Explanation

• When a person inhales, the air travels through the nose or mouth, into the larynx and then into the trachea; which is the main passageway into the lungs.
• The trachea divides into a right and left bronchi.
• Bronchi branch into smaller tubes that become bronchioles.
  

Explanation

• Insulators are materials that resist the flow of electricity, such as rubber, glass, wood, and plastic.
• They have a high resistance to electric current and are used to prevent the flow of electricity.

Explanation

When you put sand, salt, and sawdust in a glass of water, the following things happen:

• Salt dissolves in water, meaning it breaks down into individual particles that are distributed evenly throughout the water.
• Sand sinks to the bottom of the glass, because it is denser than water and cannot float or dissolve in it.
• Sawdust floats on top of the water, because it is less dense than water and is able to remain suspended on the surface.

Explanation

• If the number of frogs increases, it is likely that the number of snakes would decrease.
• This is because snakes are predators that feed on frogs, and an increase in frog population would lead to a decrease in snake population due to competition for resources and potential overgrazing.

Explanation

Iron is an essential mineral that plays a crucial role in:

• Producing red blood cells (hemoglobin)
• Oxygen transport (binding to oxygen in lungs and releasing it to tissues)
• Energy conversions (supporting cellular metabolism)

Explanation

Vitamin C is essential for: Strengthening the immune system and Preventing Scurvy, a disease characterized by:

• Fatigue and weakness
• Bleeding gums and loose teeth
• Joint pain and swelling
• Poor wound healing

Vitamin C is important for:

• Collagen production
• Iron absorption
• Antioxidant functions
• Supporting white blood cell function

Explanation

• Fat provides approximately twice as much energy as the same amount of carbohydrate.
• This is because fat contains approximately 9 kcal/g (kilocalories per gram).
• Carbohydrate contains approximately 4 kcal/g.

Explanation

• Plants absorb Carbon Dioxide (CO2) during the daytime through tiny openings on their leaves called stomata.
• They use this carbon dioxide, along with water (H2O) and light energy from the sun, to produce glucose (C6H12O6) and oxygen (O2) through the process of photosynthesis.

Explanation

• The skeleton and muscles work together to support your body and move it forward.
• The skeleton provides the structural framework and support.
• The muscles contract and relax to move the bones and facilitate movement.

Explanation

• Omnivores can be both secondary and tertiary consumers, depending on their diet and position in the food chain.
• They can eat primary consumers (herbivores) as secondary consumers, and also eat secondary consumers (other carnivores or omnivores) as tertiary consumers.