Midterm Flashcards
(163 cards)
1
Q
Weather
A
Weather refers to the atmospheric conditions in a specific place at a specific time, including temperature, humidity, precipitation, wind speed, and atmospheric pressure
2
Q
Climate
A
Climate refers to the long-term average of weather conditions in a particular region over a period of several decades or more.
3
Q
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.
A
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.
4
Q
Describe El Niño and La Niña and their effects on the weather.
A
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.
5
Q
Explain the importance of ocean currents to nutrient cycles and productivity
A
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.
6
Q
Ph
A
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).
7
Q
Describe the interplay of ocean pH and calcium availability to aquatic organisms.
A
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.
7
Q
Ocean Acidification
A
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
8
Q
Climate Change
A
Climate change refers to long-term changes in temperature, precipitation, and other atmospheric conditions over decades to millions of years.
9
Q
List the major greenhouse gases.
A
Major greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), water vapor (H2O), and ozone (O3).
10
Q
Carbon sink
A
A carbon sink is a reservoir or natural environment that absorbs and stores carbon dioxide from the atmosphere.
11
Q
Describe the role of carbon sinks in controlling the levels of carbon dioxide in the atmosphere.
A
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.
12
Q
Identify the causes, the role of human activity, and the environmental effects of global warming (global climate change).
A
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.
13
Q
Define a biogeochemical cycle and describe how the biotic and abiotic factors in the ecosystem are involved.
A
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.
14
Q
Water cycle
A
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.
15
Q
Biotic and abiotic
A
Biotic factors are living components of an ecosystem (organisms), while abiotic factors are non-living components (like water, soil, air, temperature, sunlight).
16
Q
carbon cycle
A
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.
17
Q
Describe organic and inorganic carbon sources. (For our purposes, inorganic sources are non-living sources).
A
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.
18
Q
Describe how hydrogen bonds hold individual water molecules together and the energy required to break these hydrogen bonds.
A
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.
18
Q
hydrogen bond
A
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.
19
Q
Heat of vaporization
A
Heat of vaporization (or evaporation) is the amount of heat energy required to convert a liquid into a gas at constant temperature and pressure.
20
Q
Capillary action
A
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.
21
Q
three phases of water
A
Water exists in three phases: solid (ice), liquid (water), and gas (water vapor). Changes between these phases involve the absorption or release of energy.
22
Q
Relate hydrogen bonds and phases of water to evaporation and precipitation in the water cycle.
A
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.
23
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.
24
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.
25
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.
26
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.
26
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.
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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.
28
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.
29
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.
29
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.
30
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.
31
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.
31
8. List the four major macromolecule groups (polymers) found in plant and animal tissues.
Carbohydrates
Proteins
Lipids (fats)
Nucleic acids (DNA and RNA)
32
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.
33
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.
34
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.
35
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.
36
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.
37
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).
38
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.
39
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.
39
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).
40
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.
41
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.
42
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.
43
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)
44
chlorophyll role in photosynthesis
Pigment molecule that captures light energy for photosynthesis.
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water role in photosynthesis
Provides electrons and protons (H+) during photosynthesis.
46
the different wavelengths of light role in photosynthesis
Chlorophyll absorbs specific wavelengths of light (mainly red and blue) to drive the photosynthetic reactions.
47
enzymes role in photosynthesis
Facilitate biochemical reactions involved in photosynthesis.
48
carbon dioxide role in photosynthesis
Source of carbon used to build glucose molecules.
48
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.
49
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.
50
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.
51
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.
52
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.
53
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.
54
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.
55
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.
56
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.
57
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.
58
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.
59
Describe the structure of a pollen grain and its importance to the colonization of land.
A pollen grain is a structure containing the male gametophyte and male gametes (sperm cells) of seed plants. Pollen grains can be dispersed over long distances by wind or animals, enabling plants to reproduce without water.
60
Describe the adaptations of seeds that aid in dispersal.
Seeds have adaptations like wings, hooks, or fleshy fruits to aid in dispersal by wind, water, or animals to new habitats.
