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Repost from QUBEE ACADEMY
History 2md Round Model Exam Result 👇👇👇
https://docs.google.com/forms/d/e/1FAIpQLScnH1_W1-JCWeEw5oo_iPaPl0g7j3QwkYbqpuZuJJfdUrlryw/viewform?usp=dialog
| 2 | Economics 2nd Round Model Exam Result
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| 3 | Biology 2nd Round Model Exam Result
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| 5 | 2018 Maths G-12 2nd sem competition.pptx | 146 |
| 6 | English Language Competition questions for grade 12 students.ppt | 146 |
| 7 | +8 Join our telegram channel @ethio_new_curriculum
Website for short notes and practice questions for all subjects from grade 9 to 12 | 153 |
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| 9 | http://Mock1.ethernet.edu.et | 280 |
| 10 | 6. Unit Six
🚩Environmental Biology
🥕Population Ecology
🥕Population Size and Density
🥕Population Growth Models
🥕Demography
🥕Human Population Dynamics
🥕Natural Resources
🥕Environmental Impact & Sustainability
Biology Grade 12 Topic
Unit One
🚩Microorganisms
🥕Bacteria
🥕Ecology and Uses of Bacteria
-Ecological Role
-Industrial Importance
-Agricultural Importance
🥕Viruses
-Nature of Viruses
-Structure of virus
-Viral Reproduction
Unit Two
🚩Microorganisms
🥕Introduction to Microorganisms
🥕Classification and Diversity
🥕Eubacteria
🥕Nutritional Types( phototrophs, chemotrophs, and heterotrophs)
🥕Protozoa: Explores the features of protozoans (like Amoeba, Euglena, and Paramecium), their nutrition, reproductive modes (sexual and asexual), and mechanisms like conjugation
🥕Health and Economic Impacts( diseases caused by protozoan parasites, their modes of transmission)
Unit Three
🚩Energy Transformation.
🥕Introduction to Metabolism
🥕Photosynthesis
-Light-Dependent Reactions
-Light-Independent Reactions (The Calvin Cycle
🥕Cellular Respiration( Four Stages of Aerobic Respiration: Glycolysis, the transition reaction (pyruvate oxidation), the Krebs (Citric Acid) Cycle, and oxidative phosphorylation.
Fermentation:
🥕Ecological Significance
Unit Four
🚩 Evolution
🥕The Origin of Life:
🥕Theories of Evolution:
🥕Evidences of Evolution
🥕The Process of Evolution
🥕The Evolution of Humans
🚩Mutation
🥕Type, cause and effect of Mutation
🚩The Bottleneck Effect
🚩The Founder Effect
🚩Hardy-Weinberg Equilibrium
Unit Five
🚩the Human Nervous System.
🥕The Central Nervous System
🥕The Peripheral Nervous System
🥕Neurons and Synapses
🥕Sensory Receptors:
🥕
Unit Six
🚩Climate Change
🥕Causes of Climate Change
🥕The Greenhouse Effect
🥕Impacts on Biodiversity
🥕Mitigation and Adaptation
🥕
🥕 | 375 |
| 11 | Biology Grade 9
1. Unit One
🚩Biology and Technology
🥕Renowned Ethiopian BiologistsThis section
🥕Biological Research in Ethiopia( Agricultural Advancements, Healthcare and Medicine, Environmental Conservation)
2. Unit Two
🚩Characteristics and Classification of Organisms
🥕Characteristics of Living Things
🥕Taxonomy and Classification
🥕The Five Kingdom System( Monera , Protista, Fungi, Plantae, Animalia)
🥕Micro-organisms and Viruses
🥕
3. Unit Three
🚩Cells
🥕What is a Cell?:
🥕Scientists Behind the Cell Theory
🥕Cell Structure and Function:
🥕Plant vs. Animal Cells:
🥕
4. Unit Four
🚩Reproduction
🥕Introduction to Reproduction
🥕Asexual Reproduction( Fission, Fragmentation,Budding, Vegetative propagation
🥕Sexual Reproduction in Humans( Sexual Characteristics, Reproductive Anatomy, The Menstrual Cycle, Fertilization and Pregnancy
🥕Reproductive Health & Disease (Birth Control: Methods ,STIs,
🥕
5. Unit Five
🚩Human Health, Nutrition, and Disease
🥕What is Food & Nutrition
🥕Nutrient Groups
🥕Balanced Diet:
🥕Human Health
🥕Infectious vs. Non-infectious Diseases
6. Unit Six
🚩Ecology
🥕Ecosystems and Ecological Levels (Biotic vs. Abiotic Components ,Ecological Levels,
🥕Habitats and Niches
🥕Energy Flow and Ecological Relationships(Food Chains and Webs: ,Ecological Pyramids, Symbiotic Relationships
🥕Ecological Succession and Environment (Succession, Human Impacts)
🥕
Biology Grade 10 Topic
Unit One
🚩Sub-fields of Biology.
