Midterm Flashcards
Weather
Weather refers to the atmospheric conditions in a specific place at a specific time, including temperature, humidity, precipitation, wind speed, and atmospheric pressure
Climate
Climate refers to the long-term average of weather conditions in a particular region over a period of several decades or more.
Describe how the earth’s tilted axis, the uneven heating of the earth, seasons, the earth’s rotation, air and ocean currents, weather, and climate are interrelated.
Earth’s Tilted Axis: This tilt causes variations in the angle and intensity of sunlight received at different latitudes, leading to seasonal changes.
Uneven Heating of the Earth: Differences in solar radiation due to curvature and rotation of the Earth lead to variations in temperature and pressure.
Seasons: Result from the Earth’s axial tilt, affecting the angle and duration of sunlight.
Earth’s Rotation: Causes the Coriolis effect, influencing wind patterns and ocean currents.
Air and Ocean Currents: Distribute heat and moisture around the globe, influencing climate patterns.
Weather and Climate: Weather events (short-term) contribute to climate (long-term) patterns and vice versa.
Describe El Niño and La Niña and their effects on the weather.
El Niño: Refers to a periodic warming of sea surface temperatures in the central and eastern Pacific Ocean, influencing global weather patterns.
La Niña: The opposite of El Niño, La Niña is characterized by cooler-than-average sea surface temperatures in the central and eastern Pacific Ocean.
Explain the importance of ocean currents to nutrient cycles and productivity
Nutrient Cycling: Ocean currents play a crucial role in distributing nutrients like nitrogen, phosphorus, and iron throughout the ocean.
Productivity: Nutrient-rich ocean currents contribute to high primary productivity in marine environments, supporting the growth of phytoplankton and other marine organisms that form the base of the ocean food web.
Ph
pH is a measure of the acidity or alkalinity of a solution. It is a scale ranging from 0 to 14, where a pH of 7 is neutral. Solutions with a pH below 7 are acidic, and those above 7 are alkaline (basic).
Describe the interplay of ocean pH and calcium availability to aquatic organisms.
Ocean acidification reduces the availability of calcium carbonate in seawater. This affects marine organisms such as corals, shellfish, and plankton that rely on calcium carbonate to build their shells or skeletons. Lower pH levels can make it harder for these organisms to form and maintain their structures, potentially impacting their survival and entire ecosystems.
Ocean Acidification
Ocean acidification is the ongoing decrease in the pH of the Earth’s oceans, primarily caused by the uptake of carbon dioxide (CO2) from the atmosphere. This process increases the acidity of seawater
Climate Change
Climate change refers to long-term changes in temperature, precipitation, and other atmospheric conditions over decades to millions of years.
List the major greenhouse gases.
Major greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), water vapor (H2O), and ozone (O3).
Carbon sink
A carbon sink is a reservoir or natural environment that absorbs and stores carbon dioxide from the atmosphere.
Describe the role of carbon sinks in controlling the levels of carbon dioxide in the atmosphere.
Carbon sinks help regulate the amount of carbon dioxide (CO2) in the atmosphere by absorbing more CO2 than they release. They play a critical role in mitigating climate change by removing CO2 from the air and storing it for varying periods.
Identify the causes, the role of human activity, and the environmental effects of global warming (global climate change).
Global warming, driven by human activities such as burning fossil fuels, deforestation, and industrial processes, increases greenhouse gas concentrations in the atmosphere. This leads to rising temperatures, altered weather patterns, sea level rise, melting ice caps, and other environmental impacts.
Define a biogeochemical cycle and describe how the biotic and abiotic factors in the ecosystem are involved.
A biogeochemical cycle is the pathway through which a chemical element or molecule moves through both biotic (living) and abiotic (non-living) components of an ecosystem, cycling between biological, geological, and chemical processes.
Water cycle
the continuous movement of water on, above, and below the surface of the Earth. It involves processes such as evaporation, condensation, precipitation, runoff, and transpiration.
Biotic and abiotic
Biotic factors are living components of an ecosystem (organisms), while abiotic factors are non-living components (like water, soil, air, temperature, sunlight).
carbon cycle
The carbon cycle is the process by which carbon is exchanged between the atmosphere, oceans, biosphere, and geosphere. It involves processes such as photosynthesis, respiration, decomposition, and geological processes like weathering and volcanic activity.
Describe organic and inorganic carbon sources. (For our purposes, inorganic sources are non-living sources).