Some seeds have mechanisms for dormancy, allowing them to remain viable until conditions are favorable for germination.
61
pollinator
A pollinator is an organism (often insects, birds, bats, or other animals) that transfers pollen from the male reproductive organs (anthers) to the female reproductive organs (stigma) of flowers, facilitating fertilization and seed production.
62
co-evolution
Co-evolution is the evolutionary process where two or more species reciprocally influence each other's adaptations over time, often leading to specialized interactions or dependencies.
63
Discuss the simultaneous evolution (co-evolution) of flowering plants and their pollinators.
Flowering plants (angiosperms) and their pollinators (such as bees, butterflies, and birds) have co-evolved specialized traits that benefit both parties. For example, flowers may develop specific shapes, colors, and scents to attract pollinators, while pollinators benefit from the nectar or pollen provided by the flowers. This co-evolution has contributed to the diversity and success of both groups in terrestrial ecosystems.
64
Define gametophyte and sporophyte and identify each as haploid or diploid.
Gametophyte: The gametophyte is the haploid (n) generation in the life cycle of plants. It produces gametes (sex cells) through mitosis. In some plants, like mosses and ferns, the gametophyte is the dominant generation.
Sporophyte: The sporophyte is the diploid (2n) generation in the plant life cycle. It produces spores through meiosis, which develop into the gametophyte generation. In most vascular plants (ferns, conifers, flowering plants), the sporophyte is the dominant generation.
65
Explain alternation of generations and discuss it as a trend in plant evolution including the terms gametophyte and sporophyte.
Alternation of generations is a life cycle pattern where plants alternate between haploid (gametophyte) and diploid (sporophyte) generations. This pattern evolved as a way for plants to adapt to different environments and reproductive strategies. The gametophyte generation produces gametes, which fuse to form the diploid sporophyte generation. The sporophyte generation then produces spores that develop into the gametophyte generation, completing the cycle.
65
Identify the characteristics that separate algae, mosses, ferns, conifers, and flowering plants
Algae: Simple, aquatic, mostly unicellular or multicellular organisms lacking true roots, stems, or leaves.
Mosses: Small, non-vascular plants with a dominant gametophyte stage, lacking true roots and leaves.
Ferns: Vascular plants with leaves (fronds) and true roots, exhibiting a dominant sporophyte stage with conspicuous fronds and reproductive structures called sporangia.
Conifers: Gymnosperms with needle-like or scale-like leaves, cones (male and female), and seeds exposed on cones.
Flowering Plants (Angiosperms): Vascular plants with flowers and seeds enclosed within fruits, exhibiting diverse forms and reproductive strategies.
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gymnosperm and conifer
Gymnosperm: A gymnosperm is a seed-producing plant that does not produce flowers or fruits. Their seeds are exposed on cones or other structures.
Conifer: Conifers are a group of gymnosperms characterized by needle-like or scale-like leaves and cones that bear seeds. Examples include pine, spruce, fir, and cedar trees.
67
List the parts of the plant that would be considered vegetables and the parts that would be fruit
Vegetables: Roots (carrots, beets), tubers (potatoes), stems (celery), leaves (lettuce, spinach), and flower buds (broccoli, cauliflower).
Fruit: The mature ovary of a flowering plant containing seeds. Examples include apples, tomatoes, peppers, and cucumbers.
68
Define monocot and dicot.
Monocot (Monocotyledon): A flowering plant with seeds that have one cotyledon (seed leaf). Monocots have parallel leaf veins and flower parts in multiples of three (e.g., lilies, grasses).
Dicot (Dicotyledon): A flowering plant with seeds that have two cotyledons (seed leaves). Dicots have branched leaf veins and flower parts in multiples of four or five (e.g., roses, beans).
69
Identify the similarities and differences between monocots and dicots.
Similarities:
Both are flowering plants (angiosperms).
Both have roots, stems, leaves, flowers, and seeds.
