WorksheetsGeneral Biology 2 – 3rd Periodical Examination (Grade 11)
Total questions: 60
Worksheet time: 3615secs
Which pathway for aerobic cellular respiration is located in the cytoplasm of the cell?
Glycolysis
Krebs cycle
Electron transport system
Link reaction
What are the reactants involved in cellular respiration?
C6H12O6 and H2O
O2 and H2O
C6H12O6 and O2
CO2 and C6H12O6
Which pathway will result in the production of four carbon dioxide molecules, two ATP molecules, NADH2 and FADH2?
Glycolysis
Link reaction
Krebs cycle
Electron transport system
Which of the following describes the process of chemiosmosis?
The movement of hydrogen atoms across a mitochondrial membrane.
The movement of hydrogen ions across a mitochondrial membrane.
The movement of electrons across the cell membrane.
The movement of glucose through the cell membrane.
In recombinant DNA technology, what molecule is the most commonly used DNA vector (or carrier, used to insert foreign genetic material into an organism’s genome)?
Gene
Plasmid
Cell
Protein
What technique pertains to creating an organism that is an exact genetic copy of the other organism?
artificial selection
cloning
gene splicing
gel electrophoresis
Recombinant DNA technology involves using enzymes and various laboratory techniques to manipulate and isolate DNA segments of interest. All are products of rDNA technology EXCEPT _______.
Golden rice
Macapuno
Bt corn
Insulin
What type of organism was the first to be successfully modified via the techniques of genetic engineering?
mouse
bacteria
virus
plant
The primitive lobe-finned fish shown below is thought to be an ancestor of early amphibians. This evolutionary development from fish to amphibian is believed to have occurred during the ______.
Triassic period
Devonian period
Tertiary period
Permian period
About 200 million years ago, all the continents on Earth were actually one huge "supercontinent" surrounded by one enormous ocean. This gigantic continent, called Pangaea. During which period does the supercontinent Pangaea start to separate into Laurasia and Gondwanaland?
Permian period
Triassic period
Jurassic period
Cretaceous period
Which of the represents the longest time period?
Cenozoic
Mesozoic
Paleozoic
Precambrian
As per the latest radiometric dating, what is the age of the Earth?
3 billion years
3.6 billion years
4 billion years
4.6 billion years
Which of the following is the correct sequence of time frame from oldest to youngest?
Cenozoic, Paleozoic, Mesozoic, Precambrian
Mesozoic, Paleozoic, Cenozoic, Precambrian
Precambrian, Paleozoic, Mesozoic, Cenozoic
Paleozoic, Mesozoic, Precambrian, Cenozoic
An alteration in the arrangement of nucleotides in a chromosome possibly resulted in either a structural or physiological change in the organism. What mechanism of evolution behind this change?
Genetic drift
Gene flow
Mutation
Natural selection
Which of the following occurs when migrating individuals interbreed with a new population?
Genetic drift
Gene flow
Mutation
Natural selection
What mechanism of evolution occurs when a small group of individuals leaves a population and establishes a new one in a geographically isolated region?
Genetic drift
Gene flow
Mutation
Natural selection
Which of the following statements correctly describes the artificial selection?
The environment controls which organisms will survive.
Humans determine which organisms will survive.
The extremes of the population have a lesser chance to survive.
The extremes of the population have a better chance to survive.
The hind leg bones shown in the whale in the figure at the right are examples of ______.
homologous structures
analogous structures
fossil structures
vestigial structures
What type of evolution that occurs when organisms adapt to live in a common environment and take on the look of each other, but do not evolve from a common ancestor?
Adaptive Radiation
Convergent Evolution
Natural Selection
Oscillating Selection
DNA of the life forms on Earth is almost universal and seems to be template from one original source. This line of inferring can be based from what evidence of evolution?
Embryology
fossil record
molecular biology
comparative anatomy
Anaerobic respiration is carried out in the _____ and leads to the production of _______.
absence of oxygen, 2 ATP molecules
presence of oxygen, 2 ATP molecules
absence of oxygen, 36 ATP molecules
presence of oxygen, 36 ATP molecules
Of the following metabolic processes, which one is common to photosynthesis and cellular respiration?
Reactions that convert light energy to chemical energy.
Reactions that split H2O molecules and release O2.
Reactions that store energy by pumping H+ across membranes.
Reactions that convert CO2 to sugar.
All of these are performed to produce recombinant DNA EXCEPT _______.
