As we know that normal body temperature is 37⁰C.

Mature ovary forms the fruit.

No. Our body does not get enough oxygen in such cases.

Earthworms are called a farmer's friend because earthworms till the land by moving in soil when the land is watered.

(i) Lightning conductor should be installed on large buildings. When lightning strikes, it provides a path to the charge to pass through it.
(ii) We should be stand under a tree because lightning can set the tree on fire.
(iii) We should confine ourselves indoors.

The water found deep below the earth between particles of soil and the gaps between the rocks is called underground water. It gets filtered through many layers of sand, rock and soil. It contains dissolved salts but is free from suspended impurities. It can be obtained from wells, tube wells and hand pumps.

When a new substance is formed in a chemical reaction, heat, light is produced or used up. The chemical properties of the reaction mixture becomes different from the reactions.

The silk yarn is obtained form the cocoon of the silk moth. There is a variety of silk moths which look very different from one another and the silk yarn they yield is different in texture like coarse, smooth and shiny etc. Thus tassar silk, mooga silk and kosa silk are obtained from cocoons spun by different types of moths. The common silk moth is the mulberry silk moth. The cocoon of this moth yield soft, lustrous and elastic silk fibre.

Phenolphthalein indicator is generally used in neutralization reaction.

When the current is passed through the wire wound on the nail, it behave as electromagnet. Due to this reason, the nails attract the pins.

Window should preferably towards the sea beach so that the sea breeze coming from sea keeps the house cool during the day time.

Fungus, moss and fern reproduce by the common method of spore formation which is a type of asexual reproduction.

The effluent treatment plants filter out undissolved materials form water.

There are two types of lenses. 
The lens which is thinner in the middle than at the edges is called a concave lens while the lens which is thicker in the middle than at the edges is called a convex lens

When the object is at rest, then the distance-time graph of an object is a horizontal line parallel to the axis of time.

Grass ⟶ Insects ⟶ Frog ⟶ Eagle

Pulmonary veins carry oxygenated blood from lungs to heart.

Cactus, the part where photosynthesis occurs are stem and branches which are green.

The digestive juices from liver and pancreas is poured into small intestine which helps in complete digestion and absorption of food.

In North-Eastern regions, wet climate is found because it receives rain for major part of the year.

The wool obtained after shearing contains a substance called yalk which consists of complex chemical lanolin. In addition to it, the same wool contains suint, which is dried perspiration of sheep. These are removed by washing with soap-alkali preparation or some suitable detergent in tanks. This process is called scouring.

(i) An acid is the compound formed by the reaction of acidic oxide with water. e.g., HCl, whereas alkali is the hydroxide of metals dissolved in water. e.g., KOH.
(ii) A base is a substance containing hydroxide group. e.g., NH₄OH, whereas alkali is the base which is soluble in water. e.g.,NaOH.
(iii) Organic acid is a weak acid derived from plants or animals. e.g., acetic acid. Mineral acid is a strong acid derived from earth minerals. e.g., HCl.

The number of problems that can be faced due to shortage of water are as follows
(i) Less amount of pure drinking water will be available.
(ii) Lack of equal distribution of water.
(iii) Drought.

An electromagnet can be switched OFF or switched ON as desired and this is not possible in the permanent magnets. That is why the electromagnets are better than the permanent magnets.

(a) The given figure is of Bryophyllum leaf. It is also called as sprout leaf plant.
(b) It shows vegetative reproduction by leaves.
(c) The leaves of Bryophyllum develops some buds in its margin or edges which grow into new plants when buried in the soil.

In places of hot climate, it is advised that the outer walls of houses be painted white because white colour does not absorb any heat radiation from ·the sun which keep inside cool even if there is hot climate outside the house.

The correct sequence of wastewater treatment in treatment plant is
(c) Large objects like plastic bags are removed by passing wastewater through bar screens.
(e) Wastewater enters a grit and sand removal tank.
(d) Sand, grit and pebbles are made to settle by decreasing the speed of incoming wastewater.
(b) Water is made to settle in a large tank with a slope in the middle.
(a) Sludge is scraped out and skimmer removes the floating grease.

These mirrors can be differentiated by bringing our face close to each mirror turn by turn. Since, a plane mirror will produce an image of the same size as our face while a concave mirror will produce a magnified image and our face will look much bigger and on other sides, a convex mirror will produce a diminished image and our face will look much smaller like a small child.

