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Grade 12 Biology national exam, 2006 E.C. (2014 G.C.)
93 questions · 120 minutes. The first 5 answers are shown with explanations; sit the whole paper timed in the app to get your score and the textbook page behind every question.
- 1.Which of the following do viruses share with cells?
- A. Cell wall
- B. Cytoplasma
- C. Nucleic acid
- D. Protoplasma
Answer: C. Viruses and cells both contain nucleic acid, which carries genetic information. A virus has either DNA or RNA, while cells also have nucleic acid. Viruses do not have a cell wall, cytoplasm, or protoplasm. Textbook: Grade 10, unit 3 · section 3.1.3. - 2.Which one of the following cellular forms did Robert Hooke observe under his crude microscope?
- A. Bacteria
- B. Protozoa
- C. Yeast
- D. Empty cell wall
Answer: D. The key idea is what Hooke saw when he examined cork. He saw empty cell walls, which looked like small boxes. A is wrong because bacteria were not what Hooke observed; B is wrong because he did not observe protozoa; C is wrong because he did not observe yeast. Textbook: Grade 9, unit 3 · section 3.6. - 3.In the case of enzymatic chemical reactions, what do you call the substance that is acted up on by an enzyme?
- A. Polypeptide
- B. Coenzyme
- C. Vitamin
- D. Substrate
Answer: D. The substance an enzyme acts on is called its substrate. The enzyme acts on the substrate during a chemical reaction. A polypeptide is a chain of amino acids, not the name for the substance acted on. A coenzyme helps some enzymes work, and a vitamin is a nutrient that may be used to make a coenzyme. Textbook: Grade 11, unit 3 · section 3.2.1. - 4.Choose the organisms that belong to the eukaryotes?
- A. Bacteria
- B. Blue -green algae
- C. Amoeba
- D. Virus
Answer: C. The question tests which organism has eukaryotic cells, cells with a nucleus. Amoeba is a eukaryote, so C is correct. A and B are prokaryotes, which lack a nucleus; D is a virus and is not made of cells. Textbook: Grade 12, unit 2 · section 2.11. - 5.While conducting research, which of the following should a biologist do first?
- A. Generate a hypothesis
- B. Conduct experiment
- C. Communicate the results
- D. Identify a research question / problem
Answer: D. The key idea is that research begins by deciding what problem to study. A biologist first identifies a research question or problem. A hypothesis is made after the question; an experiment tests an idea; results are communicated after the study. - 6.Which of the following structures is NOT present in animal cells?
- A. Cell wall
- B. Nucleus
- C. Protoplasm
- D. Nucleic acid
Answer, explanation and textbook page: open in the app. - 7.An experimental animal stopped responding to a stimulus that has been repeated so many times .What type of learned behavior is this ?
- A. Latent learning
- B. Habituation
- C. Imprinting
- D. Operant conditioning
Answer, explanation and textbook page: open in the app. - 8.Behavior that is repeated on a daily basis is referred to as:
- A. Lunar
- B. Circadian
- C. Circannua
- D. Seasonal
Answer, explanation and textbook page: open in the app. - 9.Which molecule in the cell is the constituent of the gene?
- A. Nucleic acid
- B. Protein
- C. Lipid
- D. Carbohydrate
Answer, explanation and textbook page: open in the app. - 10.Which is the branch of biology that studies abut the origin and gradual changes of living things?
- A. Microbiology
- B. Evolution
- C. Mutation
- D. Reproduction
Answer, explanation and textbook page: open in the app. - 11.What is the general term for the part of the protoplasms that lies outside the nucleus?
- A. Cytosol
- B. Cytoplasm
- C. Central vacuole
- D. Plasma membrane
Answer, explanation and textbook page: open in the app. - 12.How many net ATP molecule are generated through anaerobic respiration , when a single glucose molecule is change to pyruvate in the human body?
- A. Tow
- B. Three
- C. Four
- D. Six
Answer, explanation and textbook page: open in the app. - 13.Which of the following groups of bacteria consists of rod shaped cells?