🥕What is Biology?
🥕Pure Fields of Biology( Zoology, Botany, Microbiology, Genetics, Ecology)
🥕Applied Fields of Biology( Biotechnology, Medicine and Pharmacy,Agriculture, Environmental Conservation
🥕Interconnectedness
🥕
Unit Two
🚩Plants
🥕Characteristics of Plants
🥕Flowering and Non-Flowering Plants
🥕Structure and Function of Plant Parts
🥕Reproduction and Life Cycles
🥕Plant Transport Systems
Unit Three
🚩Biochemical Molecules.
🥕Inorganic Compounds
🥕Organic Biochemical Molecules( Carbohydrates, Lipids, Proteins, Nucleic Acids)
🥕Biochemical Tests: Practical methods for identifying biological molecules in the laboratory (e.g., Benedict's test for reducing sugars and the Biuret test for proteins)
🥕
🥕
Unit Four
🚩Cell Reproduction
🥕The Cell Cycle
🥕Cell Division( Mitosis, Meiosis)
🥕Renowned Ethiopian Geneticist
🥕
Unit Five
🚩Human Biology
🥕Ingestion , Digestion, Absorption , Egestion
🥕The Circulatory and Lymphatic Systems( The Heart and Blood Vessels:, Blood Components, The Lymphatic System
🥕Related Diseases and Disorders( Digestive Disorders, Circulatory/Lymphatic Diseases,
🥕
🥕
Unit Six
🚩Ecological Interactions
🥕Trophic Levels, Food Chains and Food Webs, Trophic Levels, Ecological Pyramids
🥕Cycling of Materials in an Ecosystem( The Water Cycle, Carbon cycle, The Nitrogen Cycle, The Phosphorus Cycle
🥕
Biology Grade 11
1. Unit One
🚩Biology and Technology
- Learning From Nature
-Biomimetics
-Ecosystem Models
-🥕Biology and Technology
-Biotechnology
- Bioinformatics
🥕Relevance and Ethical Considerations
-Societal Impact
-Environmental/Ethical Concerns
2. Unit Two ( Animals)
- Characteristics of Animals
-Invertebrates and Vertebrates
-Reproduction in Animals
-Economic Importance of Animals
--Animal Behavior
--Homeostasis in Animals
--Renowned Zoologists in Ethiopia
3. Unit Three
🚩Enzymes
--Nature of Enzymes:
--Protein Structure
--Enzyme-Substrate Models
--Factors Affecting Enzyme Action
--Enzyme Inhibition
-- Enzyme Classification & Co-factors
--Industrial & Traditional Applications
4. Unit Four
🚩Genetics
🥕The Genetic Materials
🥕DNA Replication & Protein Synthesis
🥕The Cell Cycle and Cell Division
🥕Mendelian Genetics
🥕Non-Mendelian Inheritance
🥕Applied Genetics( Applied Genetics: An overview of genetic engineering, selective breeding in agriculture, and bioinformatics
5. Unit Five
🚩The Human Body Systems
🥕The Human Musculoskeletal System
🥕The Digestive System and Nutrition
🥕Respiratory System
🥕Circulatory and Lymphatic Systems
🥕Nervous System and Sensory Organs:
🥕Endocrine System
🥕Human Reproductive System and Health: | 295 |
| 12 | 97. Given the following parts of the body, the hormone ADH and action taken by the kidney as follows
I. Osmoreceptors in the brain IV the second coiled tubules of the kidneys
II. More water is reabsorbed V. Pituitary gland
III. ADH released
What is the correct sequence of osmoregulatory process carried out in the body if the water content of the blood is too low? [ G 11 Unit Five The Human Body Systems : The Human Excretory system 🖍]
A. I, V, IV, III, II C. I, III, IV, V, II
B. I, V, III, IV, II D. I, II, V, III, IV
Answer: D
Explanation:
The correct sequence of the osmoregulatory process is
I. Osmoreceptors in the brain detect that the water content of the blood is too low (high solute concentration).
V. The pituitary gland is stimulated to release a hormone.
III. ADH (antidiuretic hormone) is released into the bloodstream and travels to the kidneys.
IV. The second coiled tubules (distal convoluted tubules) and collecting ducts of the kidneys are made more permeable by the ADH.