Organic carbon sources are derived from living organisms or their remains (e.g., plants, animals, and their products). Inorganic carbon sources are non-living sources, such as carbon dioxide (CO2) in the atmosphere, carbonates, and bicarbonates in rocks and minerals.
Describe how hydrogen bonds hold individual water molecules together and the energy required to break these hydrogen bonds.
Hydrogen bonds between water molecules give water its unique properties, such as high surface tension and cohesion. Breaking these bonds requires energy, which is why water has a relatively high heat capacity.
hydrogen bond
A hydrogen bond is a weak electrostatic attraction between a hydrogen atom covalently bonded to a more electronegative atom (like oxygen or nitrogen) and another electronegative atom.
Heat of vaporization
Heat of vaporization (or evaporation) is the amount of heat energy required to convert a liquid into a gas at constant temperature and pressure.
Capillary action
Capillary action is the movement of liquid through a narrow space (like a tube or porous material) due to adhesive and cohesive forces. It helps transport water and nutrients in plants.
three phases of water
Water exists in three phases: solid (ice), liquid (water), and gas (water vapor). Changes between these phases involve the absorption or release of energy.
Relate hydrogen bonds and phases of water to evaporation and precipitation in the water cycle.
Hydrogen bonds influence the phase changes of water. Energy from the sun breaks hydrogen bonds during evaporation, turning liquid water into water vapor. Condensation (formation of clouds) occurs when water vapor condenses back into liquid water droplets, leading to precipitation.
Define evaporation, precipitation, runoff, and transpiration.
Evaporation: The process by which water changes from a liquid to a gas (water vapor) due to heat.
Precipitation: Any form of water (rain, snow, sleet, hail) falling from the atmosphere to the Earth’s surface.
Runoff: The flow of water over the Earth’s surface into streams, rivers, and oceans.
Transpiration: The release of water vapor from plants through their leaves.
Diagram and explain the major stages of the water (hydrologic) cycle including evaporation, precipitation, runoff, and transpiration.
The water cycle involves processes like evaporation, condensation, precipitation, runoff, and transpiration, which continuously recycle water between the atmosphere, land, and oceans.
Define and identify carbon sinks in the environment.
Carbon sinks are reservoirs or environments that absorb more carbon from the atmosphere than they release. Examples include forests, oceans, wetlands, and soil. These sinks help regulate atmospheric carbon dioxide levels and mitigate climate change.
Diagram and explain the major stages of the carbon cycle.
The carbon cycle includes processes such as photosynthesis, respiration, decomposition, combustion, and geological processes (weathering, erosion, and sedimentation) that transfer carbon between the atmosphere, oceans, biosphere, and geosphere.
nitrogen cycle
The nitrogen cycle is the biogeochemical cycle that describes how nitrogen is converted between its various chemical forms in the environment. It includes nitrogen fixation, nitrification, ammonification, and denitrification.
phosphorus cycle
The phosphorus cycle describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. It involves processes such as weathering of rocks, absorption by plants, and recycling through organisms and the environment.
Define nitrogen fixation, ammonification, nitrification, and denitrification.
Nitrogen Fixation: The conversion of atmospheric nitrogen (N2) into ammonia (NH3) or other nitrogen compounds by nitrogen-fixing bacteria. This can be either biological (by bacteria) or industrial (via Haber-Bosch process).
Ammonification: The process where organic nitrogen from dead organisms and waste is converted into ammonia (NH3) by decomposing bacteria and fungi.
Nitrification: The conversion of ammonia (NH3) into nitrites (NO2-) and then into nitrates (NO3-) by nitrifying bacteria (Nitrosomonas and Nitrobacter).
Denitrification: The conversion of nitrates (NO3-) back into nitrogen gas (N2) by denitrifying bacteria, which completes the nitrogen cycle by returning nitrogen to the atmosphere.
Diagram and explain the major parts of the local and geologic phosphorus cycles.
The local phosphorus cycle involves the movement of phosphorus within ecosystems, primarily through biological processes like uptake by plants, consumption by animals, and decomposition. The geologic phosphorus cycle involves the slow weathering of rocks and sedimentary processes that release phosphorus into the environment.
Diagram and explain the major parts of the nitrogen cycle, including nitrogen fixation, ammonification, nitrification, and denitrification.
The nitrogen cycle involves processes like nitrogen fixation (by bacteria and lightning), ammonification (decay of organic matter to ammonia), nitrification (conversion of ammonia to nitrates), and denitrification (return of nitrogen to the atmosphere). These processes recycle nitrogen between the atmosphere, soil, water, and living organisms.
