9th grade biology EOC P2

Characteristics of living things

All living organisms require energy, maintain homeostasis, respond to stimuli, reproduce similar offspring, and are made of cells.

Role of mitochondria

Mitochondria are responsible for energy production through ATP formation.

Definition of diffusion

Diffusion is the movement of substances from an area of high concentration to an area of low concentration.

Types of RNA

mRNA carries genetic information, rRNA forms ribosomes, and tRNA brings amino acids to ribosomes.

Homozygous vs. Heterozygous

Homozygous individuals have two identical alleles for a trait, while heterozygous individuals have two different alleles.

Energy flow in ecosystems

Energy flows through ecosystems from sunlight to producers, then to consumers and decomposers, but cannot be recycled.

Natural selection

Natural selection is the process by which organisms with favorable traits survive and reproduce more successfully than others.

Active transport

Active transport is the movement of materials across cell membranes that requires energy.

Ecology definition

Ecology is the scientific study of interactions between organisms and their environment.

Eukaryotes vs. Prokaryotes

Eukaryotes have membrane-bound structures and a true nucleus, while prokaryotes lack these features.

Osmosis

Osmosis is the diffusion of water molecules through a selectively permeable membrane.

Cellular respiration equation

The equation for cellular respiration is C6H12O6 + 6O2 → 6CO2 + 6H2O + energy.

Binomial nomenclature

Binomial nomenclature is the two-word naming system for species, consisting of the genus name (capitalized) and species name (lowercase).

Mutation significance

Mutations are changes in DNA sequences that can lead to genetic variation in a population.

Symbiosis

Symbiosis is a close relationship between two different species where at least one benefits.

Facilitated transport

Facilitated transport involves a transport protein that helps move substances across the plasma membrane by diffusion.

Trophic levels

Trophic levels represent the positions organisms occupy in a food chain, including producers, consumers, and decomposers.

Primary vs. Secondary succession

Primary succession occurs in lifeless areas where soil must form, while secondary succession occurs in areas where a disturbance has cleared existing life.

Function of the nucleus

The nucleus contains DNA, which controls cellular functions.

Enzyme characteristics

Enzymes are proteins that speed up reactions without being consumed, are not permanently altered, and are highly specific to their substrates.

Central dogma of molecular biology

The central dogma describes the flow of genetic information from DNA to RNA to proteins.

Biogeochemical cycles

Biogeochemical cycles are pathways through which essential elements circulate through the environment, such as the carbon and nitrogen cycles.

Define mutualism in symbiotic relationships.

Mutualism is a symbiotic relationship where both species benefit from the interaction.

Endocytosis vs. Exocytosis

Endocytosis is the process of taking in materials by surrounding them with the cell membrane, while exocytosis is the process of expelling materials from the cell.

Taxonomy

Taxonomy is the science of classifying and naming organisms based on similarities.

Genotype vs. Phenotype

Genotype refers to the genetic makeup of an organism, while phenotype is the observable traits.

Types of symbiotic relationships

The main types of symbiotic relationships are mutualism, commensalism, and parasitism.

What is a food chain?

A food chain illustrates the linear flow of energy through an ecosystem from primary producers to consumers and decomposers.

Photosynthesis equation

The overall equation for photosynthesis is 6CO2 + 6H2O + light energy → C6H12O6 + 6O2.

Meiosis

Meiosis is a type of cell division that produces gametes with half the number of chromosomes as the parent cell.

Function of ribosomes

Ribosomes are the sites of protein synthesis, creating polypeptide chains.

Mitosis

Mitosis is the process of cell division that results in two identical daughter cells with the same chromosome number as the parent.

Describe primary succession.

Primary succession is the series of ecological changes that occur in an area where no ecosystem previously existed, requiring soil accumulation.

Definition of homeostasis

Homeostasis is the ability of a cell to maintain a stable internal environment despite external changes.

Adaptations

Adaptations are inherited traits that enhance an organism's ability to survive and reproduce in its environment.