II. More water is reabsorbed from the kidney tubules back into the blood, producing a smaller volume of concentrated urine and restoring water levels
98. How does increased use of fossil fuels by humans linked to global warming? Fossil fuels: [ G 12 Unit Six Climate Change 🖍]
A. release oxygen which has a cooling effect
B. increase CO₂ that traps heat energy.
C. form cloud which has a dimming effect
D. release ethanol which cause global warming
Answer: B
Explanation : When humans burn fossil fuels like coal, oil, and natural gas for energy, they release massive amounts of carbon dioxide and other greenhouse gases into the atmosphere. These gases allow sunlight to pass through to the Earth's surface but prevent the resulting heat from escaping back into space. This phenomenon, known as the greenhouse effect, is the primary driver of rising global temperatures.
99. In a dry region, prolonged drought reduces crop yield and causes migration of herbivores. How can you explain the combined biological impact of this given phenomenon? [G 12 Unit Six Climate Change 🖍]
A. Increased rainfall disrupts food chains
B. Animals adapt instantly to new climates
C. Plants support animals during drought season
D. Reduced water disrupts food webs and survival.
Answer: D
Explanation: Water is the foundational abiotic factor for all ecosystems in dry, arid regions. Prolonged drought limits plant growth and destroys vegetation, removing essential primary producers from the ecosystem. Without these food sources and hydration, primary consumers (herbivores) are forced to migrate or face starvation. This loss of producers and subsequent migration disrupts the entire interconnected network of feeding relationships, known as a food web, negatively impacting the survival of multiple species.
100. How does the Great Ethiopian Renaissance Dam contribute to climate change mitigation? [ G 12 Unit Six Climate Change 🖍]
A. By providing carbon dioxide free energy.
B. By consuming more fossil fuels
C. By making our earth greener.
D. By releasing more oxygen to the atmospher
Answer: A
Explanation
As a massive hydroelectric project, the GERD generates thousands of megawatts of clean, renewable electricity. The Great Ethiopian Renaissance Dam (GERD) contributes to climate change mitigation primarily through by providing carbon dioxide free energy. | 215 |
| 13 | 93. Initial refraction of light and controlling the amount of light entering the eye respectively are the functions of [ G 11 Unit Five The Human Body Systems : The Human Eye🖍]
A. Lens and Pupil
B. Conjunctiva and Retina
C. Sclera and Choroid
D. Cornea and Iris
Answer: D
Explanation
✅ Cornea: This is the transparent, dome-shaped front layer of the eye where initial refraction (bending) of light occurs as it enters.
✅ Iris: This is the colored part of the eye that controls the amount of light entering by adjusting the size of the pupil.
94. A student has difficulty hearing faint sounds after middle ear damage by an accident. Which of the following statement best explains such hearing problem? [ G 11 Unit Five The Human Body Systems : The Human Ear 🖍]
A. Eardrum does not form nerve impulses
B. Cochlea stops receiving sound waves
C. Ossicles fail to amplify vibrations
D. Auditory nerve stops vibrating
Answer: C
Explanation:The auditory ossicles are three tiny bones in the middle ear (the malleus, incus, and stapes). Their primary function is to transmit and significantly amplify sound vibrations as they travel from the eardrum to the inner ear's fluid-filled cochlea. Damage to the middle ear typically disrupts this mechanical process, causing conductive hearing loss where soft or faint sounds cannot be adequately boosted, making them difficult to detect.
95. If a patient suffers from low blood glucose levels in the blood, which gland and hormone are affected in his/her body? [ G 11 Unit Five The Human Body Systems : The Endocrine System 🖍]
A. Calcitonin secretion by thyroid gland
B. PTH secretion by parathyroid gland
C. Glucagon secretion by pancreas gland
D. Thyroxin secretion by thyroid gland
Answer: C
Explanation
♦️Gland: The pancreas contains specialized clusters of cells called the islets of Langerhans.
♦️Hormone: The alpha cells in these islets secrete glucagon, which signals the liver to break down stored glycogen into glucose and release it into the bloodstream.
96. Part of a human kidney where all of the glucose is actively taken back into the blood along with around 67% of the sodium ions and around 80% of the water is [ G 11 Unit Five The Human Body Systems : The Human Excretory system 🖍]
A. Bowman’s capsule
B. Loop of Henle
C. Second coiled tubule
D. First coiled tubule
Answer: D
Explanation
The first coiled tubule is the primary site of selective reabsorption in the human nephron. In this region, roughly 67 %of sodium ions and 80 % of water are returned to the bloodstream, alongside the active transport reabsorption of all glucose and amino acids. | 211 |
| 14 | 87. A grade 12 biology student observes a neuron under a microscope and notices many short branched projections surrounding the cell body. What is the main role of this structure? [G12 Unit Five Human Body Systems & Homeostasis & Neurons and Synapses🖍]
A. Carry impulses away from the neuron
B. Receive signals from other neurons
C. Produce myelin around the axon
D. Connect neurons to muscle fibers
Answer: B
Explanation
The short, branched projections surrounding the cell body are called dendrites.
