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Biology
Question | Answer |
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How do scientists begin work? What must they do before experimentation? | Scientific thinking usually begins with obserations, then they gather info from the observations called data (quantitive: numbers, qualitative: pictures). They then make an inference (an explanation based on prior knowledge) and a hypothesis. |
What is a controlled experiment? What does it allow the scientist to isolate and test? | An experiment where only one variable is changed at a time. All other variables are unchanged, or controlled. This allows the scientist to test his/her hypothesis. |
What is a well-tested explanation that unifies a broad range of observations? | A theory. |
What are the characteristics of living things? | They're made up of cells, reproduce, based on a universal genetic code, grow and develop, obtain and use materials and energy, respond to their environment, maintain a stable environment, change over time (as a group). |
What is cell specialization? Why is it important in multicellular organisms? | Cells that are diverse; each type of cell performs a specialized function. Cells must be diverse in multicellular organisms so that they can perform different functions. |
What is the process by which organisms keep their internal conditions fairly constant? | Homostasis. |
What is the term for the land, water, and air on Earth? | Biosphere. (or ecosystem?) |
What is the term for a group of organisms of one type living in the same place? | A population. |
What are the various levels of organization? | Biosphere, ecosystem, community, population, organism, group of cells (organs, tissues, etc.), cells, molecules. |
What is a compound? What is a solution? | Compound: a substance formed by the chem. combo of 2 or more elements in definite proportions. Solution: a mixture of 2 or more substances where the molecules of the substances are evenly distributed. |
What makes up a molecule of water? | H2O; 2 hydrogen and 1 oxygen. |
Why does ice float on water? | Water expands as it freezes, so ice is less dense than liquid water, making it float. |
What is the most abundant compound in most living things? | Water. |
Why are water molecules polar? | There is an uneven distribution of electrons between the oxygen and hydrogen atoms because of a water molecule's bent shape. |
What are acids and bases? What does pH measure? | Acids: any compound that produces H+ ions in solution. Bases: any compound that produces OH- ions (hydroxide). The pH scale measures the concentration of hydrogen ions. |
A substance with a pH of 4 would be what? | An acid. |
Describe monosaccharides and polysaccharides. | Monosaccharides: single sugar molecules. Polysaccharides: large macromolecules formed from monosaccharides. |
Which of the organic compounds is the main source of energy for living things? | Carbohydrates. |
What is a chemical reactions? | A process that changes or transforms one set of chemicals into another. Mass and energy are conserved during chemical transformations. |
Identify the reactant(s) in a chemical reaction. | Reactants are the elements or compounds that enter a chemical reaction. |
What is the term used to describe the energy needed to get a reaction started? | Activation energy. |
What are catalysts? | A substance that speeds up the rate of a chemical reaction. |
How do enzymes affect the reactions in living cells? | Enzymes speed up chemical reactions that take place in cells by lowering the activation energy. |
What is the the combined portions of Earth in which all living things exist? | The biosphere. |
All of the members of a particular species that live in one area are called a(an) _______. | A population. |
What is a producer? What is a consumer? | Producer: Autotrophs (organisms that capture energy from sunlight or chemicals to make their own food). Consumer: Heterotrophs (organisms that rely on feeding on other organisms for their energy). |
What is the original source of almost all the energy in most ecosystems? | Sunlight. |
What is an organism called that uses energy to produce its own food supply from inorganic compounds? | Autotroph. |
What is an organism called that cannot make its own food? | Heterotroph. |
Organisms that obtain nutrients by breaking down dead and decaying plants and animals are called what? | Detritivores. |
What is an organism that feeds only on plants called? | Herbivore. |
What is the total amount of living tissue within a given trophic level called? | Biomass. |
What is an ecological model of the relationships that form a network of complex interactions among organisms in a community from producers to decomposers? | Food web. |
What are the animals called that eat both producers and consumers? | Omnivores. |
What is the term for each step in the transfer of energy and matter within a food web? | Trophic level. |
A cat stalks, kills, and then eats a bird. Based on its behavior, which ecological terms describe the cat? | Heterotroph, carnivore. |
What is most of the energy available to a consumer trophic level used for? | Only 10% of the energy is transferred to the next consumer. The rest is used by the organism or released into the environment as heat. |
Which type of pyramid shows the amount of living tissue at each trophic level in an ecosystem? | Biomass pyramid. |
Why can matter recycle through the biosphere? | Biological systems don't use up matter; they transform it. It's assembled as living tissue or passed out of the body as waste. |
What is the repeated movement of water between Earth’s surface and the atmosphere called? | Evaporation. |
What does NOT recycle in the biosphere? | Energy. |
What is the process called by which bacteria convert nitrogen gas in the air to ammonia? | Nitrogen fixation. |
What are ways that carbon is stored in the biosphere? | Biological processes (photosynthesis, respiration, decomposition), geochemical processes (erosion, volcanic activity), mixed biogeochemical processes (burial and decomposition of dead organisms converting into fossil fuels), and human activities. |
Which organisms have a direct role in the nitrogen cycle? | Bacteria (legumes). |
Why do organisms need nutrients? | To build tissues and carry out essential life functions. |
How are the movements of energy and nutrients through living systems different? | Energy flows one way. |
What's the importance of biogeochemical cycling? | Elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another through biogeochemical cycles. |
