electricity but poor conductor of heat. (c) Articles made of metals produce ringing sound when struck hard. (d) Oxides of non-metals and metals are acidic in nature. (e) A less reactive metal replaces a more reactive metal from its salt solution in water.

Statements 2, 4 and 5 are not correct. 2. Metals are good conductors of electricity and also good conductors of heat. Metals are an excellent... View Article

Vectors can be defined as (a) animals carrying the infecting agents from sick person to another healthy person (b) microorganisms which cause many diseases (c) infected person (d) diseased plants

a)Animals that carry the infecting agents from an infected individual to another healthy individual. Vector Borne diseases are the illness... View Article

Plasmolysis in a plant cell is defined as (a) break down (lysis ) of plasma membrane in hypotonic medium (b) shrinkage of cytoplasm in hypertonic medium (c) shrinkage of nucleoplasm (d) none of them

B) Shrinkage of cytoplasm in hypertonic medium When a plant cell is kept in a hypertonic medium, the water inside the cell moves outside due to... View Article

Boojho has learnt that non-metals on beating with a hammer are generally broken into pieces. Which of the following is a nonmetal? (a) Iron nail (b) Aluminium wire (c) Copperplate (d) Piece of coal

(d) Piece of coal In the given options iron, aluminium and copper, all are metals, but only carbon is a non-metal which is breakable with a... View Article

Read the different combinations of terms given below: (a) cell wall, cell membrane, nucleus, plastid (b) cell wall, nucleus, ribosome, chromosome (c) the cell membrane, mitochondria, ribosome, chromosome (d) the cell membrane, ribosome, mitochondria, chloroplast. The correct combination of terms with reference to an animal cell is _____.

c) Cell membrane, Ribosome, Mitochondria, Chromosome The correct combination of terms with reference to an animal cell is cell membrane,... View Article

On converting 25°C, 38°C and 66°C to kelvin scale, the correct sequence of temperature will be (a) 298 K, 311 K and 339 K (b) 298 K, 300 K and 338 K (c) 273 K, 278 K and 543 K (d) 298 K, 310 K and 338 K

(a) Therefore, the correct sequence of temperature will be 298 K, 311 K and 339 K. On converting 25 °C, 38 °C and 66 °C, to kelvin... View Article

Which of the following is not true for fertilisers? (a) They increase the yield. (b) Their excessive use disturbs the balance of nutrients in the soil. (c) They are generally used in small quantity. (d) They are environment-friendly.

They are environment friendly. Fertilizers are chemical substances supplied to the crops to increase their productivity. These are used by the... View Article

A pond contains clean water. Which of the following activities will produce the least pollution of water? (a) washing clothes in the pond (b) animals bathing in the pond (c) washing motor vehicles in the pond (d) swimming in the pond.

d) Swimming in the pond Swimming in the pond will produce the least pollution of water because no harmful pollutants or any chemicals would be... View Article

If salivary amylase is lacking in the saliva, which of the following events in the mouth cavity will be affected? (a) Proteins breaking down into amino acids (b) Starch breaking down into sugars (c) Fats breaking down into fatty acids and glycerol (d) Absorption of vitamins

b) Starch breaking down into sugars Amylase is the enzyme that catalyses the hydrolysis of starch into simple sugars. So if salivary amylase is... View Article

Find out the false statement (a) Aves are warm-blooded, egg laying and have a four-chambered heart (b) Aves have feather-covered body, forelimbs are modified into wings and breathe through lungs (c) Most of the mammals are viviparous (d) Fishes, amphibians and reptiles are oviparous

d) Fishes, amphibians and reptiles are oviparous. There are a few fishes, amphibians and reptiles which are viviparous. Sharks, stingrays,... View Article

Which of the following statements is correct about receptors? (a) Gustatory receptors detect taste while olfactory receptors detect smell (b) Both gustatory and olfactory receptors detect smell (c) Auditory receptors detect smell and olfactory receptors detect taste (d) Olfactory receptors detect taste and gustatory receptors smell

a) Gustatory receptors detect taste while olfactory receptors detect smell Gustatory receptors are present in the taste buds present over the... View Article

A few drops of iodine solution were added to rice water. The solution turned blue-black in colour. This indicates that rice water contains (a) complex proteins (b) simple proteins (c) fats (d) starch

d) Starch A solution of iodine and potassium is added to a starch-containing substance instead of molecular iodine because molecular iodine... View Article

In which of the following vertebrate group/groups, the heart does not pump oxygenated blood to different parts of the body? (a) Pisces and amphibians (b) Amphibians and reptiles (c) Amphibians only (d) Pisces only

d) Pisces only In Pisces, the heart does not pump oxygenated blood to different parts of the body. This is because Pisces have a two-chambered... View Article

A person met with an accident in which two long bones of hand were dislocated. Which among the following may be the possible reason? (a) Tendon break (b) Break of skeletal muscle (c) Ligament break (d) Areolar tissue break

(c) Ligament break The two long bones in hand are the radius and the ulna. Annular ligament or orbicular ligament is a strong band of fibres... View Article

What happens when rain falls on soil without vegetational cover? (a) Rainwater percolates in soil efficiently (b) Rainwater causes loss of surface soil c) Rainwater leads to fertility of the soil (d) Rainwater does not cause any change in soil

(b) Rainwater causes loss of surface soil When the soil is without vegetation cover, the rainwater carries away the soil and causes its loss.... View Article

You are aware of Polio Eradication Programme in your city. Children are vaccinated because (a) vaccination kills the polio causing microorganisms (b) prevents the entry of polio causing organism (c) it creates immunity in the body (d) all the above

c) It creates immunity in the body A vaccine is a preparation that improves immunity to a particular disease. It is a biologically... View Article

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