Science Methodology and Experiments

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Questions and Answers

What is the primary result of excessive nutrients in water bodies?

Algae bloom (correct)

Enhanced photosynthesis

Increased oxygen levels

Decreased fish population

During which part of photosynthesis is oxygen produced?

Calvin Cycle

Decomposition Reactions

Light-Independent Reactions

Light-Dependent Reactions (correct)

What do decomposing bacteria primarily consume in water after an algae bloom?

Glucose

Dead algae (correct)

Light energy

Carbon dioxide

What is produced as a direct result of the light-dependent reactions of photosynthesis?

NADPH Signup and view all the answers

Where do the light-independent reactions of photosynthesis, also known as the Calvin Cycle, occur?

In the stroma of chloroplasts Signup and view all the answers

What is the role of the independent variable in a controlled experiment?

It is the factor that is manipulated by the scientist. Signup and view all the answers

Which characteristic is NOT shared by all living things?

Ability to fly. Signup and view all the answers

What type of data is represented by the height of grass measured in centimeters?

Quantitative data. Signup and view all the answers

What is a scientific theory?

A tested explanation of natural events that unifies many observations. Signup and view all the answers

Which subatomic particle is positively charged?

Proton. Signup and view all the answers

Which of the following is a method of reproduction that does NOT involve sex?

Asexual reproduction. Signup and view all the answers

Valence electrons are important because they determine:

How an atom will react in chemical reactions. Signup and view all the answers

Which of the following best describes homeostasis?

Maintenance of a stable internal environment. Signup and view all the answers

What characterizes isotopes of an element?

They have the same atomic number but different atomic masses. Signup and view all the answers

What type of bond forms when electrons are shared between atoms?

Covalent Bond Signup and view all the answers

Which property of water is responsible for allowing lightweight objects to float on its surface?

Cohesion Signup and view all the answers

What is the primary function of carbohydrates in living organisms?

Energy source and structural support Signup and view all the answers

Which of the following macromolecules is primarily composed of nucleotides?

Nucleic Acids Signup and view all the answers

What process breaks down larger molecules into smaller units?

Hydrolysis Reaction Signup and view all the answers

Which factor can affect the activity of an enzyme?

Temperature and pH Signup and view all the answers

What is the role of enzymes in chemical reactions?

Lower the activation energy Signup and view all the answers

What describes an exothermic reaction?

It releases energy as heat. Signup and view all the answers

What is carbon's bonding capacity based on its valence electrons?

4 Signup and view all the answers

What type of bond is formed between sodium and chlorine in a salt compound?

Ionic Bond Signup and view all the answers

Which of the following describes the polarity of water?

Water is polar with uneven charge distribution. Signup and view all the answers

What is the result when table salt dissolves in water?

Salt dissociates into sodium and chloride ions. Signup and view all the answers

Which factor does NOT affect climate?

Longitude Signup and view all the answers

What is a significant threat to the tropical rain forest biome?

Deforestation Signup and view all the answers

What type of forest is characterized by trees that shed their leaves?

Temperate Deciduous Forest Signup and view all the answers

Which biome has a climate characterized by long, dark winters and short, cool summers?

Tundra Signup and view all the answers

What is the primary vegetation type in a savanna biome?

Grasses Signup and view all the answers

Which aquatic factor influences the distribution of organisms in freshwater ecosystems?

Salinity Signup and view all the answers

What type of soil is typically found in a temperate grassland?

Fertile and rich Signup and view all the answers

In which freshwater biome would you most likely find trout and minnows?

Stream Signup and view all the answers

What adaptation is common among animals in the taiga biome?

Hibernate or migrate Signup and view all the answers

Which layer of a lake typically has the highest temperature?

Euphotic layer Signup and view all the answers

What is a common characteristic of a desert biome?

Low humidity Signup and view all the answers

Which characteristic of temperate rain forests is NOT accurate?

Sparse plant growth Signup and view all the answers

Which adaptation helps desert plants conserve water?

Waxy coating Signup and view all the answers

What is likely to be a primary factor influencing currents in aquatic environments?

Wind patterns Signup and view all the answers

Which of the following best defines climate?

Long-term patterns of temperature and precipitation Signup and view all the answers

What process describes how heat energy is trapped in the atmosphere?

The Greenhouse Effect Signup and view all the answers

Which factor primarily determines the occurrence of different biomes?

Temperature and precipitation Signup and view all the answers

Which phenomenon is most likely to cause wetter and warmer weather on the eastern Pacific compared to the western Pacific?

El Niño-Southern Oscillation (ENSO) Signup and view all the answers

What is the primary reason hot air rises?

It is less dense than cold air Signup and view all the answers

Which type of wind travels from east to west in the tropics?

Trade Winds Signup and view all the answers

What happens to rising air that carries moisture as it ascends?

It cools, causing condensation Signup and view all the answers

What defines a population in ecological terms?

Groups of organisms of the same species in a specific area Signup and view all the answers

Which of the following statements is true regarding the Coriolis Effect?

