Spore formation is one form of asexual reproduction. Spore formation is the method of developing new individuals by forming reproductive structures called spores.
*A spore is a small spherical or oval structure which protects the future individual in a thick protective covering.
*Spore germinates on a substratum under favourable conditions.
*Some organisms like ferns, some groups of fungi reproduce by spore formation.
e.g.Fungus reproduces by means of spores. Fungus like bread mould produce spores which germinate on moist organic surfaces. The cottony white mass on bread formed by fungus after spore germination is called a mould. Spores can survive in extreme conditions because of the protective hard coat.

On heating the bottom of the flask with a very small gas flame an upward current of colored water will ascend from the place where heat is applied. This colored stream reaches the top and spreads out. After a short time it circulates down the sides of the flask, showing that a convection current has been set up.

Most flies have mouthparts that are best described as two sponge pads and a straw. Their lips have grooved channels that allow liquid to flow in from the two fleshy pads attached to the fly's lower lip (the labella). Since they cannot chew, flies have to dissolve solid food into liquid, or at least into particles measuring 0.45 millimeters or less. To do this, the fly regurgitates saliva from its stomach, which dissolves the food until it is digestible. The house fly then uses its proboscis to suck up the liquefied food.
Though they eat with their mouths, house flies taste with their feet. This is why they are always crawling on your food. Since they also "taste" spoiled meat and feces, the last place you want them crawling is on food you're about to put in your mouth – not to mention flies constantly defecate.

The parts of digestive tract are:

• Mouth and buccal cavity
• Food pipe/Oesophagus
• Stomach
• Small intestine
• Large intestine
• Rectum
• ****

There are some associated glands that secrete enzymes which help in digestion of food. These include:

• Salivary glands
• Liver
• Pancreas

The digestive tract and the associated glands together constitute digestive system.

A cyclone is a huge revolving storm caused by very high speed winds blowing around a central area of very low pressure in the atmosphere. A cyclone revolves due to the force exerted by the rotation of earth. The centre of a y the rotation of earth. The centre of a cyclone is called the ‘eye’ of the cyclone. The eye of cyclone is a region free of clouds and it has only light winds. Around the calm and clear eye of cyclone, there is a cloud region of about 150 kilometres in size. In this region, there are very high speed winds (having speeds of 150 km/h to 250 km/h) which are moving in circles around the eye, and thick thunderclouds which produce heavy rain.

1. The thermometer that measures our body temperature is called a clinical thermometer.

 2. Hold the thermometer in  your hand and examine it carefully.

3. A clinical thermometer consists of a long, narrow, uniform glass tube. It has a bulb at one end. This bulb contains mercury. Outside the bulb, a small shining thread of mercury can be seen.

4.Thermometer should be washed before and after use, preferably with an antiseptic solution.

5. Ensure that before use the mercury level is below 35°C.

6. Read the thermometer keeping the level of mercury along the line of sight.

7.  Handle the thermometer with care. If it hits against some hard object, it can break.

8.  Don’t hold the thermometer by the bulb while reading it.

Humus: The decaying dead matters in soil are called humus. Humus makes the soil fertile and provides nutrients to the plants.
 

Clayey Sol: Particles of clayey soil are very small in size. This makes the particles of clayey soil packed tightly. There is very little space among the particles. Water does not drain quickly through clayey soil because of less space among particles. So, clayey soil is not well aerated and retains more water.

Clayey soil is used in making of toys. Clayey soil is good for growing paddy.

Loamy Soil: Particles of loamy soil are smaller than sand and larger than clay. Loamy soil is the mixture of sandy soil, clayey soil and silt. Silt is the deposit in river beds.

Percolation Rate of Water: Amount of water drained through water in unit time is known as percolation rate of water in soil.

Moisture present in soil: Amount of water present in soil is called moisture present in soil. The amount of moisture present in clayey soil is highest and that in sandy soil is lowest.

Sandy soil: Sandy soil is not fit for any crop as it does not retain water. However, some thorns and bushes do grow on sandy soil. Millets can be grown on sandy soil.

hemoglobin pigment gives blood its red colour

Each of the red blood cells contains hemoglobin. Hemoglobin is an iron rich protein. When hemoglobin binds with oxygen, the interaction between them gives our blood its red color.

Excretion of wastes

The process of removal of the toxic waste products produced due to cellular activities is called excretion.

The parts of the body of organisms involved in the process of excretion are called excretory system.

The human excretory system consists of – kidney, ureter, urinary bladder, urethra.

Various activities always go on inside the body of a living being. These activities are collectively called metabolism. Many harmful substances are created during metabolic activities. These substances can prove lethal if not removed from the body in time. Removal of waste from the body is called excretion.
The human excretory system is composed of a pair of kidneys, two tubes; called ureter and a urinary bladder.

