Biology 2015 E.C - 2023 G.C 2014 E.C - 2022 G.C Chemistry 2015 E.C - 2023 G.C Civics and Ethical Education 2015 E.C - 2023 G.C English 2015 E.C - 2023 G.C Geography 2015 E.C - 2023 G.C History 2015 E.C - 2023 G.C Physics 2015 E.C - 2023 G.C Biology - Grade 12 -2023 G.C Grade 12 students can now access their exam results by visiting the Educational Assessment and Examination Services (EAES) website. Previous123456789101112131415161718192021Next 80. Which of the following plant adaptation mechanisms helps cactus to adapt in the desert environment? Spreading its seeds in wider areas Increasing number of stomata in its leaves Having broad leaves Storing water in its tissue 81. A student has conducted an experiment using different enzymes to assess the enhancement of reaction rates under different conditions. She represents her results as indicated in the following table.Enzymes usedCofactors usedRate enhancementsOptimum temperature required °C XZn++1.4 x 101737YCu++7.7 x 10645ZNo cofactors4.6 x 10528MCo++1.7 x 10830Which one of the following is an acceptable conclusion of the experiment? Enzyme 'X' could have enhanced the rate better at temperature slightly higher than 37°C. Enzyme 'M' cannot enhance the rate of reaction further if the temperature exceeds 30°C. The rate enhancement for enzymes 'Z' is less because it didn't use a cofactor. As temperature increases the rate of chemical reaction decreases. 82. Which one of the following sentences correctly describes the properties of water? It contracts when it freezes and ice acts as an insulator. takes low energy to change into vapor. allows all light wavelengths to pass through its various depths. requires high amount of energy to heat up. 83. An organic molecule which is an important part of structure of chromosome is amino acid. glycogen. amylose. triglyceride. 84. In animal cells, glycogen is hydrolyzed quickly to release glucose for respiration. This is due to the presence of several microfibrils in its side chain. α-1,6-glycosidic bonds. β-1,4-glycosidic bonds. enzymes that hydrolyse it easily. Previous123456789101112131415161718192021Next We have provided these questions from previous years grade 12 Ethiopian Secondary School Leaving Certificate Examination (ESSLCE) exams with the sole purpose of assisting students in their studies and preparations for upcoming exams. Please be aware that these questions are not indicative of future exam content. Good luck with your studies!