- A. Gram - positive
- B. Bacilli
- C. Cocci
- D. Spirilla
Answer, explanation and textbook page: open in the app. - 14.How many carbon and oxygen tomes are there in a molecule of maltose?
- A. 6 carbon and 6 oxygen
- B. 12 Carbone and 11
- C. 11 carbon and 12 oxygen
- D. 24 carbon and 12 oxygen
Answer, explanation and textbook page: open in the app. - 15.On which of the following organelles of the eukaryotic cell does protein synthesis take place?
- A. The nucleus
- B. The ribosome
- C. The chloroplast
- D. The mitochondrion
Answer, explanation and textbook page: open in the app. - 16.Which of the following parts of plant roots is harboring nitrogen fixing bacteria
- A. Root nodule
- B. Root hair
- C. Root tip
- D. Root cap
Answer, explanation and textbook page: open in the app. - 17.Which of the following is true about protozoa?
- A. They are a group of bacteria
- B. They are one-celled organisms
- C. They represent both plant and animals
- D. They are unicellular animals
Answer, explanation and textbook page: open in the app. - 18.Which of the following is a distinguishing feature of amino acids that is NOT found in carbohydrates?
- A. Carbon
- B. Oxygen
- C. Hydrogen
- D. Nitrogen
Answer, explanation and textbook page: open in the app. - 19.Which of the following statement is true about matter and energy in the ecosystem?
- A. Both matter and energy are recycled
- B. Matter is not recycled energy is recycled
- C. Matter is recycled energy is not recycled
- D. Energy is recycled more than matter does
Answer, explanation and textbook page: open in the app. - 20.Which one of the following molecule in living things is not an organic molecule?
- A. Sugar
- B. Nucleotide
- C. Amino acid
- D. Water
Answer, explanation and textbook page: open in the app. - 21.At which stage is most of the ATP generated in aerobic respiration?
- A. Glycolysis
- B. Link reaction
- C. Krebs cycle
- D. Electron transport
Answer, explanation and textbook page: open in the app. - 22.Which of the following is the common characteristic of all enzymes?
- A. They act inside cells only
- B. They are proteins PH
- C. They require cofactors
- D. They operate at any
Answer, explanation and textbook page: open in the app. - 23.In a cross between round green pea of RRyy genotype wrinkled yellow pea of rrYY genotype, what is the expected genotype of the F1?
- A. RRyy
- B. rrYY
- C. RRYY
- D. RrYy
Answer, explanation and textbook page: open in the app. - 24.Which of the following cellular structures is possessed by all cells
- A. Cell membrane
- B. Nucleus
- C. Cell wall
- D. Golgi apparatus
Answer, explanation and textbook page: open in the app. - 25.During the krebs cycle which of the following molecule temporarily stores most of the energy released from food molecule
- A. ADP
- B. ATP
- C. NADH
- D. FADH
Answer, explanation and textbook page: open in the app. - 26.Which of the following carbohydrate has structural function?
- A. Cellulose
- B. Glycogen
- C. Starch
- D. Sucrose
Answer, explanation and textbook page: open in the app. - 27.Which of the following forms of nitrogen are readily utilization by green plants?
- A. Atmospheric nitrogen
- B. Nitrite
- C. Ammonium ion
- D. Nitrate
Answer, explanation and textbook page: open in the app. - 28.In some crosses of maize, the progeny produces better yield than the parents. What is this phenomenon known as?
- A. Dominance
- B. Hetrozygosity
- C. Hybrid vigor
- D. Inbreeding depression
Answer, explanation and textbook page: open in the app. - 29.Which of the following techniques is used to separate DNA fragments according to their size on gel?
- A. Southern blotting
- B. Electrophoresis
- C. Radioactive labeling
- D. Digestion by restriction
Answer, explanation and textbook page: open in the app. - 30.Which of the following group of animals have males with ZZ and females with ZW sex chromosome constitution?