It affects wind patterns due to Earth's rotation Signup and view all the answers

What leads to the creation of high pressure areas on Earth’s surface?

Sinking cold air Signup and view all the answers

Which statement accurately describes upwelling?

Cold bottom water rises to the surface Signup and view all the answers

What is the result of human activities, particularly burning fossil fuels, on climate?

They cause changes in long-term climate patterns Signup and view all the answers

Which of the following elements is NOT considered a greenhouse gas?

Oxygen Signup and view all the answers

What type of vegetation is primarily found in marshes?

Mostly herbaceous, shade-intolerant vegetation Signup and view all the answers

Which of the following wetlands is known for peat-forming characteristics?

Fens Signup and view all the answers

What is a defining feature of salt marshes?

Dominance of salt-tolerant grasses Signup and view all the answers

What is the process of photosynthesis primarily used by?

Herbaceous plants and algae Signup and view all the answers

Which of the following processes describes energy transfer in an ecosystem?

Only a small portion of energy is available to organisms at the next level Signup and view all the answers

What is the largest reservoir in the water cycle?

The ocean Signup and view all the answers

In the nitrogen cycle, what is nitrogen fixation?

Conversion of nitrogen gas into ammonia Signup and view all the answers

What impact does excessive use of fertilizers have on aquatic systems?

Promotes eutrophication of water bodies Signup and view all the answers

What is the primary role of decomposers in an ecosystem?

Chemically break down organic matter Signup and view all the answers

What is the main process by which coral reefs contribute to marine ecosystems?

Providing habitat and nursery areas Signup and view all the answers

Which statement is true about the biomass pyramid?

It illustrates the relative amount of living organic matter Signup and view all the answers

Which group of organisms primarily utilizes chemosynthesis?

Bacteria in hydrothermal vents Signup and view all the answers

What is the main difference between fens and bogs?

Fens are alkaline and bogs are often acidic Signup and view all the answers

Which of the following is NOT a component of the phosphorus cycle?

Respiration of animals Signup and view all the answers

Study Notes

Science

Science answers questions based on observation, research, investigation, and measurement.
Science uses evidence to create testable explanations and predictions of natural events.
Scientific methodology is a general style of investigation, not a strict process.
Observation involves noticing and describing events orderly.
Inference is a logical interpretation based on existing knowledge.
Hypotheses are tentative explanations that can be tested.
Scientific theories are tested explanations unifying many observations.

Controlled Experiments

Variables are factors that change.
Independent variable is the factor changed by the scientist..
Dependent variable is the factor that changes in response to the independent variable.
Control group lacks the independent variable.
Controlled variables/constants are factors kept the same.

Collecting Data

Quantitative data is measured with numbers.
Qualitative data is descriptive.

Peer Analysis and Feedback

Publication of scientific papers stimulates further research and questions.
Peer review maintains credibility in scientific findings.

Characteristics of Living Things

Living things are composed of cells.
Reproduction occurs through sexual (between male and female) or asexual (single organism) reproduction.
Living things share a universal genetic code.
Growth and development occur.
Response to stimuli (e.g., light, temperature) happens.
Homeostasis (stable internal environment) is maintained.
Living things evolve over time.
Are viruses alive? No. They lack the characteristics of living things, such as cellular structure and independent metabolism. They do not grow, reproduce independently, or maintain homeostasis.

Atoms & Compounds

Atoms consist of protons (positive, in the nucleus), neutrons (neutral, in the nucleus), and electrons (negative, orbiting the nucleus).
Valence electrons determine atomic behavior in chemical reactions.
An element is a pure substance of one type of atom.
Atomic number is the number of protons in an atom (e.g., carbon's atomic number is 6).
Isotopes of an element have the same number of protons but different numbers of neutrons (some isotopes are radioactive).
A chemical compound is formed from the combination of two or more elements.

Types of Chemical Bonds

Ionic bonds are formed when electrons are transferred. (e.g., Na loses an electron to Cl)
Covalent bonds are formed when atoms share electrons. (e.g., H₂O)
Van der Waals forces are weak attractions between molecules.

Determining Bonding Capacity

Bonding capacity is related to the number of valence electrons. (e.g., carbon has 4 valence electrons and can form 4 bonds)

Water

Water (H₂O) is composed of two hydrogen atoms and one oxygen atom.
Water molecules are polar (uneven charge distribution). Oxygen is partially negative, hydrogens positive
Hydrogen bonds occur between partially positive hydrogen atoms and partially negative oxygen atoms.
Cohesion is the attraction between molecules of the same substance (e.g., water molecules).
Cohesion causes surface tension that allows lightweight objects to float on water.
Adhesion is the attraction between molecules of different substances (e.g., water adhering to glass).
Meniscus is the curved surface of water in a container.

Properties of Water

High heat capacity: Water resists temperature change, regulating aquatic environments
Excellent solvent: Water dissolves many ionic and polar molecules. (e.g. NaCl in water).