Given, the average age of children 12 years and 3 months
1 year = 365 days = 365 \(\times\) 24 h                              [ 1 day = 24 h ]
= 365 \(\times\) 24 \(\times\) 3600 s                                              [ 1 h = 36000 s]
12 years = 31536000 s \(\times\)12 = 378432000 s
3 months = 30 \(\times\) 3 days = 30 \(\times\) 3 \(\times\) 24 h = 30 \(\times\) 3 \(\times\) 24 \(\times\) 3600s = 7776000s
So, total age in second = 378432000 + 7776000 = 386208000s

(a) (i) Folding of paper
(ii) Melting of ice
(b) (i) Tearing of paper
(ii) Breaking of glass
(c) (i) Reaction between vinegar and baking soda.
(ii) Burning of a matchstick.

The set of wind blowing from the cold polar regions towards 60° Nand 60° S latitudes are called polar winds.

The human heart is divided into four chambers, i.e. upper two atrium and lower two ventricles. The functions of these chambers can be tabulated as follows

The animals in forests are of various types. These could be herbivores, carnivores, microorganisms, etc. These play an important role in maintaining the food chains.
(i) Microorganisms convert the dead plants and animals into humus. This humus helps in returning the nutrients back to the soil. These are absorbed by plants.
(ii) The animals also help in dispersing the seeds of certain plants.
(iii) The decaying animal dung provides nutrients.
All these activities of animals dwelling in the forest help it to grow and regenerate.

Yes, plants having deep red, violet or brown coloured leaves can also carry out photosynthesis because they contain chlorophyll. But their green o colour of chlorophyll is masked by the large amount of all other coloured pigments.

The various components of food and their simpler forms are

Labelled sketch of the cross-section of soil is

The factors that affect the climate of a place are
(i) Temperature zone or latitude, i.e. amount of sunshine it receives or distance from equator.
(ii) Distance from sea.
(iii) Altitude or height above the sea level.
(iv) Humidity or the presence of moisture in air.
(v) Amount of precipitation received or rainfall.

A cockroach has small opening on the side of its body. These openings are called spiracles. Insects have a network or air tubes called tracheae for gas exchange, oxygen rich air rushes through spiracles into the tracheal tubes, diffuses into the body tissues and reaches every cell of the body. Similarly carbon dioxide from the cells goes into the tracheal tubes and moves out through spiracles. These air tubes or tracheae are found only in insects

(i) This is a method known as asexual reproduction in which new plants may appear from older parts like stem, root, leaf etc. without seed formation. This is called as vegetative propagation.
(ii) Ginger, garlic, bryophyllum, banana etc.
(iii) (a) It takes less time to grow and bear flowers and fruits.
(b) New plants are exact copy of the parent plant.
(iv) Helping attitude towards her mother, curiosity to know scientific fact.

(i) Left overfood contains lot of oil and fat, it should not be thrown down the drain. They choke the pipe when they become harden. These waste when thrown in open drains block the oil pores thereby decreasing its effectiveness to filter water. Such wastes should be thrown in dustbin only.
(ii) Solid wastes such as used tea leaves, plastic bags, soft toys, cotton and sanitary towels should not be thrown in drains. Such wastes block the drain. They reduce free flow of oxygen and thus slow down the process of degradation.
(iii) Chemical products like medicines, motor oil, paint, machine oil and insecticide should also be not thrown down the drain. These substances kill water purifying organisms and hamper degradation.

When current is passed through a coil of wire then the coil behaves like a magnet. One end of coil acts as north pole and other end acts as south pole When the electric current is swithed off, the coil generally loses its magnetism. Such coils are called electromagnets. The electromagnets are very strong and their power can be increased so they are very important.
Two important applications (uses)of electromagnets are:
(i)They are used in electric bells, telegraphs telephones and speakers etc 
(ii) They are used in cranes to lift heavy loads of scrap iron or iron sheets

(i) Actually, millions of people in our country do not get enough water. Especially during summer, in many areas there is an acute shortage of water, taps running dry, long queues for water and even fight for demand of water in a common sight.
(ii) Causes: Due to less amount of rainfall in some areas, not only water bodies like ponds, rivers become dry also due to excess extraction of ground water, water table goes down.
Remedies: Public and government both should be concern and show awareness towards this crisis. By drip irrigation system and water harvesting technique, we cannot only save water from wastage but also recharge ground water.
(iii) In these areas of hot dry and arid climate the studies of children are badly affected.

Cyclones can be very destructive as they travel over seas at 15-30 km/h and the strong winds push water towards the shore even when the storm is hundreds of kilometres away. This is actually the first indication of an approaching cyclone. The central low pressure area lifts the water surface in the centre to a height of 3 - 12 metres and it appears like a water wall moving towards the shore. As a result seawater enters and floods the low lying coastal areas causing loss of life and property. This reduces the fertility of the soils also. Since cyclones are accompanied by heavy rainfall, it further worsens the flood situation. In addition, the communication system, livestock, trees, buildings, bridges and many other man-made structures are also damaged by high speed wind.