- A. Grasshopper
- B. Birds
- C. Mammals
- D. Honey bee
Answer, explanation and textbook page: open in the app. - 31.The molecule of which pigment is located at the reaction center of a photosystem?
- A. Chlorophyll a
- B. Chlorophyll b
- C. Carotenoid
- D. Accessory pigments
Answer, explanation and textbook page: open in the app. - 32.According to Lamarck's theory of evolution what is the mechanism by which evolving organisms acquire new structures?
- A. Mutation
- B. Hereditary variation
- C. Use -and- disuse of parts of the body
- D. Recombination of ancestral genes
Answer, explanation and textbook page: open in the app. - 33.In which of the activities of the honey bee colony are worker bees involved?
- A. Laying eggs
- B. Serving as queens
- C. Reproductive function
- D. Taking care of the larvae
Answer, explanation and textbook page: open in the app. - 34.In which one of the following ways the Tundra biome differs from desert biome?
- A. It is a treeless biome
- B. It has little biodiversity
- C. It receives little precipitation
- D. It has permanently frozen subsoil
Answer, explanation and textbook page: open in the app. - 35.Which one of the following is the mechanism by which tow genes located on the same chromosome are separated?
- A. Independent assortment
- B. Segregation
- C. Linkage
- D. Crossing over
Answer, explanation and textbook page: open in the app. - 36.If present in the fermentation system which one of the following would negatively affect alcohol production by yeasts?
- A. Water
- B. Oxygen
- C. Glucose
- D. Fermentation enzyme
Answer, explanation and textbook page: open in the app. - 37.Which of the following mechanism moves digested amino acids and glucose across the plasma membrane of the cell lining the wall of the small intestine?
- A. Osmosis
- B. Simple diffusion
- C. Facilitated diffusion
- D. Active transport
Answer, explanation and textbook page: open in the app. - 38.Where exactly in the cell dose the Krebs cycle take place?
- A. Mitochondrial matrix
- B. Inner mitochondrial membrane
- C. Cytoplasmic fluid
- D. Outer mitochondrial membrane
Answer, explanation and textbook page: open in the app. - 39.What is the ultimate source of renege for all organism living on the earth?
- A. Water
- B. Oxygen
- C. Nitrogen
- D. The sun
Answer, explanation and textbook page: open in the app. - 40.Which of the following substance is NOT necessary for photosyntheseis to take place?
- A. Chlorophyll
- B. Carbon dioxide
- C. Oxygen
- D. Water
Answer, explanation and textbook page: open in the app. - 41.Which group of organic compound includes the enzymes?
- A. Proteins
- B. Lipids
- C. Starches
- D. Carbohydrates
Answer, explanation and textbook page: open in the app. - 42.Into which of the following organic compound can lipase maltase and sucrase be grouped?
- A. Hormones
- B. Carbohydrates
- C. Nucleic acids
- D. Enzymes
Answer, explanation and textbook page: open in the app. - 43.Choose the characteristics that viruses share with living things.
- A. They are made up of many specialized cells
- B. They contain genetic material
- C. They reproduce by mitosis
- D. They contain chlorphyll
Answer, explanation and textbook page: open in the app. - 44.Which one of the following eukaryotic cell organelles was a free living cell before eukaryotic cells evolved?
- A. Nucleus
- B. Ribosome
- C. Chloroplast
- D. Nucleolus
Answer, explanation and textbook page: open in the app. - 45.If radioactive substance that weighs one kilogram has a half-life of 100 years what would be the percentage of the substance left after 300 years?
- A. 50
- B. 30
- C. 25
- D. 12.5
Answer, explanation and textbook page: open in the app. - 46.Which of the following PH values represents the strongest base?
- A. 2
- B. 7
- C. 13
- D. 15
Answer, explanation and textbook page: open in the app. - 47.In Ethiopia, which one of the following vertebrate groups has the largest number of genera?