What is a niche in ecology?

A niche refers to the role a species plays in its community, including its diet, habitat, and its impact on energy flow.

Define exponential growth in populations.

Exponential growth is a J-curve pattern where population growth accelerates as conditions remain ideal.

What are pioneer species?

Pioneer species are the first organisms to populate an area during primary succession, such as lichens and mosses.

What is nitrogen fixation?

Nitrogen fixation is the process by which bacteria convert atmospheric nitrogen into forms usable by plants.

Explain secondary succession.

Secondary succession occurs in areas where an ecosystem has been disturbed but soil and some organisms remain, leading to faster recovery than primary succession.

What is the significance of adaptations in organisms?

Adaptations are traits that enhance an organism's survival and reproductive success in its environment.

Define trophic level.

A trophic level is a position in a food chain or food web, representing the flow of energy from producers to consumers.

What are the two main types of cell division?

Mitosis produces identical somatic cells, while meiosis produces gametes with half the number of chromosomes.

What is the significance of genetic variation in populations?

Genetic variation is crucial for a population's adaptability and survival in changing environments.

What is carrying capacity in ecology?

Carrying capacity is the maximum stable population size that an environment can support over time.

What is the role of decomposers in an ecosystem?

Decomposers break down dead organic matter, recycling nutrients back into the ecosystem.

What is the significance of enzymes in biological processes?

Enzymes are catalysts that speed up chemical reactions without being consumed, facilitating biological processes.

Describe the concept of natural selection.

Natural selection is the process by which organisms with favorable traits are more likely to survive and reproduce, leading to evolutionary changes.

What is the carbon cycle?

The carbon cycle is the continuous movement of carbon through the atmosphere, oceans, land, and living organisms.

What is the process of photosynthesis?

Photosynthesis is the process by which plants convert light energy into chemical energy, producing glucose and oxygen.

What is the function of chloroplasts?

Chloroplasts capture solar energy for photosynthesis, converting it into chemical energy.

What are Pioneer Species?

The first organisms to colonize previously uninhabited land in primary succession.

What is logistic growth in population dynamics?

Logistic growth is an S-curve pattern where population growth slows as resources become limited.

What is the climax community?

A climax community is a stable and mature ecosystem where populations of plants and animals exist in balance.

What are density-dependent limiting factors?

Density-dependent limiting factors are influences on population growth that intensify as the population density increases, such as predation and competition.

What is the energy transfer efficiency between trophic levels?

The total energy transfer from one trophic level to the next is approximately 10%.

Define biogeochemical cycles.

Biogeochemical cycles are pathways through which essential elements move through the environment, involving both biotic and abiotic components.

What is the difference between a carnivore and an omnivore?

Carnivores eat other animals, while omnivores eat both plants and animals.

What is the role of ribosomes in cells?

Ribosomes are the sites of protein synthesis, translating messenger RNA into polypeptide chains.

What are abiotic factors in an ecosystem?

Abiotic factors are the nonliving components of an ecosystem, such as temperature, water, and soil.

Define homeostasis in living organisms.

Homeostasis is the ability of an organism to maintain a stable internal environment despite external changes.

What is the function of the Golgi apparatus?

The Golgi apparatus modifies, sorts, and ships proteins and lipids for secretion or use within the cell.

What are Density-dependent limiting factors?

Factors that affect population growth based on population density, such as competition and predation.

What is speciation?

Speciation is the formation of new species as a result of evolutionary processes such as geographic isolation.

What is cellular respiration?

Cellular respiration is the process by which organisms convert glucose and oxygen into energy, carbon dioxide, and water.

Define Commensalism in ecology.

A relationship where one species benefits while the other is not affected.

What is Coevolution?

The process where two species evolve in response to each other over time.

What is the role of the plasma membrane?

The plasma membrane controls the movement of materials into and out of the cell, maintaining homeostasis.

What is Primary Succession?

The development of an ecosystem in an area where no soil exists, starting with pioneer species.