Explain the importance of the water, nitrogen, phosphorus, and carbon cycles to living organisms and how these elements move through plants.
Water cycle: Essential for hydration, photosynthesis, and transport of nutrients in plants.
Nitrogen cycle: Provides essential nitrogen for protein synthesis and other biomolecules.
Phosphorus cycle: Critical for ATP production, DNA, RNA, and cell membranes in organisms.
Carbon cycle: Basis for organic molecules like carbohydrates, lipids, proteins, and nucleic acids.
monomer and polymer
Monomer: A small molecule that can chemically bond with other monomers to form a polymer.
Polymer: A large molecule composed of repeating structural units (monomers) bonded together.
- List the four major macromolecule groups (polymers) found in plant and animal tissues.
Carbohydrates
Proteins
Lipids (fats)
Nucleic acids (DNA and RNA)
Identify the major monomers and polymers produced by plants and explain their relationship to photosynthesis and transpiration.
Monomers like glucose (from carbohydrates) and amino acids (from proteins) are used in photosynthesis and other metabolic processes.
Polymers like starch (carbohydrate storage) and cellulose (structural carbohydrate) are produced by plants.
Describe how the elements (C, H, O, N, and P) found in the plant’s glucose, amino acids, fatty acids, and nucleotides entered the plant.
Carbon (C) and oxygen (O) are obtained from atmospheric CO2 and water (H2O) during photosynthesis.
Nitrogen (N) is absorbed as nitrates (NO3-) or ammonium (NH4+) from the
soil.
Phosphorus (P) is absorbed as phosphate (PO4^3-) from the soil.
Describe the effect on plant growth if the elements that make up each of the major macromolecule groups are limited or unavailable.
Limited nitrogen or phosphorus can lead to stunted growth, reduced photosynthesis, and chlorosis (yellowing of leaves) due to nutrient deficiency.
Insufficient carbon or water can also impair plant growth and metabolic processes.
eutrophication
Eutrophication is the process by which water bodies become overly enriched with nutrients (particularly nitrogen and phosphorus), leading to excessive growth of algae and aquatic plants. This can deplete oxygen levels and disrupt aquatic ecosystems.
Identify the characteristics of oligotrophic and eutrophic lakes.
Oligotrophic Lakes: Low-nutrient lakes with clear water, low algae production, and high oxygen levels.
Eutrophic Lakes: High-nutrient lakes with excessive algae growth, cloudy water, and potentially low oxygen levels due to decomposition of organic matter.
photosynthesis
Photosynthesis is the biochemical process by which autotrophic organisms, such as plants, algae, and some bacteria, convert light energy from the sun into chemical energy stored in glucose (sugar).
cellular respiration
Cellular respiration is the biochemical process that releases energy from organic molecules (like glucose) within cells to produce ATP (adenosine triphosphate), which is used as cellular energy. It typically involves the consumption of oxygen and production of carbon dioxide.
Identify the role of autotrophs in photosynthesis.
Autotrophs capture light energy and use it to convert carbon dioxide (CO2) and water (H2O) into glucose (C6H12O6) and oxygen (O2) during photosynthesis.
autotroph
An autotroph is an organism that can produce its own food (organic molecules) from inorganic substances, typically using light energy (photosynthesis) or chemical energy (chemosynthesis).
primary productiviy
Primary productivity is the rate at which autotrophic organisms (such as plants) convert solar or chemical energy into organic compounds through photosynthesis or chemosynthesis.
Identify the organelle in plants where cellular respiration takes place.
Cellular respiration primarily occurs in the mitochondria of plant cells (and all eukaryotic cells), where glucose is broken down to release energy.
Describe the relationship between photosynthesis and cellular respiration.
Photosynthesis produces glucose and oxygen using carbon dioxide and water with the help of sunlight. Cellular respiration then uses this glucose and oxygen to produce ATP, releasing carbon dioxide and water as byproducts. Thus, the two processes are complementary and interconnected in the carbon cycle.
Write the overall reaction for photosynthesis, identifying the substrates and products.
The overall reaction for photosynthesis is:
6CO2 + 6H2O + light energy → C6H12O6 + 6O2
(Carbon dioxide + water + light energy → glucose + oxygen)
chlorophyll role in photosynthesis
Pigment molecule that captures light energy for photosynthesis.
water role in photosynthesis
Provides electrons and protons (H+) during photosynthesis.
the different wavelengths of light role in photosynthesis
Chlorophyll absorbs specific wavelengths of light (mainly red and blue) to drive the photosynthetic reactions.
enzymes role in photosynthesis
Facilitate biochemical reactions involved in photosynthesis.
carbon dioxide role in photosynthesis
Source of carbon used to build glucose molecules.