88. In a neuron, neurotransmitters are chemicals released when an impulse reaches the axon terminal. What is the immediate role of these chemicals? [G12 Unit Five Human Body Systems & Homeostasis & Neurons and Synapses🖍]
A. Produce electrical insulation around the axon
B. Repair damaged nerve fibers
C. Trigger impulses in the next cell
D. Carry oxygen into the neuron
Answer: C
Explanation : When an electrical impulse reaches the axon terminal, neurotransmitters are released into the synapse (the gap between neurons). These chemicals bind to receptors on the adjacent cell, triggering a new electrical impulse in that cell to continue the signal's path.
89. Which of the following is not part of the peripheral nervous system in the human body?[ G12 Unit Five Human Body Systems & Nervous System 🖍]
A. spinal cord
B. somatic nervous system
C. autonomic nervous system
D. sympathetic nervous system
Answer: A
Explanation : The spinal cord is not part of the peripheral nervous system (PNS); instead, it is a primary component of the central nervous system (CNS), along with the brai
90. Which of the following best defines a reflex action? It is G12 Unit Five Human Body Systems & Homeostasis & Neurons and Nerves 🖍]
A. sudden increase in the nerve impulse transmission due to high insulin production.
B. uncontrolled response of the body coordinated by the brain during sleeping.
C. uncontrolled production of neurotransmitters in the human body.
D. automatic response of parts or the whole body to the external stimuli.
Answer: D
Explanation : A reflex action is a rapid, involuntary, and automatic response to a specific sensory stimulus. It allows the body to react swiftly to potential danger (like pulling your hand away from a hot stove) without waiting for the brain to process the information.
91. Which of the following is the function of the dermis layer of your skin? It [G 11 Unit Five The Human Body Systems : Integumentary system 🖍]
A. provides a waterproof barrier.
B. produces sweat and oil
C. produces the melanin pigment.
D. stores fat that prevent heat loss.
Answer: B
Explanation : Production of Sweat and Oil: The dermis contains sweat glands (which help with temperature regulation) and sebaceous glands (which produce oil, or sebum, to keep the skin lubricated).
♦️Epidems: provides a waterproof barrier, produces the melanin pigment.
♦️Hypodermis - stores fat that prevent heat loss
92. The next item is based on the following figure[ G 11 Unit Five The Human Body Systems : The Human Eye🖍]
In the above human eye diagram, letter ‘A’ and letter ’B’ respectively represents
A. Pupil and Choroid
B. Cornea and Optic nerve
C. Lens and Retina
D. Sclera and Choroid
Answer: B | 171 |
| 15 | 82. An Ethiopian national museum team who is working with other country’s museum teamwants to arrange fossils to illustrate the major stages of human evolution. Which sequence would best demonstrate increasing bipedalism and brain size?
G12 Unit Four Evolution: Human evolution 🖍]
A. Ardi → Lucy → Homo erectus → Homo sapien
B. Lucy → Ardi → Homo sapiens → Homo erectus
C. Homo sapiens → Lucy → Ardi → Homo erectus
D. Homo erectus → Homo sapiens → Lucy → Ardi
Answer,: A
Explanation : This sequence accurately represents the chronological timeline and the progression of human evolution.
🥕Ardipithecus ramidus (Ardi, ~4.4 million years ago)
🥕Australopithecus afarensis (Lucy, ~3.2 million years ago) were early, smaller-brained hominins that demonstrated the beginnings of bipedalism.
🥕Homo erectus (~1.8 million years ago) represents a major leap in brain size and tool use, leading up to modern Homo sapiens with the largest relative brain size.
83. All of the following are the cause of an induced mutation EXCEPT? [G12 Unit Four Evolution: Mutation (Type, cause and effect of Mutation🖍]
A. UV- radiations
B. Chemical substances
C. tobacco smoke
D. error during DNA replication
Answer,: D
Explanation: Induced mutations are caused by external environmental factors known as mutagens (such as UV radiation, chemical substances, and tobacco smoke). An error during DNA replication is considered a spontaneous mutation because it happens naturally within the cell during normal cellular processes, not from an outside mutagen.
84. The type of mutation that results in a Down syndrome disorder is classified as G12 Unit Four Evolution: Mutation (Type, cause and effect of Mutation🖍]
A. inversion chromosomal mutation
B. aneuploidy
C. frame shift mutation
D. point mutation
Answer,: B
Explanation: Down syndrome is generally caused by an error in cell division called nondisjunction, which results in the cell having an abnormal number of chromosomes.
