The tallest living man is Sultan Kösen of Turkey, at 251 cm (8 ft 3 in).

Winnowing is an agricultural method developed by ancient cultures for separating grain from chaff. It is also used to remove hay and chaff or other pests from stored grain.

Every time you blink, your eyelids spread a cocktail of oils and mucous secretions across the surface of the eye to keep your globes from drying out. Blinking also keeps eyes safe from potentially damaging stimuli, such as bright lights and foreign bodies like dust.

Antibiotics are only needed for treating certain infections caused by bacteria. We rely on antibiotics to treat serious, life-threatening conditions such as pneumonia and sepsis, the body's extreme response to an infection. Effective antibiotics are also needed for people who are at high risk for developing infections. Antibiotics are prescribed to treat bacterial infections, which commonly include strep throat, urinary tract infections, and certain types of pneumonia. ... Some research has found that antibiotics may also weaken the immune system's ability to fight off infection, whether it's bacterial or not.

Tears are mostly water and a little bit of salt, but they also have some oil, mucus and chemicals called enzymes that kill germs.

Plants produce two gaseous waste products i.e. oxygen during photosynthesis and carbon dioxide during respiration.

The internal organs, protected by the skin, muscles, and bones, have even fewer nerve endings than the muscles. Conversely, solid organs, such as the lungs, liver, and spleen, have fewer free endings and are not highly sensitive to pain. Hence, they can deteriorate without the individual's becoming very aware of it.

Kharif Crops

1. The term ‘Kharif’ comes from Arabic language means autumn
2. The crops which are grown in the rainy season are called Kharif crops
3. Seeds are sown in the month of June/July
4. Harvested during the months of October/November
5. These crops are also known as monsoon crops
6. These crops depends on the quantity of rain water as well its timing
7. These crops can grow in hot and wet conditions
8. Examples of Kharif crops are paddy, maize, soyabean, groundnut, cotton etc.,

Rabi Crops

1. The term ‘Rabi’ comes from Arabic language means spring.
2. The crops which are grown in the winter season are called Rabi crops
3. Seeds are sown in the month of November/December
4. Harvested during the months of March/April
5. These crops are also known as winter crops
6. These crops mainly depends on the water that has percolated in the ground during rainy season
7. These crops grow in cold and dry conditions
8. Examples of Rabi crops are wheat, gram, pea, mustard, linseed etc.,

Combustible substances are also known as inflammable.
Combustible substances: Those substances which undergo combustion or burn are called combustible substances.

For example: Paper, cloth, cooking gas (LPG), CNG, Kerosene oil, wood, charcoal, etc.

• The major climate change due to global warming is definitely a significant increase in global temperature.
• Global warming is a threat to animals and plants. It is disturbing the entire ecological balance of the environment. Melting of polar ice caps and glaciers is increasing the rise in the water levels (sea and ocean) all around the globe. Furthermore, freshwater resources are reducing day by day.

Before sowing, soil should be prepared well by ploughing and irrigation. Irrigation helps in moisturing and loosing the soil. It is necessary to loosen soil because only loose soil allows the roots to penetrate freely deeper into soil.

Water is an important natural resource on our earth. Excessive irrigation lead to many problems like decrease in level of ground water, increase chance of drought, water logging can harm land as well as plants.

Farmers collect and use wastes from animal, human and vegetable sources(manures) for improving crop productivity.

Petrochemicals are those substances which are obtained from petroleum and natural gas. These are used in the manufacture of detergents, fibres, polythene, etc.

An enormous variety of organisms exist, including some which can survive and even develop in the body of the host. If the organism can cause infectious diseases, it is an infectious agent. In this manual infectious agents which cause infection and illness are called pathogens.

The bodies of all living organisms are made up of microscopic units called units. The temporary mounts of onion peels have different sized but similar small structures. There are some organisms that are single celled but can live their own. Such organisms are called unicellular organisms. Example – Amoeba, Chlamydomonas, Paramoecium and bacteria. The organisms in which the body is made up of many organisms are called multicellular organisms. Many cells group together in a single body and assume different functions in it to form various body parts in multicellular organisms such as some fungi, plants and animals.

Formation of petroleum

• This fossil fuel is formulated from the dead sea plants and animals.
• As they died their bodies settle down in the bottom surface of the sea.
• With the passage of time they get compressed as more layers of sand and clay deposited over them.
• Under high temperature and pressure along with the absence of air these dead plants slowly got converted to petroleum and natural gas.

Petroleum consists of several constituents as mentioned above. They need to be separated from the crude oil by a series of processes. This process of separation of the wide variety of constituents of petroleum is called Refining of Petroleum carried out in petroleum refinery

Some microorganisms get settled on the food stuff. They release the toxic substances in the food stuff. This makes the food contaminated and unfit for use. This is called food poisoning. If anyone consumes this food, it can produce fatal results. Serious illness is caused and patient get frequent vomiting and loose motion.

This physical condition can lead even to death. So it is very important that we preserve food to prevent it from being spoilt.

Plastics release toxic : True

In chemical laboratory, many chemicals are stored in plastic bottles because plastics are non reactive, inexpensive and can be re-used. While metal containers can react with chemicals.

Plastic is a unique material which becomes soft on heating and hard on cooling. It melts at moderately high temperature without decomposing.

As liquids have a tendency to take the shape of container therefore, when molten plastic is poured in different vessels, it takes the shape of vessel on cooling. Thus a plastic can be moulded into different shape and sizes.