The table below shows the predator/prey relationship over a five (5) year period.

Step 1: Answer Question 43. To investigate photosynthesis, plants are destarched by keeping them in the dark. After exposure to sunlight, starch is produced. When iodine solution is used to test for starch, it changes from its original orange/brown color to dark blue or blue-black in the presence of starch. The correct answer is B. B Step 2: Answer Question 44. The graph shows that the rat's body temperature remains constant regardless of changes in external temperature. This characteristic describes a homoiothermic (or homeothermic) animal, which maintains a stable internal body temperature. The correct answer is C. C Step 3: Answer Question 45. Anaemia is often caused by a deficiency in iron. To prevent anaemia, one should consume food rich in iron. From the table, Food Q has the highest iron content at 1.5 mg. The correct answer is Q. Q Step 4: Answer Question 46. Let 'A' be the dominant allele for black fur/eyes and 'a' be the recessive allele for albinism. An albino male (aa) is crossed with a pure breeding black female (AA). P generation: aa × AA F1 generation: All offspring are Aa (heterozygous black). To get the F2 generation, two F1 individuals are crossed: Aa × Aa. Using a Punnett square: | | A | a | |---|---|---| | A | AA | Aa | | a | Aa | aa | The F2 genotypes are 1 AA : 2 Aa : 1 aa. The F2 phenotypes are 3 black (normal) : 1 albino. The probability of producing a normal F2 offspring is (3)/(4). The correct answer is C. C Step 5: Answer Question 47. Fish suffocate out of water because their delicate gill filaments, which are adapted for gas exchange in water, collapse and stick together in the air. This drastically reduces the surface area available for oxygen absorption, leading to suffocation. The correct answer is B. B Step 6: Answer Question 48. The graph shows that the rate of photosynthesis increases with temperature up to point X, after which it sharply declines. Point X represents the optimal temperature at which the rate of photosynthesis is at its maximum. The correct answer is B. B Step 7: Answer Question 49. A universal donor is a blood group that can donate blood to individuals of all other blood groups. From the provided table, Donor Blood group O is compatible with Recipient Blood groups A, B, AB, and O (marked with 'X' in all columns). The correct answer is D. D Step 8: Answer Question 50. The table shows that the prey population significantly decreased from Year 3 (300) to Year 4 (100) and further to Year 5 (30). Predators rely on prey for food. A drastic reduction in the prey population leads to a lack of enough prey to feed on for the predators, causing their population to drop (from 10 in Year 3 to 4 in Year 4). The correct answer is C. C Last free one today — make it count tomorrow, or type /upgrade for unlimited.