Differences:
Roots: Monocots typically have fibrous roots, while dicots often have taproots.
Stems: Monocots have scattered vascular bundles, while dicots have a ring arrangement.
Leaves: Monocots have parallel veins, while dicots have net-like (reticulate) veins.
Flowers: Monocots have flower parts in multiples of three, while dicots have flower parts in multiples of four or five.
69
xylem
Xylem is a vascular tissue in plants responsible for transporting water and dissolved minerals from the roots to the rest of the plant.
70
phloem
Phloem is another type of vascular tissue in plants that transports sugars (mainly sucrose) and other organic compounds (like amino acids) from the leaves (or other photosynthetic tissues) to other parts of the plant, including roots, fruits, and flowers.
71
Identify what nutrients are found in xylem and phloem.
Xylem: Water, dissolved minerals (such as potassium, calcium, and magnesium).
Phloem: Sugars (sucrose), amino acids, hormones, and other organic compounds.
72
Identify the direction of flow of nutrients in the xylem and phloem.
Xylem: Flows upwards (from roots to shoots) due to transpiration pull and root pressure.
Phloem: Flows bidirectionally (both upwards and downwards) through a process called translocation.
73
meristem
Meristem is a type of plant tissue composed of undifferentiated cells capable of continuous cell division. Meristems are responsible for plant growth and development.
74
hormone
A hormone is a chemical messenger produced by plants that regulates various physiological processes, including growth, development, and response to environmental stimuli.
74
Identify the role of meristems in the growth of plants in height and width.
Apical Meristem: Found at the tips of roots and shoots, responsible for primary growth (lengthening of roots and shoots).
Lateral (or Cambium) Meristem: Found in the vascular cambium and cork cambium, responsible for secondary growth (increased width/girth of stems and roots).
75
apical dominance
Apical dominance is the phenomenon where the apical (topmost) bud of a plant inhibits the growth of lateral (side) buds, promoting vertical growth. This is often regulated by auxin hormones.
75
Identify the function and sources of auxins and ethylene gas in the plant.
Auxins: Promote cell elongation, apical dominance, and root initiation. Sources include apical meristems, young leaves, and developing fruits.
Ethylene Gas: Regulates fruit ripening, leaf abscission (shedding), and responses to stress. Ethylene is produced in response to aging, injury, or other environmental cues.
76
Define phototropism and gravitropism.
Phototropism: Plant growth response directed by light, where plants grow towards light (positive phototropism) or away from light (negative phototropism).
Gravitropism: Plant growth response directed by gravity, where roots grow downwards (positive gravitropism) and shoots grow upwards (negative gravitropism).
77
Identify the role of auxins in phototropism and gravitropism.
Phototropism: Auxins accumulate on the shaded side of the plant, causing cells to elongate more on that side and bending towards the light source.
Gravitropism: Auxins redistribute in response to gravity, inhibiting cell elongation on the lower side of roots and promoting it on the upper side of shoots, allowing roots to grow downwards and shoots upwards.
78
Identify how plant hormones are used commercially.
Auxins: Used in agriculture to promote root growth (rooting hormones) and control fruit development and ripening.
Gibberellins: Used to induce flowering, increase fruit size, and break seed dormancy.
Cytokinins: Used in tissue culture for plant propagation and to delay aging (senescence) in harvested fruits and vegetables.
Ethylene: Used to ripen fruits artificially and control fruit drop and flower senescence.