What is the role of Decomposers in an ecosystem?

Decomposers break down dead organisms, recycling nutrients back into the ecosystem.

What is a Climax Community?

A stable and mature ecological community that undergoes little change in species composition.

Define Adaptations in biology.

Genetically coded traits that enhance an organism's survival and reproduction in its environment.

What is Natural Selection?

A mechanism explaining how organisms with favorable traits survive and reproduce more successfully.

Define the Energy Pyramid in ecosystems.

A graphical representation showing energy transfer between trophic levels, with only about 10% efficiency.

What is the definition of a Niche?

The specific role or function of a species within an ecosystem, including its habitat and interactions.

What is Cellular Respiration?

The metabolic process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

What is the definition of Symbiosis?

A close relationship between two organisms of different species, where at least one benefits.

What is Secondary Succession?

The recovery of an ecosystem after a disturbance, where soil is already present.

What are Trophic Levels?

Levels in a food chain that categorize organisms based on their role in energy transfer.

Explain Convergent Evolution.

Unrelated species independently evolve similar traits due to adapting to similar environments.

What is the significance of Fossils in evolution?

Fossils provide evidence for evolution and can be dated to show changes over time.

What is Relative Dating in geology?

A method used to determine the approximate age of fossils based on their position in sedimentary rock layers.

What are the two main types of Cell Division?

Mitosis, for somatic cell division, and Meiosis, for gamete formation.

What is the difference between a Carnivore and an Omnivore?

Carnivores primarily eat other animals, while omnivores eat both plants and animals.

Define Mutualism in ecology.

A relationship where both species benefit from the interaction.

What is Speciation?

The formation of a new species through mechanisms like geographical, temporal, or behavioral isolation.

What is the difference between Exponential and Logistic Growth?

Exponential growth is unrestricted population increase, while logistic growth accounts for resource limitations.

Explain the significance of Genetic Variation.

Genetic variation is crucial for the adaptability and survival of populations in changing environments.

What is Absolute Dating?

A technique used to determine the actual age of fossils using methods like radiometric dating.

What is the role of the Plasma Membrane?

It controls the movement of substances into and out of the cell, maintaining homeostasis.

Define carrying capacity in ecology.

The maximum population size that an environment can sustainably support.

What is the process of Photosynthesis?

The conversion of light energy into chemical energy by plants, producing glucose and oxygen.

What is Parasitism?

A relationship where one species benefits at the expense of another, causing harm.

What is Nitrogen Fixation?

The process by which nitrogen gas is converted into ammonia or related compounds, making nitrogen available to plants.

What is the significance of Enzymes in biological processes?

Enzymes are catalysts that speed up chemical reactions without being consumed in the process.

What is the significance of the Central Dogma?

It describes the flow of genetic information from DNA to RNA to proteins, essential for cellular function.

PROKARYOTES:

Single-celled organisms that lack internal
structures surrounded by membranes. They
lack a true nucleus.
Examples:
Bacteria, Archaea

EUKARYOTES:

Single- and multicellular organisms that have cells
containing internal, membrane-bound structures.
They have a true nucleus containing the cell’s DNA.
Examples:
Plants, Animals, Fungi, Protists

All living things share these characteristics:
Require energy for life processes
Respond to stimuli in their environment
Reproduce similar offspring
Made of cells

Plasma membrane:
Controls materials entering and exiting the cell

Cell wall:
Protects and gives shape to the cell

Nucleus: contains DNA
Chloroplasts: photosynthesis
Mitochondria: energy (ATP) formation
Golgi bodies: modify, sort, ship
Ribosomes: make proteins

Maintaining balance:
Homeostasis

Biomolecule Monomer Examples:
Carbohydrates: monosaccharides
Lipids: glycerol and fatty acids
Proteins: amino acids (enzymes, antibodies, insulin)
Nucleic Acids: nucleotides

Passive transport: without energy
Osmosis: movement of water
Facilitated transport: protein helps move substance