🚩Because the individual has an extra copy of chromosome 21 (resulting in 47 chromosomes instead of 46), this specific type of chromosomal abnormality is classified as aneuploidy (specifically trisomy 21)
85. The Ethiopian Wolves are one of an endangered species which lose genetic diversity quickly because genetic drift is strong in such small populations. How the concept of genetic drift helps an ecologist? It is by [G12 Unit Four Evolution: Genetic drift 🖍]
A. designing breeding programs to maintain genetic variation in these species.
B. favoring an inbreeding program to reduce the genetic variation among them.
C. designing the way these species never interact with each other for years.
D. introducing an exotic species to the habitats of these wolves.
Answer: A
Explanation
Understanding genetic drift is essential for ecologists because it reveals how and why small, isolated populations (such as the ~500 remaining Ethiopian wolves) lose their genetic diversity.
🥕Because random chance events—like disease outbreaks or habitat fragmentation—disproportionately affect small populations, genetic drift can drastically reduce their ability to adapt to environmental changes over time.
86. A strong wind carried pollen from one flower population into another isolated population, introducing new alleles. Which evolutionary mechanism is illustrated? [ G12 Unit Four Evolution: Mechanism of Evolution 🖍]
A. Natural selection through competition
B. Genetic drift through random survival
C. Mutation through chromosome deletion
D. Gene flow through migration of genetic material
Answer: D
Explanation : Gene flow occurs whenever alleles are transferred from one population to another. | 164 |
| 16 | 77. For every single molecule of glucose processed in cellular respiration, that breakdown across three stages ( Glycolysis, Pyruvate Oxidation and Krebs cycle respectively) into the following energy-carrier counts that results
G12 Unit Three Energy Transformation : Cellular Respiration 🖍]
A. A. 2NADH 1NADH 6NADH and 1FADH2
B. 2NADH 2NADH and 2FADH2 6NADH
C. 2NADH 4NADH 6NADH and 6FADH2
D. 2NADH 2NADH 6NADH and 2FADH2
Answer: D
Explanation: Throughout cellular respiration, energy-carrier counts per single molecule of glucose break down as follows:
🥕Glycolysis: Produces 2 NADH.
🥕Pyruvate Oxidation: Converts the pyruvates into acetyl-CoA, producing 2 NADH (1 per pyruvate).
🥕Krebs Cycle (Citric Acid Cycle): Produces 6 NADH and 2 FADH₂ (3 NADH and 1 FADH₂ per acetyl-CoA).
78. Which of the following is the correct steps that shows the mechanism of electron transport system in mitochondria? G12 Unit Three Energy Transformation : Cellular Respiration 🖍]
A. It is the transfer of electrons from O2 to NADH or FADH2 by a series of specialized electron carrier proteins embedded in the inner mitochondrial membrane.
B. It is the transfer of electrons from NADH or FADH2 to O2 by a series of specialized electron carrier proteins embedded in the inner mitochondrial membrane.
C. It is the transfer of hydrogen from NADH or FADH2 to O2 by a series of specialized hydrogen carriers embedded in the outer mitochondrial membrane.
D. It is the transfer of NADH or FADH2 from one stages of respiration to the other stage through a series of specialized carrier molecules.
Answer: B
Explanation: The electron transport system (ETS) functions by transferring electrons from high-energy donors (NADH & FADH2 to a terminal electron acceptor (oxygen, O2. This occurs through a series of specialized protein complexes embedded specifically in the inner mitochondrial membrane
79. On which of the following aspects do Lamarck and Darwin’s theories of evolution agree? G12 Unit Four Evolution: Theory of evolution 🖍]
A. Evolution occurs by natural selection
B. Acquired traits are heritable
C. Speciation is the result of evolution.
D. New structures arise by use and dis use
Answer,: C
Explanation : Both Lamarck & Charles Darwin agreed that evolution is a real process driving organisms to adapt to their changing environments, which ultimately leads to the generation of new species. They primarily disagreed on the mechanisms behind these changes (Lamarck proposed the inheritance of acquired traits, whereas Darwin established natural selection).
80. Humans and horses share similar homologous structures which shows that they have been originated from a common ancestor and it is assumed that such organisms are closely related evolutionarily. Which evidence of evolution supports the above information? [G12 Unit Four Evolution: Evidence of evolution 🖍]
A. Comparative embryology
B. Comparative anatomy
C. Comparative physiology
D. Comparative biochemistry
Answer,: B
Explanation : Comparative anatomy involves studying the structural similarities and differences between different species. The presence of homologous structures (like the forelimbs of humans and horses) indicates divergent evolution and strongly points to a shared evolutionary origin
81. Which type of natural selection favours both extreme forms of a trait over the intermediate forms of a trait? G12 Unit Four Evolution: Process of evolution 🖍]
A. Random selection
B. Directional selection
C .Stabilizing selection
D. Disruptive selection
Answer: D
Explanation
Disruptive (or diversifying) selection actively favors both extreme forms of a trait over the average (intermediate) forms. This increases phenotypic variance and can eventually lead to speciation. | 207 |
| 17 | 70. Which of the following types of metabolism carried in living cells is an example of anabolic
process? [G12 Unit Three Energy Transformation : Photosynthesis 🖍]
A. Respiration
B. Glycolysis
C. Digestion of foods
D. photosynthesis
Answer: D
Anabolic processes (anabolism) use energy to build larger, complex molecules from smaller ones (e.g., plants using sunlight to build glucose).Catabolic processes (catabolism) break down large, complex molecules into smaller ones to release energy. Options A (Respiration), B (Glycolysis), and C (Digestion) are all catabolic processes.