78
Archaea characteristics
Cell Type: Prokaryotic
Number of Cells: Mostly unicellular
Acquiring Nutrients: Mostly heterotrophic (some are autotrophic)
Movement: Mostly non-motile
Cell Wall: Present
Cell Wall Composition: Usually made of pseudopeptidoglycan or other unique substances
79
bacteria Characteristics
Cell Type: Prokaryotic
Number of Cells: Mostly unicellular
Acquiring Nutrients: Can be autotrophic (photosynthetic or chemosynthetic) or heterotrophic (including decomposers)
Movement: Motile or non-motile
Cell Wall: Present
Cell Wall Composition: Contains peptidoglycan
79
Protista Characteristics
Cell Type: Eukaryotic
Number of Cells: Mostly unicellular; some are multicellular
Acquiring Nutrients: Can be autotrophic (algae) or heterotrophic (protozoa)
Movement: Motile (e.g., using flagella or cilia) or non-motile
Cell Wall: Present in some (e.g., algae)
Cell Wall Composition: Varies (e.g., cellulose in some algae)
80
Fungi Characteristics
Cell Type: Eukaryotic
Number of Cells: Most are multicellular; some are unicellular (yeasts)
Acquiring Nutrients: Heterotrophic (decomposers or parasites)
Movement: Mostly non-motile
Cell Wall: Present
Cell Wall Composition: Contains chitin
81
Animalia Characteristics
Cell Type: Eukaryotic
Number of Cells: Most are multicellular; some are unicellular (e.g., protozoa)
Acquiring Nutrients: Heterotrophic (consumers)
Movement: Motile
Cell Wall: Absent (except for some protozoa)
Cell Wall Composition: N/A
81
Plantae Characteristics
Cell Type: Eukaryotic
Number of Cells: Multicellular
Acquiring Nutrients: Autotrophic (photosynthesis)
Movement: Mostly non-motile
Cell Wall: Present
Cell Wall Composition: Contains cellulose
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ecosystem
An ecosystem is a community of living organisms (biotic factors) interacting with their physical environment (abiotic factors) in a specific area.
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community
A community is a group of populations of different species living and interacting in the same area at the same time.
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trophic level
A trophic level is a position in the food chain or food web hierarchy, representing the organism's energy source and place in the ecosystem.
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biotic and abiotic
Biotic: Living components of an ecosystem (e.g., plants, animals, microbes).
Abiotic: Non-living components of an ecosystem (e.g., sunlight, water, soil).
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autotoph
Convert solar energy into organic compounds (e.g., plants through photosynthesis).
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heterotroph
Primary Consumers: Herbivores that consume producers.
Secondary Consumers: Carnivores that eat herbivores.
Tertiary Consumers: Carnivores that eat secondary consumers.
85
producers
Convert solar energy into organic compounds (e.g., plants through photosynthesis).
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secondary consumers
Carnivores that eat herbivores.
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primary consumers
Herbivores that consume producers.
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decomposers
Break down organic matter (dead plants and animals) into simpler substances (e.g., bacteria, fungi).
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tertiary consumers
Carnivores that eat secondary consumers.
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carnivores
eat other animals
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detritivores
Consume decomposing organic matter (e.g., earthworms, millipedes).
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sapropyhte
Organisms that obtain nutrients from decaying organic matter (e.g., certain fungi).
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herbivores
eat plants
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omnivores
eat both plants and animals
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parasite
Live on or in another organism (host) and derive nutrients at the host's expense.
92
Define and give an example of a food chain.
A food chain is a linear sequence of organisms where each organism serves as a food source for the next. Example: Grass → Rabbit → Fox.
93
Explain the value of diversity to food webs.
Diversity in food webs increases stability and resilience of ecosystems by providing redundancy and multiple pathways for energy flow. It allows for efficient nutrient cycling and reduces the risk of population crashes due to disturbances.
93
Define and give an example of a food web.
A food web is a network of interconnected food chains, illustrating the feeding relationships within an ecosystem. Example: Grass → Grasshopper → Frog → Snake; Grass → Rabbit → Hawk.
94
Describe the relationship between food chains and a food web.
Food chains are simple linear pathways of energy transfer, whereas food webs depict complex interactions among multiple organisms and trophic levels.
95
Describe the interrelationship of energy acquisition among the organisms found in food chains and food webs.
Energy acquisition in ecosystems involves the transfer of energy from one trophic level to another. Producers (autotrophs) acquire energy from sunlight, which is then passed on to primary consumers (herbivores), secondary consumers (carnivores), and so on, through feeding interactions in food chains and food webs.