- A. Mammals
- B. Birds
- C. Reptiles
- D. Amphibians
Answer, explanation and textbook page: open in the app. - 48.Which of the following is an accurate representation of the relationships between the terms metabolism anabolism and catabolism?
- A. Anabolism = Catabolism
- B. Metabolism =Catabolism
- C. Anabolism = Catabolism + Metabolism
- D. Metabolism = cataboilsm + Anabolism
Answer, explanation and textbook page: open in the app. - 49.Which do you call structures that have the have the same evolutionary origin but now are different in structure or have different functions?
- A. Endemic
- B. Analogous
- C. Homologous
- D. Indigenous
Answer, explanation and textbook page: open in the app. - 50.Which term describes the process by which water is lost by evaporating through the stomata of leaves ?
- A. Transport
- B. Transpiration
- C. Anchorage
- D. Adhesion
Answer, explanation and textbook page: open in the app. - 51.Which of the following is true about saturated fatty acids?
- A. They have single bonds between carbon atoms
- B. They are the same as polyunsaturated fatty acids
- C. They are the same as monounsaturated fatty acids
- D. They have double bonds between the carbon atoms
Answer, explanation and textbook page: open in the app. - 52.For a biological detergent to effectively remove oily and greasy dirt, which of the following enzymes should it contain?
- A. Cellulase
- B. Protease
- C. Amylase
- D. Lipase
Answer, explanation and textbook page: open in the app. - 53.In which kingdom of life is it most likely to finde many examples of organisms that can undergo metamorphosis?
- A. Monera
- B. Fungi
- C. Plantae
- D. Animals
Answer, explanation and textbook page: open in the app. - 54.During protein synthesis where in the cell does transcription take place?
- A. Ribosome
- B. Nucleus
- C. Endoplasmic reticulum
- D. Golgi apparatus
Answer, explanation and textbook page: open in the app. - 55.What is a perfect flower?
- A. A flower with petals and pistil
- B. A flower with stamens and sepals
- C. A flower with stamens and pistil
- D. A flower with sepals and petals
Answer, explanation and textbook page: open in the app. - 56.Which molecules carry the instruction for protein synthesis?
- A. Carbohydrates and lipids
- B. Amino acids
- C. DNA and RNA
- D. Enzymes
Answer, explanation and textbook page: open in the app. - 57.Which of the following resources is needed by an ecosystem from outside in order to sustain itself
- A. Producers
- B. Macronutrients
- C. Micronutrients
- D. Sunlight
Answer, explanation and textbook page: open in the app. - 58.Which of the following is true about the substance represented by the chemical formula ?
- A. Simple sugar
- B. Inorganic substance
- C. Fatty acid
- D. Amino acid
Answer, explanation and textbook page: open in the app. - 59.Which one of the following characteristic is UNNECESSARY for an object to be considered a living thing?
- A. Ability to respond to stimuli
- B. Ability to reproduce
- C. Ability to grow
- D. Ability to move
Answer, explanation and textbook page: open in the app. - 60.Which filed studies the way in which individual traits of organisms are transmitted from one generation to the next?
- A. Genetics
- B. Ecology
- C. Evolution
- D. Morphology
Answer, explanation and textbook page: open in the app. - 61.In which of the following ways is the carbon dioxide of the atmosphere fixed in to the Carbone found in organic molecules?
- A. In the breathing processes of all animals
- B. In the decomposition of organic molecules
- C. In the process of photosynthesis by green plants
- D. In all the cellular respiration processes of organisms
Answer, explanation and textbook page: open in the app. - 62.Which of the following is NOT a term used to describe organisms that have had foreign genes added to them?
- A. Genetically modified organisms
- B. Transgenic organisms
- C. Genetically engineered organisms
- D. Pathogenic organisms
Answer, explanation and textbook page: open in the app. - 63.Which of the following is prevented from taking place if populations are separated by a geographic barrier?
- A. Mutation
- B. Evolution
- C. Gene flow
- D. Natural selection
Answer, explanation and textbook page: open in the app. - 64.In protein synthesis, what is produced during transcription?
