Diffusion

To transport substances such as oxygen, nutrients, hormones, and waste products around the body.
Explanation: The circulatory system ensures that all cells receive what they need and waste is removed efficiently.

Carbohydrates
Explanation: Carbohydrates (e.g., rice, bread, pasta) are broken down into glucose, which provides energy for body cells.

Photosynthesis

A microorganism that causes disease, such as bacteria, viruses, fungi, or protozoa.
Explanation: Pathogens are harmful organisms that can invade the body and make you sick.

1) Concentration gradient. 2) Temperature

Red blood cells (RBCs): Carry oxygen from the lungs to body cells.

White blood cells (WBCs): Fight infections and protect the body.

Platelets: Help in blood clotting to prevent bleeding.
(Plasma can also be mentioned: carries nutrients, hormones, and waste.)

Vitamin A: Maintains healthy eyesight and skin.

Vitamin C: Helps in wound healing and strengthens the immune system.
(Other acceptable answers: Vitamin D for strong bones, Vitamin K for blood clotting)

Root: Absorbs water and minerals from the soil.

Stem: Supports the plant and transports water and nutrients.

Leaf: Carries out photosynthesis.

Infectious disease: Caused by pathogens. Example: Influenza (flu).

Non-infectious disease: Not caused by pathogens. Example: Diabetes.
Explanation: Infectious diseases can spread between people; non-infectious diseases cannot.

Active transport moves molecules against their concentration gradient and requires energy (ATP).

Facilitated diffusion moves molecules down their concentration gradient through a protein channel and does not require energy.

Arteries: Carry blood away from the heart, have thick, muscular walls to withstand high pressure.

Veins: Carry blood towards the heart, have thin walls and valves to prevent backflow.

Capillaries: Very thin walls (one cell thick), allow exchange of materials (oxygen, nutrients, waste) between blood and body cells.

Macronutrients: Needed in large amounts for energy and growth. Examples: carbohydrates, proteins, fats.

Micronutrients: Needed in small amounts for proper body function. Examples: vitamins and minerals.

Xylem: Transports water and minerals from the roots to the leaves.

Phloem: Transports food (glucose) from the leaves to other parts of the plant.

Innate immunity: The body’s first line of defense, acts immediately against pathogens. Example: Skin, stomach acid.

Adaptive immunity: Specific response to a pathogen, develops over time and has memory. Example: Antibodies produced after vaccination or infection.

The cell was in a hypertonic solution (higher solute concentration outside the cell).

Reason: Water moves out of the cell by osmosis to balance solute concentrations, causing the cell to shrink.

Atria: The upper chambers receive blood — right atrium from the body, left atrium from the lungs.

Ventricles: The lower chambers pump blood out — right ventricle to the lungs, left ventricle to the rest of the body.
Explanation: The heart works as a double pump, sending blood to the lungs for oxygenation and then to the body to deliver oxygen.

Enzymes speed up the breakdown of food molecules into smaller, absorbable forms.

Example: Amylase in saliva breaks down starch into maltose.

Pollination: Transfer of pollen from the anther (male) to the stigma (female) of a flower.

Fertilization: When the male gamete (from pollen) fuses with the female gamete (ovule) to form a zygote, which develops into a seed.

Vaccines contain dead or weakened pathogens or parts of them.

They stimulate the immune system to produce antibodies without causing illness.

If the real pathogen enters later, the body can respond quickly and prevent infection.

Endocytosis: The cell takes in large molecules by folding the cell membrane around them to form a vesicle.

Exocytosis: The cell removes large molecules by fusing a vesicle with the cell membrane to release them outside.

Oxygen enters the blood in the lungs (from inhaled air) and binds to red blood cells.

The circulatory system carries oxygen-rich blood to body cells.

Cells release carbon dioxide as a waste product, which diffuses into the blood.

Blood carries carbon dioxide back to the lungs, where it is exhaled.
Explanation: This shows the close link between the circulatory and respiratory systems in maintaining gas exchange.

A balanced diet provides all nutrients in the correct amounts needed for energy, growth, repair, and body functions.

Deficiency example: Lack of vitamin D can lead to rickets (weak bones), and lack of iron can cause anemia (reduced oxygen transport).
Explanation: Each nutrient plays a specific role, so imbalance can cause health problems.

Adaptations:

Thick waxy cuticle to reduce water loss.

Small or spiny leaves to minimize surface area for transpiration.

Deep or widespread roots to access water.

Examples: Cactus, Aloe Vera
Explanation: These adaptations help the plant survive in arid conditions where water is scarce.

Phagocytes: Cells that engulf and digest pathogens during the first response.

Antibodies: Proteins that bind to specific pathogens to neutralize or mark them for destruction.

Memory cells: Remain in the body after infection or vaccination and provide long-term immunity by responding rapidly if the pathogen returns.
Explanation: These three components work together to detect, destroy, and remember pathogens, forming the basis of immunity.