95
Identify the primary energy source for all living organisms in the ecosystem.
The primary energy source for all living organisms in ecosystems is sunlight. Sunlight is captured by autotrophic organisms (such as plants) through photosynthesis, converting solar energy into chemical energy stored in organic compounds.
96
pyramid of biomass
A pyramid of biomass represents the total dry weight of organisms (biomass) at each trophic level in an ecosystem. Typically, biomass decreases at higher trophic levels due to energy loss through metabolic processes and inefficiencies in energy transfer.
97
pyramid of energy
A pyramid of energy illustrates the flow of energy through trophic levels in an ecosystem. It shows the amount of energy transferred from one trophic level to the next, with most energy being lost as heat during respiration and metabolic processes.
97
Discuss the efficiency of a typical ecosystem and the energy stored at each trophic or feeding level.
Ecosystems are generally inefficient in terms of energy transfer between trophic levels. Only a fraction of the energy available at one trophic level is transferred to the next level, with the majority of energy lost as heat. As a result, the biomass and energy decrease as you move up the trophic levels.
98
Define biological magnification and give examples.
Biological magnification (or biomagnification) is the process by which certain substances (such as toxic chemicals or pollutants) become more concentrated in organisms at higher trophic levels of a food chain. Examples include mercury accumulation in fish due to environmental pollution, or DDT accumulation in birds of prey.
99
Describe why consuming a diet of producers is more efficient in terms of energy, production of biomass, and avoidance of biological magnification.
Consuming a diet primarily composed of producers (plants) is more efficient because it allows organisms to access the most direct and abundant source of energy (sunlight) through photosynthesis. This avoids the inefficiencies associated with energy loss in food chains and reduces the risk of accumulating toxic substances through biological magnification.
99
Identify which trophic level is in most danger.
Generally, top-level predators (tertiary consumers) in a food chain are most at risk of accumulating high concentrations of harmful substances through biological magnification.
99
Identify the characteristics that a substance must have to be a good candidate for biological magnification.
Substances that are persistent (do not break down easily), fat-soluble, and toxic tend to be good candidates for biological magnification. These substances can accumulate in organisms and become more concentrated at higher trophic levels.
99
community
A community is a group of populations of different species living and interacting in the same area at the same time.
100
define pioneer, transition, and climax communities.
Pioneer Community: The first community to establish in a barren or disturbed area, typically consisting of hardy, fast-growing species.
Transition Community: Intermediate stage in ecological succession, where pioneer species are gradually replaced by more diverse and complex species.
Climax Community: The final stage of ecological succession, characterized by a stable, diverse community that remains in equilibrium under prevailing environmental conditions.
101
succession
Succession is the process of ecological change in an ecosystem over time, where a series of communities replace one another until a stable, climax community is established. Succession can be primary (starting from bare rock or soil) or secondary (following disturbance in an existing ecosystem).
101
trophic levels
Trophic levels refer to the hierarchical levels in an ecosystem based on an organism's feeding position in a food chain or food web. The typical trophic levels are:
Producers (Primary Producers):
Primary Consumers (Herbivores):
Secondary Consumers (Carnivores): Tertiary Consumers (Top Predators):
Additional levels include quaternary consumers and decomposers (detritivores).
102
producers
Producers are organisms that produce organic compounds (e.g., glucose) from inorganic substances using sunlight (photosynthesis) or chemical energy (chemosynthesis). They form the base of the food chain by providing energy for other organisms.
103
food chain
food chain represents a linear sequence of trophic interactions
103
food web
food web provides a more comprehensive and realistic depiction of the complex feeding relationships and energy flow among organisms within an ecosystem.
103
consumers
Consumers are organisms that obtain energy by consuming other organisms. They include herbivores (primary consumers), carnivores (secondary and tertiary consumers), and omnivores that consume both plants and animals.
103
Compare running-water ecosystems and standing-water ecosystems.
Running-Water Ecosystems (Lotic): Include rivers, streams, and creeks with flowing water. Characterized by faster water flow, varying oxygen levels, and diverse habitats.