71. Which of the following is the role of grana in the process of photosynthesis? G12 Unit Three Energy Transformation : Photosynthesis 🖍]
A. site of light independent reaction of photosynthesis.
B. possess chlorophyll used for light dependent reaction.
C. produce CO2 and consumes Oxygen.
D. site of carbon fixation and glucose production.
Answer: B
Explanation
Grana are stacks of disc-shaped structures called thylakoids found within the chloroplast. The membranes of these thylakoids contain chlorophyll, the pigment essential for absorbing light energy. Because they house this pigment and the necessary protein complexes (photosystems), grana serve as the specific site for the light-dependent reactions of photosynthesis.
72. Plants usually carry out the non-cyclic photophosphorylation but sometimes they also perform
cyclic photophosphorylation. They carry out the cyclic photophosphorylation when they need more : G12 Unit Three Energy Transformation : Photosynthesis 🖍]
A. ATP
B. NADPH
C. Both ATP and NADPH
D. Oxygen and water
Answer: A
Explanation
Cyclic photophosphorylation involves only Photosystem I (PSI). Electrons are recycled through the electron transport chain to generate a proton gradient that drives ATP synthesis but does not reduce NADP+ into NADPH.
73. During initial carbon fixation in the mesophyll cell of C4 plants, what are the CO2 acceptor and the first compound formed respectively? G12 Unit Three Energy Transformation : Photosynthesis 🖍]
A. Phosphoenol pyruvate and oxaloacetate
B. 1,5-ribulose bisphosphate and oxaloacetate
C. Oxaloacetate and 1,5-ribulose bisphosphate
D. Phosphoglycerate & oxaloacetate
Answer: C
Explanation : During the Synthesis stage of viral replication, the hijacked host cell metabolism is directed by the viral genome to transcribe viral mRNA, translate viral proteins, and replicate the viral DNA or RNA.
74. Which of the following is NOT the significance of photosynthesis? G12 Unit Three Energy Transformation : Photosynthesis 🖍]
A. it keeps the O2 and CO2 balance in the atmosphere
B. it produces the causes of global warming
C. it is the source of food for organisms
D. it produces oxygen for respiration.
Answer: B
Explanation Photosynthesis naturally removes carbon dioxide (a major greenhouse gas) from the atmosphere and releases oxygen, maintaining the balance of atmospheric gases and providing food and oxygen for living organisms
75. The whole processes of photosynthesis can be summarised by one of the following complete
equation. Identify it. G12 Unit Three Energy Transformation : Photosynthesis 🖍]
76. What are the net products we obtain at the end of glycolysis per glucose in our cells? G12 Unit Three Energy Transformation : Cellular Respiration 🖍]
A. 2 pyruvate, 2ATP and 2CO2
B. 2 pyruvate, 4ATP and 1NADH & 2H2O
C. 2 pyruvate, 2ATP and 2NADH and 2H2O
D. 2 pyruvate, 2ATP and 2NADH
Answer: C
Explanation: During glycolysis, one molecule of glucose is broken down into 2 molecules of pyruvate. While 4 ATP are actually made through substrate-level phosphorylation, 2 ATP are consumed during the initial energy-investment phase, yielding a net gain of 2 ATP. Additionally, 2 NADH and 2 H₂O molecules are produced. | 187 |
| 18 | 64. In the environmental biotechnology, genetically engineered mercury resistant bacteria metabolically breakdown toxic metallic mercury pollutant into a nontoxic compound. This environmental benefit is an application of microorganisms in
[ G11 Unit 4 Genetics Applied Genetics( genetic engineering, selective breeding in agriculture Bioinformatics,🖍]
A. bioremediation C. bioaccumulation
B. biosensors. D. bioinformatics
Answer: A
Explanation
Explanation: Bioremediation uses biological systems (like genetically engineered microorganisms) to detoxify or remove pollutants from the environment.