What is climate? | The average year-after-year conditions of temps. and precipitation in a particular region. |
What is the greenhouse effect? | The natural situation where heat is retained by a layer of greenhouse gases. |
Effect of Earth's three main climate zones. | Polar zones: cold areas where the sun's rays strike at a low angle. Temperate zones: between polar and tropical zones, ranges from hot to cold depending on the season Tropical zones: near equator, most directly hit with sunlight. |
What is an abiotic factor? | Physical, nonliving factors that shape an ecosystem (temp., wind, nutrient availability). |
What is a biotic factor? | The biological influences on organisms within an ecosystem (birds, trees, bacteria, etc.). |
What is an organism’s niche? | The full range of physical and biological conditions in which an organism lives and the way it uses those conditions. |
What is predation? | An interaction where one organism captures and feeds on another. |
A symbiotic relationship in which both species benefit is called? | Mutualism. (Commensalism: one species benefits, one's not harmed/helped. Parasitism: one species helped, one harmed). |
The series of predictable changes that occurs in a community over time is called what? | Ecological succession. |
What is the difference between primary and secondary succession? | Primary: a succession on land that occurs where no soil exists (on surfaces of ash after an eruption or on rocks after glaciers melt). Secondary: a succession that occurs after a disturbance (after a wildfire, earthquake). |
Which is a factor that could interrupt the progress of succession? | Climate change, human activities. |
Climate conditions in a small area that differ significantly from the climate of the surrounding area are called what? | Microclimate. |
What is population density? | The number of individuals per unit area. |
What is the movement of organisms into a given area from another area called? | Immigration. |
What is emigration? | The movement of individuals out of an area. |
Explain what must occur in a population for it to grow. | More births, less deaths, more immigrations. |
Explain what is happening in a population as it decreases. | More deaths than births, emigration. |
What happens to a population when resources become less available? | There would be more deaths, leading to a decline in population. |
In a logistic growth curve, exponential growth is the phase in which the population does what? | Grow/reproduce at a constant rate. A logistic growth also has a stop after the exponential curve. |
If a population grows larger than the carrying capacity of the environment what happens? | The growth stops around the carrying capacity. |
What are density-independent limiting factors? | They are factors that affect all populations in similar ways, regardless of the population. |
What density-dependent factors other than the predator/prey relationship affected the populations of moose and wolves on Isle Royale? | There could've been parasitism or diseases. |
What does a diagram of a population’s age structure show? What predictions can be made? | It shows the population of a country broken down by gender and age group. You can predict the population in the future. |
How is energy is released from ATP? | By breaking the chemical bond between the second and third phosphates. |
Ingenhousz showed that plants produce what? Where does most of the mass of a plant come from? | Plants can transform CO2 and water into carbohydrates and also release oxygen in the presence of light. Most of the mass is from CO2, H2O, and carbohydrates. |
Photosynthesis uses sunlight to convert water and carbon dioxide into what materials? | High-energy sugars and 6 oxygen. |
What materials are used in the overall reactions for photosynthesis? | 6 Water, 6 CO2, light, chlorophyll. |
How do plants take in the sun’s energy? | Pigments like chlorophyll absorb it. |
Why do most plants appear green? | The chlorophyll doesn't absorb the sunlight well in the green region of the spectrum, so green light is reflected by the leaves. |
What is a granum? | A stack of thylakoids embedded in the stroma of a chloroplast. |
The Calvin cycle is also known as what type of reaction? Why? | A light-independent reaction, because it does not require light. |
What is a product of the Calvin cycle? | High energy sugars. |
What would happen if carbon dioxide is completely removed from a plant’s environment? What would you expect to happen to the plant’s production of high-energy sugars? | Because the Calvin cycle requires CO2, it won't work, and therefore it won't produce any high-energy sugars. |
What conditions affects the rate of photosynthesis? | Shortage of water, temperature, and intensity of light. |
What are the stages of cellular respiration? | Glycolysis -> Krebs cycle -> Electron transport chain. |
What is released during cellular respiration? | 6 CO2, 6 H2O, energy. |
What is the equation for cellular respiration? | 6 O2 + C6H12O6 -> 6 CO2 + 6 H2O + Energy. |
What is the starting molecule for glycolysis? | Glucose. |
What acts as an electron carrier in cellular respiration? | NAD+ |
Lactic acid fermentation occurs where? | In your muscles during rapid exercise when your body can't supply enough oxygen. |
Explain alcoholic fermentation. | It is anaerobic (a process that doesn't require oxygen) and happens to certain microorganisms like yeast after glycolysis. The reactants are pyruvic acid and NADH; the products are ethyl alcohol, CO2, and NAD+. |
If oxygen is present, glycolysis is followed by what step? | The Krebs cycle. |
Why is cellular respiration is called an aerobic process? | It's a process that requires oxygen. |
The energy of the electrons passing along the electron transport chain is used to make what? | To convert ADP into ATP. |
When the body needs to exercise for longer than 90 seconds, it generates ATP by carrying out what process? | Cellular respiration. |
Explain how cellular respiration and photosynthesis are almost opposite processes. | Photosynthesis: "deposits" energy, captures energy, takes place in the chloroplast, produces C6H12O6 + O2 CR: "withdraws" energy, releases energy, takes place in mitochondria. produces CO2 + H2O. |
How are the products of photosynthesis used in cellular respiration? | O2: helps release energy from food. C6H12O6: the food. |
How does science differ from other disciplines, such as history and the arts? | Scientists continue to question and it's a way of knowing rather than an unchanging knowledge. |