Active transport: requires energy
Endocytosis: brings material into the cell
Exocytosis: pushes material out of the cell

Enzymes:

• Speed up reactions
  
  

• Work faster
  
  

• Are specific to substrates
  
  

Photosynthesis:

1. Light-dependent reactions
   
   

2. Calvin cycle: forms glucose
   
   

Cellular Respiration:
Produces ATP

Classification:
Based on similarities
Two-word system: binomial nomenclature
Taxonomy = science of naming and grouping
Kingdom, Phylum, Class, Order, Family, Genus, Species

DNA:
Nucleotides
RNA bases: Adenine, Uracil, Guanine, Cytosine
mRNA: carries code to ribosome
rRNA: site of protein synthesis
Transcription: DNA → RNA
Translation: RNA → Protein

Genetics:
Study of heredity
Gene versions = alleles
Homozygous = same (TT or tt)
Phenotype = physical trait
Genotype = genetic makeup
Phenotype = determined by genotype

Punnett square result:
50% black, 50% brown

Mutations:
Change in DNA sequence
Source of genetic variation

Meiosis = gametes (haploid), has crossing over
Mitosis = body cells, 1 division, daughter cells identical

DNA fingerprinting: identify people
Genetic engineering = insert DNA into bacteria
Plants get resistant traits

Reproduction:
Asexual = 2 identical cells
Sexual = genetic diversity
Genetic variation in offspring

Ecology:
Interactions with environment
Population = group of same species
Ecosystem = biotic and abiotic factors
Biosphere = Earth

Growth:
Exponential = J-curve
Logistic = S-curve
Carrying capacity = maximum stable population
Niche = organism’s role
Habitat = where it lives

Biomes:

• Tundra
  
  

• Tropical Rainforest
  
  

• Desert
  
  

• Grassland (Savanna)
  
  

• Taiga (Boreal Forest)
  
  

• Temperate Deciduous Forest
  
  

Marine Biomes:

• Open ocean
  
  

• Intertidal zone
  
  

• Estuary
  
  

Consumer Types:

• Herbivore: deer
  
  

• Carnivore: eat animals
  
  

• Omnivore: raccoon
  
  

• Decomposers: fungi, bacteria
  
  

Energy moves in a food web
Only 10% energy passed per level

Matter is recycled
Cycles:

• Water (evaporation, precipitation)
  
  

• Nitrogen (fixation by bacteria)
  
  

• Carbon
  
  

• Phosphorus (rocks → plants)
  
  

Succession:
Primary: starts with bare rock
Climax: stable population
Secondary: after disturbance, faster

Adaptations:

• Behavioral: squirrels storing food
  
  

• Structural: hawks use wings
  
  

• Physiological: snakes make venom
  
  

Plant Adaptations:

• Waxy leaves = conserve water
  
  

• Modified storage organs
  
  

Symbiosis = two organisms, one benefits

Evolution = change over time
Darwin = naturalist
Adaptations = help survival
Natural selection = best traits passed on
Speciation = new species
Coevolution = evolve together
Fossils = evidence
Radiometric = actual dating

Cladograms = show common ancestors
More recent = more related

Scientific Method:

• Ask Question
  
  

• Hypothesis
  
  

• Experiment
  
  

PROKARYOTES:

Single-celled organisms that lack internal
structures surrounded by membranes. They
lack a true nucleus.
Examples:
Bacteria, Archaea

EUKARYOTES:

Single- and multicellular organisms that have cells
containing internal, membrane-bound structures.
They have a true nucleus containing the cell’s DNA.
Examples:
Plants, Animals, Fungi, Protists

All living things share these characteristics:
Require energy for life processes
Respond to stimuli in their environment
Reproduce similar offspring
Made of cells

Plasma membrane:
Controls materials entering and exiting the cell

Cell wall:
Protects and gives shape to the cell

Nucleus: contains DNA
Chloroplasts: photosynthesis
Mitochondria: energy (ATP) formation
Golgi bodies: modify, sort, ship
Ribosomes: make proteins

