Bioaccumulation
1. What is bioaccumulation?
Answer: Bioaccumulation is the build-up of harmful substances in an organism over time.
Define habitat.
The place where an organism lives.
What is blood?
Answer: Blood is a liquid that flows through the body and transports substances like oxygen and nutrients.
State one function of iron in the human body.
Iron is needed to make haemoglobin in red blood cells.
What are the three main chemical elements found in carbohydrates, proteins, and fats?
Carbon, Hydrogen, and Oxygen. (Note: Proteins also contain Nitrogen).
2. What types of substances can bioaccumulate?
Answer: Toxic chemicals like pesticides, heavy metals (e.g. mercury), and pollutants.
Define ecosystem.
An environment that supports life
What is the function of plasma?
Plasma transports substances such as nutrients, hormones, carbon dioxide, and waste products.
Explain what can happen if a person does not get enough iron in their diet.
They may develop anemia, which causes tiredness and weakness.
3: What is the main function of fats (lipids) in the human body?
Energy storage, thermal insulation (keeping us warm), and protecting internal organs.
3. Why do these substances stay in the body?
Answer: They are not easily broken down or removed from the body.
Define interdependence.
When organisms affects the existence of the other organism in an ecosystem.
Why do red blood cells not have a nucleus?
So they have more space to carry oxygen.
Name two food sources that are rich in iron.
Answer: Red meat, liver, spinach, beans, and lentils.
Why does the body need proteins? Mention at least two reasons.
For growth, repairing damaged tissues, and making enzymes and antibodies.
Where do bioaccumulated toxins usually collect in the body?
Answer: In fatty tissues of organisms.
State two biotic factors found in a forest ecosystem.
Any two: plants, animals, fungi, bacteria, insects
Describe what would happen if a person did not have enough platelets.
Their blood would not clot properly, so they would bleed for a long time.
State one role of calcium in the human body.
Answer:
Explain what might happen to bones if the body does not get enough calcium.
Name two foods that are good sources of calcium.
Calcium is important for strong bones and teeth.
Bones can become weak and brittle, leading to conditions like osteoporosis.
Milk, cheese, yogurt, and leafy green vegetables.
Explain why a marathon runner might eat a large bowl of pasta the night before a race, but a bodybuilder might focus on eating chicken and eggs.
Pasta is rich in starch (complex carbohydrate), which is broken down into glucose to provide a sustained energy source for the race. Chicken and eggs are high in protein, which provides the amino acids necessary for muscle repair and growth after heavy lifting.
Where do bioaccumulated toxins usually collect in the body?
Answer: In fatty tissues of organisms.
A river becomes polluted and many fish die.State whether pollution is a biotic or abiotic factor and explain
Abiotic
Explain how white blood cells protect the body.
They destroy pathogens by engulfing them or by producing antibodies.
State one function of vitamin A.
Explain how a lack of vitamin A can affect the eyes.
Give two food sources rich in vitamin A.
Answer: Vitamin A helps with good vision, especially in dim light.
It can lead to night blindness or poor vision in low light.
Carrots, sweet potatoes, liver, and eggs.
Compare the energy content of 1 gram of fat versus 1 gram of carbohydrate.
Fat contains significantly more energy per gram (roughly double) than carbohydrates. This is why fats are used for long-term storage, while carbohydrates are used for immediate use.