Year 8 - Science - Biology - Humans as organisms

What is a balanced diet?

A diet that includes a wide variety of foods to provide all the necessary nutrients.

Name the nutrients needed by the body.

Carbohydrates, proteins, fats, vitamins, minerals, water, and fibre.

Why are carbohydrates important for the body?

They provide energy.

What are good sources of starchy carbohydrates?

Pasta, bread.

How do proteins help the body?

They are needed for growth and repair.

List some good sources of protein.

Meat, fish, nuts.

What is the role of fats in the body?

They store energy and insulate the body.

Which foods are rich in fats?

Milk, cream, butter.

Why are vitamins essential for health?

They are necessary for various bodily functions.

Give examples of foods that contain vitamins.

Fruits and vegetables.

What is the importance of minerals in the body?

They are essential for health.

Name some foods that are good sources of minerals.

Fruits, vegetables, dairy products.

How does fibre benefit the digestive system?

It maintains a healthy digestive system.

What foods are high in fibre?

Wholemeal bread, cereals.

Why is water crucial for health?

It dissolves substances and fills cells.

How can you test for the presence of protein in food?

Mash food with water, add biuret solution, wait for a color change to purple.

What indicates a positive result in a glucose test?

A color change from blue to green, yellow, or red.

Describe the method to test for starch in food.

Place iodine solution on the food

How can you detect fat in food?

Rub food on filter paper

What is digestion?

The process of breaking down food into small molecules for absorption.

How do villi aid in absorption during digestion?

They increase the surface area for absorption.

What are enzymes and their role in digestion?

Enzymes are chemicals that speed up reactions and break down food.

Explain the mechanical and chemical processes of digestion.

Mechanical: chewing. Chemical: enzymes

What are the three main types of microorganisms that cause disease?

Bacteria, fungi, viruses.

Define a pathogen.

A microorganism that causes disease.

How do bacteria reproduce?

By growing and dividing into two.

What conditions do bacteria need to grow?

Food, warmth, moisture.

How do fungi obtain their food?

By decomposing living or decaying tissue.

Describe how viruses cause diseases.

By invading and destroying host cells.

Give examples of diseases caused by bacteria, fungi, and viruses.

Bacteria: food poisoning

How can lifestyle choices lead to diseases?

Poor diet, lack of exercise, smoking, etc.

What is a genetic disease?

A disease caused by abnormalities in DNA.

What is the first line of defence against disease?

Skin, mucus, tears.

How do phagocytes protect the body?

By engulfing and digesting pathogens.

What is the role of lymphocytes in the immune response?

Producing antibodies to fight pathogens.

How do antibodies help in fighting pathogens?

They stick to pathogens, causing them to clump and marking them for destruction.

What are the main functions of the skeleton?

Support, protection, movement, blood cell production.

How do muscles and bones work together to allow movement?

Muscles contract and pull on bones.

What is an antagonistic pair of muscles?

Muscles that work in pairs to move joints in opposite directions.

Describe the structure and function of a joint.

Joints connect bones and allow movement

What is the role of the synovial fluid in a joint?

It lubricates the joint.

How does the synovial capsule function in a joint?

It produces and retains synovial fluid.

What are the symptoms of arthritis?

Joint pain, stiffness, swelling, reduced movement.

What is the significance of the bone marrow in the skeleton?

It produces new blood cells.

How does the body transmit diseases through air?

Through sneezes, coughs, etc.

What is the function of mucus in the respiratory system?

It traps microbes and prevents them from entering the lungs.

How do tears protect the eyes from infection?

They contain enzymes that kill bacteria.

What is the advantage of humans evolving to walk on two legs?

Better visibility, energy efficiency, free hands, etc.

How do humans and chimpanzees share a common ancestor?

They evolved from a common species.

What is the role of larger brains in human evolution?

More complex tool use and social interaction.