Maintaining balance:
Homeostasis

Biomolecule Monomer Examples:
Carbohydrates: monosaccharides
Lipids: glycerol and fatty acids
Proteins: amino acids (enzymes, antibodies, insulin)
Nucleic Acids: nucleotides

Passive transport: without energy
Osmosis: movement of water
Facilitated transport: protein helps move substance

Active transport: requires energy
Endocytosis: brings material into the cell
Exocytosis: pushes material out of the cell

Enzymes:

• Speed up reactions

• Work faster

• Are specific to substrates

Photosynthesis:

1. Light-dependent reactions

2. Calvin cycle: forms glucose

Cellular Respiration:
Produces ATP

Classification:
Based on similarities
Two-word system: binomial nomenclature
Taxonomy = science of naming and grouping
Kingdom, Phylum, Class, Order, Family, Genus, Species

DNA:
Nucleotides
RNA bases: Adenine, Uracil, Guanine, Cytosine
mRNA: carries code to ribosome
rRNA: site of protein synthesis
Transcription: DNA → RNA
Translation: RNA → Protein

Genetics:
Study of heredity
Gene versions = alleles
Homozygous = same (TT or tt)
Phenotype = physical trait
Genotype = genetic makeup
Phenotype = determined by genotype

Punnett square result:
50% black, 50% brown

Mutations:
Change in DNA sequence
Source of genetic variation

Meiosis = gametes (haploid), has crossing over
Mitosis = body cells, 1 division, daughter cells identical

DNA fingerprinting: identify people
Genetic engineering = insert DNA into bacteria
Plants get resistant traits

Reproduction:
Asexual = 2 identical cells
Sexual = genetic diversity
Genetic variation in offspring

Ecology:
Interactions with environment
Population = group of same species
Ecosystem = biotic and abiotic factors
Biosphere = Earth

Growth:
Exponential = J-curve
Logistic = S-curve
Carrying capacity = maximum stable population
Niche = organism’s role
Habitat = where it lives

Biomes:

• Tundra

• Tropical Rainforest

• Desert

• Grassland (Savanna)

• Taiga (Boreal Forest)

• Temperate Deciduous Forest

Marine Biomes:

• Open ocean

• Intertidal zone

• Estuary

Consumer Types:

• Herbivore: deer

• Carnivore: eat animals

• Omnivore: raccoon

• Decomposers: fungi, bacteria

Energy moves in a food web
Only 10% energy passed per level

Matter is recycled
Cycles:

• Water (evaporation, precipitation)

• Nitrogen (fixation by bacteria)

• Carbon

• Phosphorus (rocks → plants)

Succession:
Primary: starts with bare rock
Climax: stable population
Secondary: after disturbance, faster

Adaptations:

• Behavioral: squirrels storing food

• Structural: hawks use wings

• Physiological: snakes make venom

Plant Adaptations:

• Waxy leaves = conserve water

• Modified storage organs

Symbiosis = two organisms, one benefits

Evolution = change over time
Darwin = naturalist
Adaptations = help survival
Natural selection = best traits passed on
Speciation = new species
Coevolution = evolve together
Fossils = evidence
Radiometric = actual dating

Cladograms = show common ancestors
More recent = more related

Scientific Method:

• Ask Question

• Hypothesis

• Experiment

• Analyze data

• Conclusion

Controlled experiment = change 1 variable
Keep others constant

Metric Conversions:

1. 3.0 m = 300 cm

2. 1,500 mL = 1.5 L

3. 35 cg = 0.35 Dg

4. 0.05 m = 50 mm

5. 2 KL = 2000 L

Characteristics of Living Things

All living things, or organisms, share characteristics such as:

• Requiring energy to carry out life processes.

• Using energy to maintain homeostasis.

• Responding to stimuli in their environment.

• Reproducing similar offspring, passing genetic information.

• Being made of cells.