Removal of the genetic sequences of an organism.
Selection of the perfect vector with which the gene has to be integrated.
Insertion of the genetic sequences into other sequences of another organism.
Selection of the perfect enzymes with which the gene has to be integrated.
Why genetic engineering is considered more precise than classical breeding?
It relies on chance combinations of genes through mating.
It does not involve any changes in the DNA sequence.
It takes multiple generations to introduce a new trait.
It allows scientists to target and modify specific genes.
The Precambrian Time makes up most of Earth's history and saw the formation of the planet. Why is this time significant?
A human civilization started in this period.
It marks the first evidence of life on Earth.
It was a time of stable climate and little change.
At this time, Dinosaurs roamed and dominated the planet.
The Paleozoic Era saw multiple evolutionary milestones, including the appearance of vertebrates, plants, and land animals. Which of the following is NOT a characteristic of the Paleozoic Era?
The first land plants appeared.
Mammals dominated the land.
The first insects evolved.
Amphibians and reptiles emerged.
The first reptiles evolved during the Carboniferous Period, giving them an advantage over amphibians. Why were reptiles able to survive better in drier environments?
They had a more efficient respiratory system than amphibians.
Their tough skin and specialized eggs reduced water loss.
They grew larger and became dominant predators.
Their ability to blend into surroundings kept them safe from predators.
During the Jurassic Period, dinosaurs became the dominant land animals, and early birds started to appear. What allowed dinosaurs to thrive during this period?
The expansion of warm, tropical forests and abundant food sources.
The complete absence of predators and competition.
The sudden cooling of Earth's climate, favoring reptilian adaptations.
The isolation of dinosaurs on small islands, preventing them from competing with other animals.
In the context of evolutionary biology, which of the following scenarios best illustrates the concept of artificial selection?
The development of resistance in mosquitoes to insecticides due to repeated exposure.
The variation in beak size among finches on different Galapagos Islands in response to environmental differences.
The breeding of maize (corn) by indigenous peoples from a wild grass species to produce larger, more nutritious kernels.
The adaptation of bacteria to survive extreme conditions, such as high temperatures or acidic environments.
Gene flow can occur when individuals from one population move to a new area and interbreed with individuals from a different population. Which of the following is an example of gene flow?
A population of frogs in one pond becoming genetically distinct from frogs in another pond due to isolation.
A group of wolves migrating from one forest to another and mating with the local population.
A species of flower developing resistance to drought in response to climate change.
An individual bird acquiring a new trait from a mutation.
The eye of the octopus and the eye of the cat show different patterns of structure, yet they perform a similar function. This is an example of:
Homologous organs that have evolved due to divergent evolution.
Analogous organs that have evolved due to convergent evolution.
Analogous organs that have evolved due to divergent evolution.
Homologous organs that have evolved due to convergent evolution.
Fox and polar bears which are distant relatives both developed white colored fur to adapt to the snowy environment where they live. These body structures are identified as:
Homologous structures
embryonic structures
analogous structures
vestigial structures
Preserved remains of a cave-dwelling man from cold and icy places suggest that humans look different in the past. What evidence of evolution is used?
Embryology
fossil record
molecular biology
comparative anatomy
Which is NOT true about fossils?
They suggest that life has a history.
They are proofs of life in the past.
The older the fossil, the less it looks like modern day species.
They seem precisely like modern-day species, regardless of their age.
During cellular respiration, oxygen is required for the final step of aerobic respiration. If a cell is placed in an environment without oxygen, what would most likely happen during glucose metabolism?
The cell will continue producing ATP through aerobic respiration by relying on alternative electron acceptors.
The cell will use anaerobic respiration or fermentation to generate ATP, although the energy yield will be lower.
The cell will rely on anaerobic processes, but will stop ATP production altogether due to the lack of oxygen.
The cell will prioritize the breakdown of fats instead of glucose to generate ATP, bypassing glycolysis.
During intense physical activity, the body requires more energy and oxygen to support muscle function. Which of the following occurs when the body cannot supply enough oxygen to muscles during exercise?
Aerobic respiration takes over to produce more ATP.
Anaerobic respiration occurs, leading to the production of lactic acid.
The electron transport chain becomes more efficient at low oxygen levels.
Oxygen is stored in the muscles to increase energy output.
Recombinant DNA technology enables the transfer of genes between species to produce organisms with desired characteristics. Which of the following would be considered a potential risk of using recombinant DNA technology in agriculture?
