2h-transport Flashcards
Q: Why is a transport system necessary in multicellular organisms?
A: Multicellular organisms need transport systems to move nutrients, oxygen, and waste products efficiently because diffusion alone is too slow over long distances.
Q: How do unicellular organisms transport substances?
A: Unicellular organisms rely on diffusion for transporting substances because their small size allows efficient diffusion across their surface.
Q: How is transport carried out in plants?
A: Transport in plants involves two main tissues:
Xylem: Transports water and minerals from roots to other parts of the plant (unidirectional).
Phloem: Transports sugars (sucrose) and amino acids between leaves and other parts of the plant (bidirectional).
Q: How is transport carried out in humans?
A: The circulatory system, consisting of the heart, blood, and blood vessels, transports oxygen, nutrients, and waste products.
Red Blood Cells: Transport oxygen using hemoglobin.
White Blood Cells: Fight infections (phagocytes engulf pathogens, lymphocytes produce antibodies).
Plasma: Carries nutrients, hormones, and waste products.
Platelets: Help with blood clotting.
What is the structure of the heart, and how does it function?
A: The heart pumps blood through two circuits: pulmonary (to lungs) and systemic (to body).
Left side: Pumps oxygenated blood to the body.
Right side: Pumps deoxygenated blood to the lungs.
How do blood vessels differ in structure and function?
Arteries: Thick walls, carry blood away from the heart under high pressure.
Veins: Thin walls, valves prevent backflow, carry blood toward the heart.
Capillaries: Thin, one-cell-thick walls for efficient diffusion of substances.
What factors affect the risk of developing coronary heart disease?
A: Poor diet (high saturated fat), lack of exercise, smoking, and genetic factors increase the risk of fatty deposits in arteries, leading to heart attacks.
Practical: Investigating Transport in Living Systems
Investigating Water Uptake in Plants:
Method: Place a leafy shoot in a potometer, measure water uptake by observing the movement of an air bubble.
Positive Result: Faster movement indicates higher water uptake.
Negative Result: Little or no movement indicates minimal water uptake.
Practical: Investigating Transport in Living Systems
Investigating Heart Rate in Humans:
Investigating Heart Rate in Humans:
Method: Measure pulse rate at rest, then after exercise.
Positive Result: Pulse rate increases after exercise due to higher oxygen demand.
Negative Result: No change in pulse rate if the person remains at rest.