65. Gram-negative bacteria lose the crystal violet stain and take the color of the red counterstain to become red at the end of Gram's staining. The reason why they lose the crystal violet is [G12 Unit One Microorganisms- Bacteria 🖍]
A. they have no outer membrane made of lipopolysaccharide.
B. they have smaller body size than Gram positive bacteria.
C. their cell wall is composed of a thick layer of peptidoglycan.
D. their cell wall is composed of a thin layer of peptidoglycan.
Answer: D
Explanation
Gram-negative bacteria have a thin layer of peptidoglycan (often only one to three layers deep). During the decolorization step with alcohol or acetone, this thin layer is unable to retain the crystal violet-iodine complex, allowing it to be washed away.
66. Which of the following alternative contains all the general features of archaea? Archeans are:[ G12 Unit One Microorganisms- Bacteria 🖍]
A. prokaryotic, unicellular, and live as producers or decomposers.
B. prokaryotic, unicellular, and live only as decomposers.
C. prokaryotic, unicellular, and have true peptidoglycan in their cell walls.
D. eukaryotic, unicellular, and many are found in extreme environments.
Answer: A
Explanation : Prokaryotic: Members of the domain Archaea lack a defined nucleus and membrane-bound organelles.Unicellular: They are single-celled microscopic organisms.
🚩Producers or Decomposers: Archaeans exhibit diverse metabolic functions. Many species function as decomposers by breaking down organic matter.
🚩Others function as producers (such as chemosynthetic methanogens or photosynthetic halophiles) that fix carbon and supply energy to their unique ecosystems
67. Bedelle beer factory selected yeast instead of bacteria or molds for its beverage processing industry. Which reason best justifies this choice? G12 Unit One Microorganisms-🖍]
A. Rapid toxin production
B. Continuous acid secretion
C. Efficient sugar fermentation
D. Excessive moisture absorption
Answer: C
Explanation : Yeasts (specifically strains of Saccharomyces) are the foundational microorganism in brewing because they reliably and efficiently metabolize sugars extracted from malt into ethanol and carbon dioxide.
68. Which of the following disease caused by protozoan parasite affects white blood cells, skin & intestine and consequently results in skin ulceration and mucocutaneous complications? [G12 Unit Two Microorganisms Health & Economic Impacts( diseases caused by protozoan parasites🖍]
A. Leishmaniosis
B. African sleeping sickness
C. Malaria
D. Trichomoniasis
Answer, : A
Explanation
Leishmaniasis is a parasitic disease caused by protozoa of the genus Leishmania, which multiply inside the white blood cells of the host.
69. In the mechanism of viral replication that involves sequential events in five main stages, the viral DNA directs the cell’s metabolism to produce viral proteins and copies of phage DNA at the stage known as [G12 Unit Two Microorganisms : Viruses 🖍]
A. Release. C. Synthesis
B. Penetration. D. Adsorption
Asewer: C
Explanation : During the synthesis phase of the viral replication cycle, the viral genome takes over the host cell's metabolism. It redirects the cellular machinery to produce viral proteins and multiple copies of the phage's own DNA.Here is | 174 |
| 19 | 60. Why the effects of toxic bioaccumulation is more pronounced in those found at the top of food chain? Because [ G10 Unit Six Ecological Interactions 🖍]
A. organisms at the top of food chain are more resistant to toxic bio accumulates.
B. organisms at the top of food chain have more metabolic mechanism than others.
C. more toxic bio accumulates are needed by organisms at the top of food chain.
D. toxic bio accumulates are resistant to metabolism and stored along food chain.
Answer: D
Explanation
🥕Bioaccumulation: The buildup of a toxic substance over time within a single living organism. Because these chemicals are highly fat-soluble (lipophilic) and resistant to metabolic breakdown, they avoid being excreted and instead get stored directly into fatty (adipose) tissues.
🥕Biomagnification: The process by which the concentration of a toxicant multiplies progressively at each successive trophic level in a food web.
61. Unlike animals and plants, why do people classify gold, iron and fossil fuels as non-renewable natural resources? Because these non- renewable natural resources are [ G 11 Unit Six Environmental Biology Natural Resources 🖍]
A. finite resources and takes longer time to be produced
B. used for building and as an energy source
C. more important for human life than others
D. owned by developed countries.
Answer: A
Explanation
Non-renewable resources like gold, iron, and fossil fuels are classified this way because they exist in fixed, limited (finite) quantities within the Earth's crust. Unlike animals and plants, which can reproduce or grow within a human lifespan, these resources:
62. How the traditional alcoholic drinks such as tella are made by using microorganisms as starter culture? [G12 Unit One MOs:Industrial & Agricultural Importance🖍]
A. by mixing malt, yeast, rhamnus, roasted grain and stay for some days for fermentation.
B. by mixing water, malt, yeast, rhamnus, roasted grain and stay for some days for fermentation.
C. tella is made in a few minutes after mixing water, malt, yeast, rhamnus and roasted grain
D. tella is made a few years after mixing water, malt, yeast, rhamnus and roasted grain.
Answer: B
Explanation
Traditional Ethiopian alcoholic drinks like tella are brewed using a natural, wild fermentation process.