The transferred genes may lead to unintended consequences, such as new allergens or toxins in the food supply.
Recombinant DNA technology reduces the overall genetic diversity of crops, making them more susceptible to diseases.
The crops developed through recombinant DNA technology will always outcompete natural varieties, leading to extinction of native species.
The use of recombinant DNA technology in agriculture leads to crops that are less resistant to environmental factors such as drought.
The Golden Rice project uses recombinant DNA technology to introduce genes that produce beta-carotene into rice. What is the primary benefit of Golden Rice for populations in areas with high rates of malnutrition?
Golden Rice supports immune system function and helps protect against infections, particularly in children and pregnant women.
Golden Rice contributes to improved eyesight, particularly in low-light conditions, and reduces the risk of night blindness.
Golden Rice helps in maintaining healthy skin and cell growth, improving overall health in communities with limited access to a diverse diet.
Golden Rice aids in enhancing bone health, preventing conditions related to calcium deficiency in populations with poor diet diversity.
During the Cambrian Period of the Paleozoic Era, there was a significant increase in the diversity of life forms. Which factor most likely contributed to the "Cambrian Explosion" of biodiversity?
The widespread appearance of land plants that provided new habitats for marine life.
The development of vertebrates, which outcompeted invertebrates for food and territory.
The rise in atmospheric oxygen levels, allowing for complex organisms to evolve.
The shift from a warm climate to an ice age, which forced organisms to adapt quickly.
The Pliocene Epoch of the Cenozoic Era saw significant climatic changes as Earth cooled. Which of the following was a likely impact of the cooling climate during the Pliocene on terrestrial ecosystems?
It caused the expansion of deserts, leading to the adaptation of new species of drought-resistant plants and animals.
It resulted in the widespread development of temperate grasslands and the evolution of large herbivores.
It led to the extinction of many species of large mammals, such as mastodons and mammoths that could not adapt to cooler conditions.
It led to the widespread formation of tropical rainforests, providing a new habitat for many species of reptiles.
In anaerobic conditions, fermentation provides an alternative pathway to produce ATP when oxygen is not available for the electron transport chain. Which of the following best explains why fermentation is less efficient than aerobic respiration in terms of ATP production?
Fermentation bypasses the citric acid cycle and electron transport chain, resulting in the loss of potential energy from glucose.
Fermentation produces more pyruvate than aerobic respiration, but fewer ATP molecules are generated per glucose molecule.
Fermentation produces ATP through oxidative phosphorylation, but without oxygen, the energy yield is reduced.
Fermentation converts glucose into more complex molecules, which require more ATP to break down.
In yeast cells, when oxygen is scarce, they switch to alcoholic fermentation to produce energy. Which of the following would most likely occur if a yeast cell were placed in a sealed container without oxygen for an extended period?
The yeast would produce lactic acid through fermentation, leading to a buildup of lactic acid in the cells.
The yeast would undergo aerobic respiration, as the cell would quickly adapt to the lack of oxygen.
The yeast would shift to alcoholic fermentation, producing ethanol and carbon dioxide as byproducts.
The yeast would cease ATP production and enter a dormant state due to the absence of oxygen.
The process of aerobic respiration is more energy-efficient than fermentation. Based on this, which of the following situations would make the most sense for an organism to use fermentation instead of aerobic respiration?
An organism is in an environment with abundant oxygen and needs to produce large quantities of ATP.
An organism is in an oxygen-deprived environment and needs to continue producing ATP, even though less efficiently.
An organism prefers to metabolize glucose more slowly, even when oxygen is present, to avoid oxidative stress.
An organism has sufficient mitochondrial ATP production but needs to conserve glucose for other metabolic processes.
In an experimental setup, cells are exposed to a drug that blocks the electron transport chain, preventing oxidative phosphorylation. Which of the following is the most likely outcome of this drug’s action on the cells’ ability to produce ATP?
The cells will rely entirely on fermentation to produce ATP, which will be less efficient than aerobic respiration.
The cells will continue aerobic respiration, but without the electron transport chain, ATP production will be unaffected.
The cells will shift to fatty acid oxidation as the primary pathway to produce ATP, bypassing glucose metabolism entirely.
The cells will increase glycolysis to compensate for the blocked electron transport chain, leading to an overall increase in ATP production.
The creation of Bt cotton involved inserting a gene from the bacterium Bacillus thuringiensis that produces a toxin harmful to certain pests. In evaluating the impact of Bt cotton on the local ecosystem, which of the following potential consequences would be most important to consider?