Animal products too are a rich source of nutrients. The food chain is composed of exactly these animals starting with organisms that use the energy of the sun to the apex at which the organisms are predators and rely on producers.

Cell was discovered in the year 1665 by Robert Hooke.

Q : Mention some sources of Natural sources of acid

A n s w e r :
( a ) Citric acid - Lemon .

(b) Oxalic acid - Tomatoes.

(c) Lactic acid - Sour milk or curd.

(d) Tartaric acid - Tamarind.

The process of making of food by green plants in the presence of sunlight and chlorophyll is known as photosynthesis. Photosynthesis is the combination of two words- Photo + Synthesis. ‘Photo’ means light and ‘Synthesis’ means to make.

Process of food making in green plants:

Green plants make their food themselves. Green leaves make food from Carbon dioxide and water in the presence of sunlight and chlorophyll.

Leaves have several tiny pore-like structures on the lower surface. Such a pore is called stomata through which leaves absorb carbon dioxide from air. Water is transported to the leaves through hair like pipelines from the roots. These pipelines are present throughout the plant, i.e. from roots to branches and leaves. These pipe-lines are known as Xylem. Xylem is a type of tissue. Chlorophyll, a green pigment, is found in green leaves. Chlorophyll absorbs sunlight and gives energy. Chloroplast is the site of photosynthesis. Carbohydrate is used as food and oxygen is emitted out to atmosphere. This whole process of making food by plants is called photosynthesis.

The reaction that takes place in the process of photosynthesis can be written as:

<i>6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂</i>

Carbohydrate which is produced in the process of photosynthesis is ultimately converted into starch and stored in leaves. From leaves it is transported to different parts of a plant. Starch is a type of carbohydrate. The oxygen so produced is released into atmosphere through the stomata.

Leaves are known as the kitchen or food factories of the plants because photosynthesis takes place in leaves. Leaves look green because of the presence of chlorophyll.

Besides leaves, photosynthesis also takes place in other green parts of the plant also, such as in green stems. Chlorophyll is necessary for photosynthesis; hence photosynthesis takes place only in green plants.

The leaves of plants that grow in desert areas are modified in spine like structure or scales to reduce the loss of water in the course of transpiration. In such plants photosynthesis takes place in green stems. Stem is modified into thick spongy leaf-like structures in such plants.

Photosynthesis helps to maintain a balance between oxygen and carbon dioxide in the atmosphere as it absorbs carbon dioxide and release oxygen.

Sunlight is necessary for photosynthesis. Thus sun is the ultimate source of energy for all living organism.

Our earth is the unique planet, where photosynthesis takes place. In the absence of photosynthesis life would not be possible on earth.

After fertilisation has taken place in flower, a zygote is formed which divides several times to form an embryo within the ovule. The ovule develops a tough protective coat around itself and is gradually converted into a seed. The ovary grows rapidly and ripens to form a fruit. Meanwhile, the petals, sepals, stamens, style and stigma gets shriveled and fall off.

After fertilisation has taken place in flower, a zygote is formed which divides several times to form an embryo within the ovule. The ovule develops a tough protective coat around itself and is gradually converted into a seed. The ovary grows rapidly and ripens to form a fruit. Meanwhile, the petals, sepals, stamens, style and stigma gets shriveled and fall off.

Clothes are made of cloth. Cloth is also known as fabric. Fabric is made of fiber.

The air in the soil is necessary to have different locations of biological events. Plants absorb air through their roots; that is, they breathe through them, absorb oxygen, and release carbon dioxide. It is the opposite of the photosynthesis process, in which the leaf absorbs carbon dioxide and releases oxygen, which is necessary for plant cells. Underwater plants like rice actually have air pockets at their roots to be able to breathe.

The air in the soil also allows microorganisms that break down organic matter to live and reproduce. This turns the organic waste into smaller particles, which can benefit the growing plant because the organic matter releases nutrients into the soil.

The complete process of making or producing Fabrics from fibres includes:

Extraction of fibres either from the plant or animal source.

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A group of filament or staple fibres extracted are twisted together to form a yarn.

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 These yarn are twisted tightly and allowed to rotate on the different types of by the rollers, weaved and knitted by passing a different number of yarns together to produce Fabrics.

Finally, the fabrics are produced. These fabrics are treated with chemicals in the textile industries to make different types of clothing materials like cotton fabrics, woollen fabrics, silk fabrics, polyester fabrics etc. Later these fabrics are processed for bleaching to give a smooth, shiny look, colour dying to add colours to the fabric materials and screen printings to design the fabrics.

 When converting from smaller(m/s) to larger(km/hr),use the larger ratio i.e. 18/5.
50 m/sec × 18/5  = (50 ×18)/5 = 900/5 = 180 km /hr