Eukaryotes have membrane-bound structures, including:

• Nucleus: Contains DNA, which controls cellular function.

• Chloroplasts: Capture solar energy for photosynthesis.

• Golgi bodies: Modify, sort, and ship proteins and lipids.

• Mitochondria: Power formation.

• Ribosomes: Synthesis of polypeptide chains (proteins).

Eukaryotes vs. Prokaryotes

• Eukaryotes: Single- and multicellular organisms with membrane-bound structures and a true nucleus containing DNA.

• Prokaryotes: Single-celled organisms lacking internal membrane-bound structures and a true nucleus.

  • Example: Bacteria

Cell Boundaries and Transport

Living cells maintain a balance between materials entering and exiting the cell, called homeostasis. Cells control internal concentrations of water, glucose, and other nutrients while eliminating cellular wastes.

• Plasma (cell) membrane: Flexible boundary that controls the movement of materials into and out of the cell, maintaining chemical balance.

• Cell wall: Thicker, inflexible boundary outside the plasma membrane that protects the cell and gives it shape (found in plants, fungi, most bacteria, and some protists).

Facilitated transport occurs when a transport protein molecule embedded in the plasma membrane transports a substance across the membrane by means of diffusion.

Biomolecules and Monomers

Cell Transport Mechanisms

• Active transport: Requires energy to move materials across cell membranes.

• Endocytosis: Cell surrounds and takes in material from its environment.

• Exocytosis: Materials exit the cell.

• Passive transport: Does not require the cell’s energy.

  • Diffusion: Movement of substances from high to low concentration.

  • Osmosis: Diffusion of water molecules through a selectively permeable membrane from high to low water concentration.

Enzymes

Enzymes are catalytic molecules that speed up specific reactions without being used up. Enzymes are proteins with four special features:

1. They only speed up processes that would occur on their own.

2. Enzymes are not permanently altered or used up in reactions.

3. The same enzyme works for forward and reverse reactions.

4. Each enzyme is highly specific about its substrate.

Photosynthesis and Cellular Respiration 🔄

Once plants use light energy to form carbohydrates, consumers can use this carbohydrate energy through cellular respiration.

Characteristics of Kingdoms

Photosynthesis

• Light reaction: Photo part of photosynthesis.

• Calvin cycle: Synthesis part of photosynthesis.

6CO2+6H2O+energy from sunlight→C6H12O6+6O26CO2​+6H2​O+energy from sunlight→C6​H12​O6​+6O2​

Cellular Respiration

C6H12O6+6O2→6CO2+6H2O+energyC6​H12​O6​+6O2​→6CO2​+6H2​O+energy

Taxonomy and Classification 🗂

Classification is the grouping of objects based on similarities.

• Aristotle classified living things into plants and animals.

• Taxonomy is the science of grouping and naming organisms. A taxonomist studies internal/external structures, chemical makeup, and evolutionary relationships.

• Linnaeus developed binomial nomenclature, a two-word system to identify species.

  • Genus (capitalized) + species (lowercase)

  • Example: Quercus alba (white oak)

Two Main Reactions of Photosynthesis

1. Light-dependent reactions split water molecules, providing hydrogen and energy for the Calvin cycle. Oxygen is released.

2. Calvin cycle forms simple carbohydrates using carbon dioxide and hydrogen from water.

Levels of Classification

Genetics 🧬

Genetics is the study of heredity, the passing on of characteristics from parents to offspring (traits).

• Genes are located on chromosomes and exist in alternative forms called alleles.

DNA and RNA

Nucleic acids are made up of subunits called nucleotides.

• DNA:

  • Sugar: deoxyribose

  • Bases: Adenine (A), Guanine (G), Cytosine (C), Thymine (T)

  • Double-stranded

  • A-T, G-C

• RNA:

  • Sugar: ribose

  • Bases: Adenine (A), Uracil (U), Guanine (G), Cytosine (C)

  • Single-stranded

Punnett Square Example

In rabbits, black fur (B) is dominant over brown fur (b). If one parent rabbit is heterozygous (Bb) and the other is homozygous brown (bb):

• 50% of offspring would be black (Bb).

