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.


70. In the systematic naming of enzymes, assume an enzyme is designated as EC 3.4.11.1. Which of the following correctly describes this enzyme?

  1. 11 - gives a sub-subclass to which the enzyme belongs.
  2. 1 - a reference of Enzyme Commission.
  3. 4 - shows to which main class the enzyme belongs.
  4. 3- indicates a subclass to which the enzyme belongs.


71. Consider the following diagram demonstrating the pyramid of energy.
1
Which of the following is INCORRECT about the above pyramid of energy?

  1. The organisms of each trophic level use large proportion of the energy to build their body.
  2. The organisms of the first trophic level convert light energy into chemical energy.
  3. The energy lost as heat to the surrounding in each trophic level is insignificant.
  4. The amount of energy transferred through the trophic levels drops with each step up of the pyramid.


72. Which one of the following is correct about DNA? It is

  1. smaller molecule and coding for only protein.
  2. made of phosphate, sugar and bases.
  3. a single stranded molecule.
  4. less stable and degrades quickly.


73. Industries in the medicine sector use glucose oxidase in clinistix strips for

  1. restoring blood supply to area of heart muscle.
  2. detecting toxic metabolites in the blood.
  3. easy diagnosis of diabetes by examining a urine sample.
  4. reducing the viscosity of mucus.


74. Which one of the following sentences explains the lock-and-key model of enzyme action? The

  1. attached substrate- the enzyme complex enters into a transition state.
  2. model explains enzyme inhibition in a complete manner.
  3. shapes of the substrate is complementary to the active site.
  4. attachment of substrate to an enzyme produces a conformational change.


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!

Connect with us!

MetaAppz Facebook Page MetaAppz Twitter Page MetaAppz Pinterest Page MetaAppz Youtube Page