The gene from Bacillus thuringiensis might be transferred to wild plants, creating genetically modified weeds that are resistant to pests.
The toxin produced by Bt cotton may harm beneficial insects, such as pollinators or non-target species, disrupting the local food web.
The introduction of Bt cotton could result in the elimination of all pests in the region, creating an ideal environment for crop production.
The presence of Bt cotton will reduce the need for water and nutrients, improving the efficiency of agricultural practices.
In a controlled experiment, a scientist introduces a gene from a fish that allows the plant to withstand freezing temperatures. Which of the following is the best approach for evaluating the success of this genetic modification?
Comparing the growth rate of the genetically modified plant to that of a non-modified plant under normal temperature conditions.
Exposing both the genetically modified and non-modified plants to freezing temperatures and comparing their survival rates.
Analyzing the gene expression of the fish gene in the plant’s genome to determine whether it was successfully incorporated.
Monitoring the plant’s yield in a controlled greenhouse environment to determine the economic benefits of the genetic modification.
During the Devonian Period, which is often referred to as the "Age of Fishes," fish diversity saw major advancements. When evaluating the significance of the Devonian in the evolution of vertebrates, which of the following is the most likely explanation for the rise of early amphibians?
The appearance of shallow freshwater environments that offered abundant food sources for fish to evolve into amphibians.
The evolution of air-breathing structures in fish, which enabled them to move from aquatic to terrestrial environments.
The increase in atmospheric carbon dioxide, which allowed for more abundant plant life and supported the development of herbivorous amphibians.
The development of complex ecosystems in oceans that provided fish with evolutionary pressure to adapt to land environments.
The Hadean Eon, the earliest period of Earth's history, was characterized by extreme heat and volcanic activity. When evaluating the conditions that led to the formation of Earth's early atmosphere, which of the following factors would be most relevant?
The cooling of Earth's surface, which led to the formation of oceans that stabilized atmospheric gases.
The collision of Earth with comets, which delivered significant amounts of water and oxygen to the planet’s surface.
The release of gases from volcanic eruptions that formed the primary components of Earth's early atmosphere, including water vapor and carbon dioxide.
The gradual formation of tectonic plates, which helped create a more stable atmosphere over time.
In a population of rabbits, some individuals have longer fur while others have shorter fur. A cold winter causes a decrease in food availability, making the longer-furred rabbits more likely to survive. Over time, the frequency of longer fur in the population increases. Which mechanism is primarily responsible for this change?
Mutation, as new genetic variations appeared that favored longer fur.
Gene flow, as individuals with longer fur migrated into the population.
Natural selection, as longer fur provided an adaptive advantage in the cold climate.
Genetic drift, due to the random death of individuals with shorter fur.
A breeder intentionally selects certain dogs with desirable traits, such as large size or a specific coat color, to produce the next generation. Over several generations, the frequency of these traits increases. Which mechanism is being applied in this scenario?
Genetic drift, through random selection of traits.
Natural selection, where only the best-adapted dogs are allowed to reproduce.
Artificial selection, where humans deliberately choose certain traits to enhance.
Mutation, where genetic changes lead to the desired traits.
A population of beetles is exposed to a new environment with a different set of plants for food. Some beetles have mutations that allow them to eat these new plants. These beetles are more likely to survive and reproduce. What mechanism of evolution is responsible for the increase in the new trait over generations?
Natural selection, as the mutated beetles are better adapted to the new food source.
Mutation, as the change in the trait occurred by chance.
Genetic drift, as random changes in beetle traits led to the new trait becoming common.
Gene flow, as beetles from a neighboring population introduced the mutation.
A population of wolves shows a variety of coat colors. Some wolves are isolated due to a river separating the population. Over time, the coat colors of the wolves on either side of the river become distinct from one another. Which evolutionary mechanism is most responsible for this change?
Gene flow, as genetic material moved between the two populations.
Natural selection, as the different environments led to different survival pressures on coat color.
Mutation, causing random changes in coat color on both sides of the river.
Genetic drift, as random changes in allele frequencies resulted from the separation.
A scientist observes that in a population of fish, the frequency of a gene for body color changes dramatically after a few individuals from a nearby population join the group. This introduces a new allele for body color into the gene pool. Which evolutionary mechanism best explains this change?
Natural selection, as the new allele provided a survival advantage.
Mutation, as a random genetic change led to the new body color.
