Explanation

• Gases have neither a fixed volume nor a fixed shape.
• As their particles are widely spaced and free to move in any direction, expanding to fill their container.

Explanation

• Fuel is the major source of release of direct pollutants in air pollution.
• Primarily due to the combustion of fossil fuels, which releases harmful pollutants into the atmosphere.

Fuel combustion releases pollutants such as:

• Particulate matter (PM)
• Carbon monoxide (CO)
• Nitrogen oxides (NOx)
• Sulfur dioxide (SO2)Volatile 
• organic compounds (VOCs)

These pollutants can come from various sources, including:

• Transportation (vehicles, airplanes)
• Industrial processes (power plants, refineries)
• Residential and commercial heating and cooking

Explanation

Seed germination requires three essential conditions:

1. Water (H2O): Seeds need water to break dormancy and initiate germination.
2. Oxygen (O2): Seeds require oxygen for cellular respiration and energy production.
3. Proper Temperature: Seeds germinate within a specific temperature range (usually between 16°C to 24°C), which activates enzymes and metabolic processes.

Explanation

• Grease is a lubricant that can be used to reduce friction between moving parts of machines.
• It helps to reduce wear and tear, prevent overheating, and allow parts to move smoothly.

Explanation

In a solid, the particles are arranged in a regular and closely packed manner, with a fixed position and shape.

Explanation

• Cholera, diarrhea, and typhoid diseases are waterborne diseases caused by microbial pollutants.
• Such as bacteria (Vibrio cholerae, Salmonella Typhi), viruses, and protozoa (Entamoeba histolytica) that contaminate water sources.

Explanation

Flowering plants are classified into two main groups:

1. Monocotyledons (Monocots) have one cotyledon. Examples: maize, rice, wheat, grasses.
2. Dicotyledons (Dicots) have two cotyledon. Examples: mango, lemon, gram, beans or pea, sunflowers.

Explanation

• In a gas, the particles have no regular pattern and have large empty spaces between them.
• The particles are widely spaced and are free to move in any direction, with no fixed position or arrangement.

Explanation

• Coleoptile is a protective sheath that covers the emerging plumule (shoot) in grasses, including maize (Zea mays).
• It is a characteristic feature of monocotyledonous plants, particularly in the family Poaceae (grass family).

Explanation

• Birds are a group of animals that lay eggs, are warm-blooded, have either a beak or bill, have feathers on their body, and have a tail, two legs, and two wings.
• Examples: sparrows, eagles, robins, and ostriches.