- A. Protein
- B. mRNA
- C. DNA
- D. Polypeptide
Answer, explanation and textbook page: open in the app. - 65.If a cell fails to clear its cellular debris which one of its organelle is most likely NOT functioning?
- A. Nucleus
- B. Mitochondria
- C. Endoplasmic reticulum
- D. Ribosomes
Answer, explanation and textbook page: open in the app. - 66.Which of the following applies to the tropical rainforest?
- A. Low rainfall and hight temperature
- B. Low rainfall and low temperature
- C. High rainfall and hight temperature
- D. High rainfall and low temperature
Answer, explanation and textbook page: open in the app. - 67.Which stage in the life cycle of HIV is inhibited by the antiretroviral drug known as integrase ᓼ inhibitor?
- A. conversion of viral RNA to DNA
- B. Replication of the viral genome
- C. Insertion of the viral genome in to host genome
- D. Release of the viral progeny from the cell
Answer, explanation and textbook page: open in the app. - 68.Which of the following groups of plants carry out light dependent and light independent reaction of photosynthesis in separate cells?
- A. C-3 plants
- B. C-4 plants
- C. CAM plants
- D. plants with out chlorophyll
Answer, explanation and textbook page: open in the app. - 69.Among the following identify the organelle in which nucleic acid is NOT found ?
- A. Mitochondria
- B. Chloroplast
- C. Ribosome
- D. Golgi apparatus
Answer, explanation and textbook page: open in the app. - 70.The half-life of carbon-14 is about 5730 years. If a fossil is 17200 years old, about what percent of its original carbon -14 is still present in the fossil?
- A. 75 %
- B. 50 %
- C. 25 %
- D. 12 %
Answer, explanation and textbook page: open in the app. - 71.Which of the following pairs of individuals have identical DNA fingerprints?
- A. Father and sun
- B. Mother and daughter
- C. Brother and sister
- D. Monozygotic twins
Answer, explanation and textbook page: open in the app. - 72.Among the following which one has little or no contribution to the loss of biodiversity?
- A. Overgrazing by domestic animals
- B. Clearing forests to grow crops
- C. Growing crops of improved verities
- D. Growing crops of land
Answer, explanation and textbook page: open in the app. - 73.Suppose sites A,B,C and D have Simpson's Index of Diversity (d) values of 20,8,16,and 3, respectively, which site is dominated by one or just a few species?
- A. Site A
- B. Site B
- C. Site C
- D. Site D
Answer, explanation and textbook page: open in the app. - 74.Which of the following types of chromosome mutations gives rise to an extra chromosome?
- A. Inversion
- B. Trans location
- C. Deletion
- D. Non- disjunction
Answer, explanation and textbook page: open in the app. - 75.Suppose a hypothetical cube- shaped cell has sides of 10 micrometers, what is the surface area to volume ratio of this cell?
- A. 6:10
- B. 10:10
- C. 3:6
- D. 4:8
Answer, explanation and textbook page: open in the app. - 76.which of the following pairs are analogous structures ?
- A. Wing of bird and wing of a butterfly
- B. Front leg of a horse and a human arm
- C. Wing of a bird and wing of a bat
- D. Front leg of a frog and wing of a bat
Answer, explanation and textbook page: open in the app. - 77.How are unsaturated fats distinguished?
- A. They are made up of glucose and fructose
- B. They are made up of amino acids and glycerol
- C. They have double bonds in their carbon chains
- D. They have only single bonds at the points of attachment
Answer, explanation and textbook page: open in the app. - 78.Which of the the following mating produces children all having the same ABO blood phenotypes
- A. AO x AB
- B. BB x OO
- C. AO x BO
- D. AA x BO
Answer, explanation and textbook page: open in the app. - 79.During aerobic respiration what is the route through which protons return from the mitochondrial inter-membrane space back to its matrix?