Gene flow, as the introduction of new individuals caused a shift in the gene pool.
Genetic drift, as the new allele spread by chance after a small number of individuals joined the population.
In a population of lizards, a random genetic change occurs that results in some individuals having an unusual body color. This trait neither provides a survival advantage nor a disadvantage. How did this color variation arise?
Genetic drift, as the color change spread randomly due to small population size.
Mutation, as a random genetic alteration caused the new body color.
Natural selection, as the new color helped the lizards blend with the environment.
Gene flow, as the new color was introduced from a neighboring lizard population.
A population of flowers consists of both red and yellow individuals. After a wildfire, the only flowers left are yellow. Over time, the population consists exclusively of yellow flowers. What is the most likely explanation for this change?
Gene flow, as yellow flowers from other areas joined the population.
Natural selection, as yellow flowers survived the fire better than red flowers.
Genetic drift, where the random event (the fire) reduced the number of red flowers.
Mutation, as a genetic change caused the population to become yellow.
A biologist is investigating a new organism that can survive both with and without oxygen. She hypothesizes that the organism performs a specific type of cellular respiration when oxygen is absent. Which of the following metabolic pathways would the organism likely use to produce ATP in the absence of oxygen?
Glycolysis followed by the Krebs cycle, and the electron transport chain for anaerobic respiration.
Alcoholic fermentation in the cytoplasm, producing ethanol and CO2.
Lactic acid fermentation in the mitochondria, producing lactic acid.
Glycolysis followed by lactate production, and a small amount of ATP produced by substrate-level phosphorylation.
A scientist is studying the efficiency of aerobic respiration in a cell. She blocks the process at a certain step and measures the ATP produced. Which of the following steps, if blocked, would most directly decrease ATP production during aerobic respiration?
Glycolysis, because it produces two molecules of NADH and ATP.
The Krebs cycle, because it generates high-energy electron carriers like NADH and FADH2.
The electron transport chain, as it creates a proton gradient used for ATP synthesis.
Alcoholic fermentation, because it allows NADH to be recycled in the absence of oxygen.
You have been asked to design a microorganism that can efficiently switch between aerobic respiration and fermentation depending on the oxygen concentration. How could you modify the microorganism to balance energy production between both pathways?
Increase the efficiency of the electron transport chain to produce more ATP in aerobic conditions, while also modifying the organism to rely on lactic acid fermentation when oxygen is absent.
Enhance glycolysis to ensure more glucose is converted to pyruvate, and allows the pyruvate to be fermented into ethanol or lactate under anaerobic conditions.
Optimize the Krebs cycle to generate more NADH and FADH2, which are needed for ATP production in aerobic conditions, while also reducing the efficiency of fermentation pathways.
Engineer the organism to use only alcoholic fermentation regardless of oxygen availability, maximizing ethanol production for biofuel purposes.
You are tasked with designing a new microorganism that can efficiently produce ATP under aerobic conditions. You need to ensure the microorganism utilizes all three stages of aerobic respiration to maximize energy yield. Which of the following modifications would you make to the organism’s metabolic pathways?
Increase the efficiency of glycolysis by boosting the rate of glucose breakdown, ensuring the production of more pyruvate for the subsequent Krebs cycle.
Enhance the Krebs cycle by introducing additional enzymes that allow for faster conversion of pyruvate into citric acid and more NADH and FADH2 for the electron transport chain.
Modify the electron transport chain to introduce more electron carriers, increasing ATP production by optimizing the flow of electrons and proton gradient formation.
Engineer the organism to use glycolysis and the Krebs cycle, but bypass the electron transport chain, using the resulting intermediates for other cellular functions.
A team of researchers were given the task of developing a new organism that will be used in bioengineering to generate ATP for a variety of applications. Given that aerobic respiration involves glycolysis, the Krebs cycle, and the electron transport chain, what is the best approach to maximize the organism’s ATP production under aerobic conditions?
Optimize the glycolysis pathway to maximize the breakdown of glucose into pyruvate, while minimizing the activity of the Krebs cycle and electron transport chain.
Enhance the Krebs cycle to produce more electron carriers (NADH and FADH2), ensuring the electron transport chain is highly active and ATP is generated efficiently.
Alter the electron transport chain by adding additional electron carriers to increase the ATP output during oxidative phosphorylation.
Focus on optimizing glycolysis for rapid energy production, without involving the Krebs cycle or electron transport chain, limiting the efficiency of ATP production.