Standing-Water Ecosystems (Lentic): Include lakes, ponds, and wetlands with still or slow-moving water. Characterized by stratification, seasonal turnover, and distinct aquatic zones.
104
Explain how seasonal changes affect freshwater ecosystems.
Seasonal changes such as temperature variations, precipitation, and daylight duration influence freshwater ecosystems by affecting water levels, nutrient availability, and the life cycles of aquatic organisms (e.g., breeding, migration, hibernation).
105
Identify the characteristics that distinguish freshwater and saltwater ecosystems.
Freshwater Ecosystems: Low salinity (<0.5 ppt), dominated by lakes, rivers, ponds, and wetlands.
Saltwater Ecosystems (Marine Ecosystems): High salinity (approx. 35 ppt), dominated by oceans, seas, and estuaries.
106
Identify the characteristics of estuaries and oceans.
Estuaries: Coastal areas where freshwater rivers and streams meet saltwater oceans, characterized by brackish water and high biodiversity.
Oceans: Large bodies of saltwater covering approximately 70% of Earth's surface, divided into zones based on depth and light penetration (e.g., intertidal, pelagic, benthic).
106
wetland
A wetland is an area of land that is saturated with water, either permanently or seasonally, and supports unique plant and animal species adapted to wet conditions.
106
Identify the value and functions of wetlands.
Wetlands provide crucial ecosystem services, including flood control, water filtration, habitat for wildlife, carbon storage, and recreation.
107
Identify the percentage of wetlands in the U.S. that have disappeared.
Approximately half of the wetlands in the contiguous United States have been lost due to human activities such as agriculture, urbanization, and drainage.
108
Describe what has happened to the wetlands in the U.S.
Wetlands in the U.S. have been drained, filled, or altered for agricultural development, urban expansion, and infrastructure projects, leading to loss of biodiversity and ecosystem services.
109
chemosynthesis
Chemosynthesis is a process whereby certain organisms (mostly bacteria) use chemical energy to produce organic compounds from inorganic substances (e.g., hydrogen sulfide) instead of sunlight.
109
Define hydrothermal vent and identify their location.
Hydrothermal vents are fissures on the seafloor that emit hot, mineral-rich water due to volcanic activity. They are found in areas of tectonic activity, such as mid-ocean ridges.
109
Identify the similarities and differences between photosynthesis and bacterial chemosynthesis.
Similarities: Both processes produce organic compounds (e.g., glucose) using energy from non-solar sources.
Differences: Photosynthesis uses sunlight as the energy source and occurs in plants, algae, and cyanobacteria, whereas chemosynthesis uses chemical energy (from hydrothermal vents) and occurs in certain bacteria.
110
Identify the producers and consumers in the hydrothermal vent ecosystem.
Producers: Chemosynthetic bacteria that convert inorganic compounds into organic matter.
Consumers: Organisms such as tube worms, shrimp, and crabs that feed on chemosynthetic bacteria.
111
Identify the mutualistic relationships found in the hydrothermal vent ecosystem.
Mutualistic relationships in hydrothermal vent ecosystems include symbiotic associations between chemosynthetic bacteria and host organisms (e.g., tube worms), where bacteria provide organic nutrients in exchange for a habitat.
111
Identify the source of energy for chemosynthesis in the hydrothermal vent ecosystem.
The source of energy for chemosynthesis in hydrothermal vent ecosystems is chemical energy derived from minerals (e.g., hydrogen sulfide) released from the vents.
111
biome
A biome is a large ecological area characterized by distinct climate, vegetation, and organisms adapted to specific environmental conditions.
111
Explain the factors that play a role in the development and distribution of biomes.
Climate (temperature, precipitation): Determines the type of vegetation and organisms that can thrive.
Latitude: Influences solar energy received and temperature gradients.
Altitude: Affects temperature and precipitation patterns.
Topography (elevation, slope): Impacts local climate and water availability.
112
Describe the characteristics and location of each biome.