🥕The primary ingredients are water, malt (bikil), roasted grain (asharo / enkuro), and gesho (Rhamnus prinoides), which acts as a bittering and fermenting agent similar to hops in conventional beer.
♦️The mixture is left to ferment over several days.
🥕Microorganisms like Saccharomyces (yeast) and Lactobacillus (lactic acid bacteria) naturally present in the ingredients and traditional clay pots convert the sugars into alcohol and acids to produce the characteristic flavor.
63. Genetically modified maize plants are protected against an attack by insect pest known as the corn borer. Such agricultural biotechnological application is explained as [ G11 Unit 4 Genetics Applied Genetics( genetic engineering, selective breeding in agriculture,🖍]
A. development of insect resistant crops
B. the use of viruses to kill crop pests
C. the use bio pesticide method
D. the use of glyphosate resistant gene
Answer: A
Explanation
Genetically modified (GM) maize—commonly known as Bt corn—contains an inserted gene from the soil bacterium Bacillus thuringiensis (Bt). This gene allows the plant to produce a specific protein that is toxic to certain pests like the corn borer. Because the plant itself can naturally ward off the insect without external chemicals, this biotechnological application is classified as developing insect-resistant crops. | 166 |
| 20 | 55. Which of the following health effects of substance use is mostly related to Khat? [G11 Unit Five The Human Body Systems : Respiratory System 🖍]
A. J-shaped legs, colorectal cancer, cirrhosis and dementia.
B. Hypertension, stomatitis, esophagitis, gastritis & constipation
C. Harms the brain, breathing system, heart and child development.
D. Sleepiness and confusion
Answer: B
Explanation
Khat chewing is widely documented to cause these gastrointestinal and cardiovascular issues. The astringent tannins in the leaves contribute to mouth sores (stomatitis), inflammation of the esophagus (esophagitis), stomach irritation (gastritis), and constipation.
56. Mark recapture method is mostly used to study population density of which organism? [G11 Unit Six Population Ecology 🖍]
A. Birds. C. Human
B. Plants. D. Slow moving animals
Answer: D
Explanation
The mark-recapture method is an indirect technique primarily used to estimate the population density of mobile, secretive, or highly motile animals (such as mammals, birds, or fish). However, it is most reliable and mainly applied to organisms that are sufficiently mobile to mix well into the population, but slow-moving enough to be safely caught, marked, and recaptured within the study period
57. Which one of the following is true about logistic population growth model? G11 Unit Six Population Ecology 🖍]
A. Growth model with “J” shaped curve.
B. Unlimited resource in the environment.
C. Growth levels off at carrying capacity.
D. Growth without environmental constraints.
Answer: C
ExplanationIn a logistic growth model, population growth is limited by the environment's carrying capacity (K), which is the maximum population size an environment can sustain. As the population size (N) approaches this limit, resources become scarce, and the growth rate decreases until it levels off at (K).
58. Which one of the following condition can be an example of density dependent population regulation mechanism? [G11 Unit Six Population Ecology 🖍]
A. A drought that reduces water availability for all organisms.
B. A change in climatic condition that affecting all species equally.
C. An earth quake that destroys habitats without regard to population size.
D. A disease outbreak that spreads rapidly through a crowded city.
Answer: D
Explanation
Density-Dependent Factors: These are factors whose effects on the size or growth of the population vary with the population density. In a crowded city, a disease spreads much faster and affects a larger percentage of the population than it would in a sparsely populated area.
🚩Other examples include resource competition, predation, and parasitism.
🚩 Option A , B and C are an example of Density-Independent Factors/regulations
🥕Density-dependent factors include competition, predation, and disease,
🥕while density-independent factors include natural disasters, climate, and pollution.
59. Which indigenous knowledge of Ethiopian farmers is used to conserve soil and control pests and weeds? [ G10 Unit Six Ecological Interactions 🖍]
A. Contour ploughing
B. Surface mulching
C. Mixed cropping
D. Crop rotation
Answer: D
Explanation : Crop rotation is a cornerstone agronomic practice used by smallholder farmers across Ethiopia to restore and maintain soil fertility while simultaneously breaking the cycles of weeds, pests, and specific crop diseases.
🥕By alternating major cereals (like wheat, teff, or maize) with legumes (like faba beans or chickpeas), farmers naturally improve soil nitrogen, control pest infestations, and suppress weed growth. | 179 |