- A. Proton pump
- B. ATP synthase
- C. Ion channel
- D. Membrane lipid
Answer, explanation and textbook page: open in the app. - 80.From which of the processes of cellular respiration is the majority of the ATP generated?
- A. Anaerobic fermentation
- B. Glycolysis and link reaction
- C. Electron transport and chemiosmosis
- D. Krebs cycle and glycolysis
Answer, explanation and textbook page: open in the app. - 81.Choose the one that represent a chemical formula of an organic compound?
- A. $\mathrm{C_{12}H_{22}O_{11}}$
- B. $\mathrm{Mg(OH)_2}$
- C. $\mathrm{NH_3}$
- D. $\mathrm{NaCL}$
Answer, explanation and textbook page: open in the app. - 82.In which of the following solutions does an animal cell undergo hemolysis?
- A. In hypotonic solution
- B. In hypertonic solution
- C. In isotonic solution
- D. In both hypotonic and hypertonic solution
Answer, explanation and textbook page: open in the app. - 83.What does the absence of chloroplast in a unicellular organism indicate?
- A. Reproduction by sexual means
- B. Autotrophic ᓼnutrition
- C. Heterotrophic nutrition
- D. Completed lack of metabolic processes
Answer, explanation and textbook page: open in the app. - 84.Which of the following did the early heterotrophs do that probably assisted the origin of autotrophs?
- A. They added oxygen and chlorophyll to the environment
- B. They added carbon dioxide to the environment
- C. They stored energy in the bonds of inorganic compound
- D. They manufactured food from carbon dioxide and oxygen
Answer, explanation and textbook page: open in the app. - 85.If DNA contain 10% thymine, what is the percentage of cytosine in the DNA?
- A. 10%
- B. 30%
- C. 40%
- D. 90%
Answer, explanation and textbook page: open in the app. - 86.Which of the following conclusions can be drawn the structural similarities observed between the flippers of whales and the arms of humans?
- A. The human species began life in the ocean
- B. The human species and whales share a common ancestry
- C. Whales are older than the human species
- D. Whales have evolved from early humans that went back to the ocean
Answer, explanation and textbook page: open in the app. - 87.Which of the following will happen if a plant cell is kept in a solution that is stronger than its protoplasms?
- A. The cell will become turgid
- B. The central vacuole will expand
- C. The protoplasms will get plasmolysed
- D. The cell will swell and burst
Answer, explanation and textbook page: open in the app. - 88.Which of the following is produced when a lipid molecule is hydrolyzed?
- A. Amino acid and water
- B. Amino acid and glucose
- C. Fatty acids and glycerol
- D. Glucose and glycerol
Answer, explanation and textbook page: open in the app. - 89.What is the ecological succession in which plant communities establish after an area has been completely demolished by fire?
- A. Tree succession
- B. Secondary succession
- C. Primary succession
- D. Bare rock succession
Answer, explanation and textbook page: open in the app. - 90.What is the difference between HIV and AIDS?
- A. AIDS is the virus and HIV is the disease
- B. Both AIDS and HIV refer to the disease
- C. AIDS is the disease and HIV is the virus
- D. Both AIDS and HIV refer to the virus
Answer, explanation and textbook page: open in the app. - 91.From which organism is the first antibiotic used in medicine produced ?
- A. Gram negative bacteria
- B. Members of the fungi
- C. Genetically modified protozoa
- D. Higher plants
Answer, explanation and textbook page: open in the app. - 92.Biotechnology can be applied in environmental remediation . To which of the major application areas of biotechnology is this most related?
- A. Medicine and nutrition
- B. Medicine and industry
- C. Biodiversity and industry
- D. Agriculture and environment
Answer, explanation and textbook page: open in the app. - 93.Suppose in an experiment conducted to test a new drug, 20 people were given the drug and 20 people a placebo. What is the control of the experiment?
- A. People who received the placebo
- B. People who received the new drug
- C. The new drug itself
- D. The new drug and the placebo
Answer, explanation and textbook page: open in the app.