In a scientific investigation, which step should come immediately after identifying a clear problem?
Experimental Design
Question · Easy
The houseplant does both
Short
A learner tests how light intensity affects the rate of photosynthesis in an aquatic plant. What is the independent variable?
Question · Medium
Which food-test reagent is heated with a sample and turns from blue towards brick-red if a reducing sugar is present?
A leaf is boiled in water, then in ethanol, rinsed, and flooded with iodine. A blue-black colour in the lamina means the leaf contained which stored carbohydrate?
A compound light microscope has a ×10 eyepiece and a ×40 objective in use. What is the total magnification of the image?
Potato cylinders of equal length are placed in sucrose solutions of different concentrations. After one hour the cylinder in distilled water is longest and the cylinder in concentrated sucrose is shortest. Which process best explains the results?
Question · Hard
Which practice is required by scientific research ethics when people take part in a Biology investigation?
When preparing a temporary slide of onion epidermis, why is iodine solution often added?
Which organelle is the main site of aerobic respiration and ATP production in a plant or animal cell?
Cell Biology
Which structure is found in a typical plant cell but not in a typical animal cell?
A bacterial cell is described as prokaryotic mainly because it lacks which feature?
Root-hair cells absorb water and mineral ions. Which adaptation is most directly linked to that function?
Which process moves oxygen from a region of higher concentration in an alveolus into blood plasma without using ATP?
A red blood cell is placed in a concentrated salt solution. What happens to the cell?
Mineral ions often enter root-hair cells against their concentration gradient. Which process is responsible?
An enzyme-controlled reaction is fastest at 37 °C and almost stops at 70 °C, even after the mixture is cooled. Why does cooling fail to restore activity?
Which statement correctly describes enzymes?
Which pair correctly matches a chemical of life with its usual monomers?
What is the main biological role of mitosis in a human body?
During which stage of mitosis do sister chromatids separate and move to opposite poles?
Which nutrient is used mainly as a structural material for growth and tissue repair in humans?
Nutrition
A child with a swollen abdomen, thin limbs and very low protein intake is most likely showing which deficiency condition?
Nitrogen, phosphorus and potassium are described as plant macronutrients because they are needed in relatively large amounts. A shortage of nitrogen commonly causes which symptom?
Which word equation correctly represents photosynthesis?
Photosynthesis
Which leaf tissue contains the highest density of chloroplasts and is the main photosynthetic layer?
A destarched plant has one leaf enclosed in a foil envelope and another left uncovered. After several hours of light, only the uncovered leaf tests positive for starch. What does this show?
In the light-dependent stage of photosynthesis, what is the source of the oxygen gas released?
Saprophytic nutrition is best illustrated by which organism?
Which type of human tooth is specialised for cutting food?
Where is maltase produced and what reaction does it catalyse?
Which liver function correctly matches the process named?
Villi in the small intestine increase the rate of absorption. Which combination of features does that?
Which word equation represents aerobic respiration?
Respiration
During vigorous exercise, human muscle may respire anaerobically. What is the characteristic product?
Compared with inspired air, expired air from a resting person usually contains
Which everyday industry depends on anaerobic respiration by yeast?
Which tissue transports water and mineral ions from roots to leaves?
Transport
Which statement about transpiration is correct?
Which component of blood is mainly responsible for transporting oxygen?
Why is the wall of the left ventricle thicker than the wall of the right ventricle?
Which description matches an artery rather than a vein?
Blood in the pulmonary vein is unusual among veins because it is
A person of blood group O can safely donate red cells, in a simple ABO match, to which recipients?
In the clotting cascade taught at this level, thrombin catalyses which conversion?
Which comparison of single and double circulation is correct?
Which function belongs to the lymphatic system?
Which organ produces urea and which organ excretes most of it?
Excretion
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