Describe how C3, C4, and CAM plants differ in their strategies for using water and carbon dioxide during photosynthesis.
C3 Plants: Use the Calvin cycle for carbon fixation under normal conditions but can experience water loss in hot and dry environments.
C4 Plants: Use an additional step (C4 pathway) to minimize water loss by concentrating CO2 in specialized cells (mesophyll and bundle sheath).
CAM Plants (Crassulacean Acid Metabolism): Open stomata at night to reduce water loss and fix carbon dioxide into organic acids, which are broken down during the day for photosynthesis.
Describe how the elements (C, H, and O) found in the plant’s glucose entered the plant.
Carbon (C) is obtained from atmospheric carbon dioxide (CO2) during photosynthesis.
Hydrogen (H) and oxygen (O) are obtained from water (H2O) during photosynthesis.
Trace the flow of energy in the ecosystem among the following: sunlight, decomposers, heterotrophs (consumers), and autotrophs (producers).
Sunlight provides energy for photosynthesis by autotrophs (producers), who convert it into chemical energy stored in organic molecules. Heterotrophs (consumers) obtain energy by consuming organic matter (other organisms), and decomposers break down organic matter to recycle nutrients back into the ecosystem.
Explain why elements can be recycled but energy cannot be recycled.
Elements (such as carbon, nitrogen, and phosphorus) can be cycled through biogeochemical cycles (e.g., carbon cycle, nitrogen cycle) as they are conserved and reused in ecosystems. In contrast, energy flows through ecosystems and is eventually lost as heat, making it unavailable for reuse (following the second law of thermodynamics). Therefore, energy must continually enter ecosystems from an external source (sunlight) to sustain life processes.
List three problems that plants faced when moving from water to a land environment.
Desiccation (Drying Out): Terrestrial environments pose a risk of dehydration for plants, as they are no longer surrounded by water.
Support and Structure: Plants needed to develop structural support to stand upright against gravity without the buoyant support of water.
Reproduction: Plants had to evolve strategies for reproduction on land, including protection of gametes from drying out and dispersal of offspring.
Provide evidence to defend the position that plants share a common ancestor with green algae.
Both plants and green algae contain chlorophylls a and b, as well as other pigments, suggesting a common photosynthetic ancestor.
They share similar cell wall compositions, including cellulose.
Molecular studies show genetic similarities between modern plants and green algae, supporting a shared evolutionary origin.
Describe adaptations of vascular plants that have contributed to their success on land.
Vascular tissue (xylem and phloem) for efficient water and nutrient transport.
Roots for anchorage and absorption of water and minerals.
Lignin in cell walls for structural support, allowing plants to grow tall and compete for sunlight.
Describe two adaptations that allowed bryophytes (mosses) to move onto land and explain why bryophytes still depend on water for reproduction.
Adaptations: Bryophytes developed cuticles and stomata to reduce water loss and absorb nutrients from the air and soil. They also evolved specialized structures (rhizoids) for anchorage.
Dependence on Water: Bryophytes still depend on water for reproduction because their sperm cells require a film of water to swim to the egg cells for fertilization.
seed and pollen grain
Seed: A structure formed from the fertilized ovule of a plant, containing an embryo and stored nutrients, protected by a seed coat. Seeds provide protection and nutrients for the developing embryo.
Pollen Grain: Microscopic male gametophyte of seed plants (gymnosperms and angiosperms), containing the male gametes (sperm cells). Pollen grains are carried by wind or animals to reach female reproductive organs for fertilization.
Describe the adaptations that plants have for survival in different biomes.
Xerophytes (desert plants) have adaptations like succulence, reduced leaves, and deep roots to conserve water.
Hydrophytes (aquatic plants) have adaptations like floating leaves, flexible stems, and reduced cuticle to thrive in aquatic environments.
Mesophytes (temperate plants) have moderate adaptations for temperate climates, such as standard leaf structure and water management.
Describe the structure of a seed and its importance to the colonization of land.
A seed consists of an embryo (developing plant), stored nutrients (endosperm), and a protective seed coat (testa). Seeds enable plants to reproduce and spread on land by protecting the embryo from desiccation, mechanical damage, and predation.