Carbon & Macromolecules

Carbon is central to biological molecules, forming complex organic compounds.
Macromolecules are large molecules (polymers) formed by smaller organic molecules (monomers).
Carbohydrates (C, H, O, 1:2:1 ratio) - Function: energy source and structural support - Monomer: monosaccharide - Polymer: polysaccharide - Examples: glucose, sucrose, glycogen, starch, cellulose
Lipids (C, H, some O) - Function: long-term energy storage - Monomer: fatty acids and glycerol - Polymer: triglycerides - Examples: fats, oils, waxes, steroids (saturated vs unsaturated)
Nucleic Acids (C, H, O, N, P) - Function: store and transmit genetic information - Monomer: nucleotide - Polymer: nucleic acid - Examples: DNA, RNA
Proteins (C, H, O, N) - Function: structural support, transport, signaling, speeding up reactions - Monomer: Amino acid - Polymer: protein - Examples: hemoglobin
Enzymes catalyze reactions, lowering activation energy

Condensation & Hydrolysis Reaction

Condensation: joins monomers to form polymers
Hydrolysis: breaks down polymers into monomers

Enzymes

Chemical Reactions: Atoms rearrange, forming new substances.
Chemical Equations: Formulas and arrows show reactants and products (e.g., respiration and photosynthesis).
Activation Energy: Minimum energy needed for a reaction.
Exothermic Reactions: Release energy.
Endothermic Reactions: Absorb energy.
Enzymes: Special proteins lower activation energy
Enzymes are not altered in a reaction
Enzymes are specific to a particular reaction.
Substrates are the reactants binding to the active site.
Temperature and pH affect enzyme activity.
Denaturation is the loss of an enzyme's shape and function (due to extreme conditions).

Climate and Weather

Weather: Short-term atmospheric conditions.
Climate: Long-term patterns of temperature and precipitation.
Greenhouse Effect: Trapping heat in the atmosphere by greenhouse gases (CO2, water vapor, methane).
Seasons: Caused by Earth's tilted axis as it orbits the Sun.

Atmospheric Cells, Wind, and Rain

Convection: Hot air rises, cool air sinks.
Coriolis Effect: Earth's rotation deflects air movement.
Surface Winds: (trade winds, westerlies, polar easterlies)
Precipitation: More likely in low-pressure areas.
Mountains: Shape rainfall patterns.
Climate Change: Changes in weather patterns, caused by human activities.
Ocean Currents: Driven by winds, temperature, salinity, and Earth's rotation.
Upwelling: Brings nutrients to the surface.
El Niño/La Niña: Climate patterns in the Pacific Ocean affecting weather globally.

Biosphere

Organisms/species: Individuated living things.
Populations: Groups of same species in an area.
Communities: Groups of interacting species.
Ecosystems: Include organisms and their environment.
Biosphere: The entire living Earth.
Biotic factors: Living components (plants, animals, etc.)
Abiotic factors: Non-living components (air, water, etc.)
Biomes: Major communities based on climate.

Biome Characteristics

Determined by climate (temperature and precipitation)
Climatograph: graphs that show climate variables
Biome classifications influenced by latitude and altitude.
Temperate rainforest, temperate deciduous forest, taiga, temperate grassland, tropical seasonal, savanna, chaparral, desert, tundra
Aquatic Biomes: freshwater (streams, rivers, lakes, ponds, wetlands) and saltwater (intertidal, coastal, open ocean)

Food Webs

Producers: use sunlight or chemicals to make food
- Photosynthesis converts CO2 and H2O to carbohydrates and oxygen.
- Chemosynthesis utilizes chemical energy for carbohydrate production.
Consumers: rely on other organisms for energy
- Herbivores feed on plants
- Carnivores eat other animals
- Omnivores consume plants and animals
- Scavengers feed on dead animals
- Detritivores eat decomposing matter
- Decomposers break down organic material
Food webs show interconnected food chains.
Energy and biomass decrease at higher trophic levels.
Solar energy is the initial source of energy for most ecosystems.

Nutrient Cycles

Water Cycle: Evaporation, transpiration, condensation, precipitation, runoff, seepage.
Carbon Cycle: Photosynthesis, respiration, deforestation, combustion, fossil fuels.
Nitrogen Cycle: Nitrogen fixation, nitrification, assimilation, ammonification, denitrification.
Phosphorus Cycle: Weathering/erosion, assimilation, waste/decomposition, sedimentation.
Eutrophication: Excess nutrients can cause algal blooms and kill aquatic life.

Photosynthesis

Photosynthesis converts water and carbon dioxide into glucose and oxygen using sunlight.
Two parts: light-dependent reactions (water, light, ATP, NADPH, oxygen production) and light-independent reactions (CO2, ATP, NADPH, glucose production).
Chloroplasts contain pigments that capture light energy, particularly chlorophyll.
ATP stores energy in chemical bonds.

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Description

This quiz covers fundamental principles of scientific methodology, including observation, inference, and hypothesis testing. It also explores the structures of controlled experiments, data collection methods, and the importance of peer analysis in research. Test your understanding of how scientists investigate and explain natural events.