A-Septum between right and left side of heart. It prevents mixing of oxygenated and deoxygenated blood.
B-Left ventricle,which pumps oxygenated blood to body parts.
C-Aorta is the main artery emerging from left ventricle. It gives rise to other arteries which carry blood to different body parts.
D-Left auricles, which receives oxygenated blood from lungs and pushes it into left ventricle.
E-Pulmonary vein brings oxygenated blood from lungs to left auricle.

The forest acts as a natural absorber of rain water and allows it to seep. It helps to maintain the water table throughout the year. Forests not only helps in controlling floods but also help to maintain the flow of water in the streams so that we get a steady supply of water. On the other hand, if trees are not present rain hits the ground directly and may flood the area around it. Heavy rain may also damage the soil. Roots of trees normally bind the soil together, but in their absence the soil is washed away or eroded.

 

(i) Time in minutes on x-axis and speed in m/min on y-axis.
(ii) On x-axis, 10 divisions = 1 min and on y-axis 10 divisions = 25 m/min
(iii) At 3.30 minutes, the speed of car is 30 m/min.
(iv) Distance at 4 min = Speed x Time = 52.5 x 4 = 210.0 m
(v) After 6.30 minutes the car has assumed constant speed.

(a) When the object is far away the image is real, inverted and smaller in size.

(b) When the object is between F and radius lens, the image is real, inverted but bigger in size.

(c) When the object is near to the lens. The image is real, inverted and much bigger (magnified).

The particles of water become more lighter and rise up in the middle. Due to this, the cold particles of water which are heavier come down along the sides of the vessel. So, the convection currents of heat are setup and water becomes hot. The moment, when the heat is applied at the top, then the water present in the upper portion becomes hot and these hot water molecules get fixed over the surface. Since, water is a bad conductor of heat, due to which water present at the lower end (or bottom) of the vessel remains.

In first saree, one thread which burnt with a smell of burning hair is from pure silk, silk and hair are protein fibres. So, on burning these threads, a smell of burning hair comes out. In second saree, second thread which burnt with the smell of burning cotton and paper because cotton and paper both are carbohydrates and on burning they give similar smell.

(a) Chemical reaction between copper sulphate solution and iron metal. In this reaction, blue colour of copper sulphate solution changes to light green colour due to the formation of iron sulphate.
Copper sulphate + Iron \(\longrightarrow\) Iron sulphate + Copper
(Blue)                    (Grey)       (Light green)     (Brown)
(b) When baking soda and vinegar are mixed together then a chemical change takes place and bubbles of carbon dioxide gas are formed along with some other substances.
Baking soda              +                Vinegar          \(\longrightarrow\)     Sodium acetate + Carbon dioxide + Water
(Sodium hydrogen carbonate)   (Acetic acid)
(c) Explosion of a firework produces heat, light, sound and unpleasant gases. Explosion of a firework is a chemical change.

(a) The various important component of soil are air, water, rock particles, minerals,
humus and living organisms like bacteria fungi, worms (earthworm), rodents, insects (ant and beetle), etc.
(b) The increasing order of rock particles are
Clay \(\rightarrow\)  Silt \(\rightarrow\) Sand \(\rightarrow\) Gravel
(c) The figure shows waste rnaterial like polythene bags, plastics, glass and metal objects are dumped which causes soil pollution.

(a) Hiccup is a choking sensation that produces a characteristic gulping sound repeatedly. It is called 'hicki' in our local language.
(b) Sometimes, when we eat too fast in a hurry or talk too much or laugh while eating, then a little of windpipe remains open due to which food particles may enter the windpipe. It may result in a choking sensation called hiccups.
(c) He is sincere and curious to know about the things at an early age.

The process by which green plants can prepare their own food is called photosynthesis. Green plants possess chlorophyll in their leaf and utilises carbon dioxide (from air) water, minerals (from soil, through root) as raw material and sunlight as source of energy and convert light energy into chemical energy. The food thus synthesied is in the form of starch (carbohydrate). The overall reaction for photosynthesis can be given as follows:

(a) Rohan observed a camel in the desert of Rajasthan.
(b) The hump stores fat which provides camel with food in times of food shortage.
(c) The feets of camel has large soles which help it to walk on soft sond.
(d) Camel can drink a very large quantity of water at a time which is stored in its stomach. It sweats very little which helps it to conserve water. Also it excretes very little water in the form of urine.
(e) Rohan is observant, curious and adventurer. He asks intelligent questions.