Tundra: Cold, treeless biome with permafrost found in Arctic regions.
Taiga (Boreal Forest): Cold forest biome dominated by coniferous trees, found in subarctic regions.
Temperate Deciduous Forest: Moderate climate with four seasons and broad-leaved deciduous trees.
Tropical Rainforest: Warm and wet biome with high biodiversity, found near the equator.
Grassland (Savanna): Dry biome with grasses and scattered trees, found in tropical and temperate regions.
Desert: Hot and dry biome with sparse vegetation, found in arid regions.
Chaparral: Mediterranean climate biome
with drought-resistant shrubs and grasses.
113
limiting factor
A limiting factor is any environmental factor that restricts the growth, abundance, or distribution of an organism or population within an ecosystem. Examples include temperature, water availability, nutrients, and sunlight.
113
Explain how limiting factors determine the distribution of each biome.
Tundra: Cold temperatures and permafrost limit plant growth.
Desert: Lack of water limits vegetation.
Tropical Rainforest: Consistent warmth and abundant rainfall support lush vegetation.
114
Compare productivity among the various aquatic ecosystems and terrestrial biomes.
Aquatic ecosystems (e.g., coral reefs, estuaries) and terrestrial biomes differ in productivity due to variations in nutrient availability, water supply, and sunlight exposure. Tropical rainforests and coral reefs are highly productive, while deserts and polar regions have lower productivity.
114
Explain the importance of ocean currents to nutrient cycles and productivity.
Ocean currents transport nutrients and heat around the globe, influencing marine productivity and biodiversity. Upwelling zones bring nutrient-rich waters to the surface, supporting plankton growth and higher trophic levels.
115
Describe the general kinds of adaptations found in the vegetation and animals in each biome.
Tundra: Low-growing plants and animals with thick fur or insulation.
Desert: Succulent plants and animals with water-conserving adaptations.
Tropical Rainforest: Tall trees with buttress roots and diverse animal species.
Grassland: Drought-resistant grasses and grazing animals.
Taiga: Coniferous trees with needle-like leaves and hibernating mammals.
116
life zone
life zones represent distinct ecological regions characterized by specific environmental conditions that determine the distribution of plant and animal species. Understanding life zones is essential for studying biodiversity, ecosystem dynamics, and conservation strategies aimed at preserving Earth's diverse habitats and ecosystems.
116
Explain how altitude can mimic latitude.
altitude can mimic latitude by influencing temperature, climate conditions, vegetation patterns, and biological adaptations. Higher altitudes exhibit cooler temperatures and environmental conditions resembling those found at higher latitudes, contributing to diverse ecosystems and ecological niches across different elevations.
117
desertification
Desertification is the process by which fertile land becomes desert, typically as a result of deforestation, overgrazing, or climate change.
118
Identify the causes, the role of human activity, and the environmental effects of desertification.
Causes include overexploitation of land, unsustainable farming practices, and climate change. Human activities such as deforestation and overgrazing contribute to soil degradation and loss of vegetation, leading to decreased biodiversity and land productivity.
119
deforestation
Deforestation is the clearing or removal of forests or trees, primarily for agriculture, logging, or urban development.
120
Identify the causes, the role of human activity, and the environmental effects of deforestation.
Causes include agriculture expansion, logging, and infrastructure development. Deforestation leads to habitat loss, biodiversity decline, soil erosion, and disruption of carbon and nutrient cycles.
121
Describe the impact of the previously listed environmental problems on the biogeochemical (nutrient) cycles.
Desertification and deforestation disrupt nutrient cycles by reducing vegetation cover and soil fertility, leading to nutrient depletion, increased erosion, and loss of ecosystem services.
122
Suggest some possible solutions to the previously listed environmental problems.
Solutions include sustainable land management practices (e.g., afforestation, crop rotation), reforestation efforts, conservation of natural habitats, and international agreements to address climate change and biodiversity loss. Community engagement and education are also critical for promoting sustainable resource use and ecosystem conservation.