• 50% would be brown (bb).

Probability of brown fur is 50% (2 out of 4).

Central Dogma

• Replication: DNA -> DNA

• Transcription: DNA -> RNA

• Translation: RNA -> Amino acids (proteins)

Types of RNA

• mRNA (messenger RNA): Carries code from genes to ribosomes.

• rRNA (ribosomal RNA): Combines with protein to form ribosomes; site of protein synthesis.

• tRNA (transfer RNA): Carries amino acids to ribosome.

Genetic Terminology

• Genotype: Genetic make-up (BB, Bb, bb)

• Phenotype: Physical trait (blue eyes)

• Dominant: Trait shows up in phenotype (AA or Aa)

• Recessive: Trait only shows up if homozygous (aa)

• Homozygous: Same (TT or tt)

• Heterozygous: Different (Tt)

Mutations

• Mutations are a source of genetic variation in a population!

• DNA mutations: Change in the DNA sequence.

  • Base-pair substitutions: One base is substituted for another.

  • Frameshift: Base pairs are inserted or deleted, resulting in a different amino acid.

• The phenotype is determined by the genotype!

Mendel's Contributions

Gregor Mendel successfully predicted how traits are carried from one generation to the next using pea plants. He identified dominant and recessive traits (genes).

Reproduction 👶

Meiosis produces gametes with half the number of chromosomes (haploid). Meiosis creates genetic diversity through crossing over. Mitosis creates new body (somatic) cells with the whole amount of chromosomes (diploid). Mitosis has 1 division and the new daughter cell is identical to the parent cell.

Genetic Engineering & Biotechnology 🧪

Genetic engineering involves cutting and splicing DNA molecules from different species and inserting them into bacteria or other cells that replicate rapidly. An example of this is when the insulin gene is transferred into a bacterium, the bacterium will use the “recombined” genetic code to produce human insulin.

• Plant biologists have used DNA technology to produce plants with increased disease resistance, herbicide resistance, and nutritional content.

• DNA Fingerprinting is used to identify individuals (crimes, paternity, etc.)

Mitosis Stages

• Prophase - nuclear envelope breaks up

• Metaphase - chromosomes line up in middle of cell

• Anaphase - chromosomes are pulled to opposite ends of cell

• Telophase and Cytokinesis - nuclear envelopes reform and the two cells separate.

Ecology 🌎

Ecology is the scientific study of interactions between living things and their environment.

• Individual: One organism.

• Population: Group of one type of organism.

• Community: Different species living together in an area.

• Ecosystem: All abiotic (nonliving) and biotic (living) factors in an area.

• Biome: Overlapping ecosystems with similar climates.

• Biosphere: The entire living planet.

Population Dynamics

• Habitat: The place where the organism lives.

• Niche: A species' role in its community, including what it eats, where it feeds, and its impact on energy flow.

• Population Density: Number of organisms in a given area.

• Growth Rate: Change in population size (increase, decrease, or stays the same).

• Carrying Capacity: The maximum, stable population size an environment can support.

Population Growth Patterns

• Exponential growth: J-curve. As long as ideal conditions continue, as the population grows larger, the rate of growth increases.

• Logistic growth: S-curve. As the population increases, the resources that are available become limited and the growth of the population slows and begins to stabilize.

Limiting Factors

• Density-dependent:

  • Predation

  • Parasitism

• Density-independent:

  • Weather

  • Droughts/Floods

Biomes 🏞

Terrestrial Biomes

• Grassland:

  • Abiotic Factors : 14°F to 77°F , annual precipitation 25 to 75cm

  • Biotic Factors : vegetation — grasses, small plants, mosses, lichens animals — herbivores - bi son, zebra, elephant, wildebeest ; predators – wolves, lions, leopards

• Desert:

  • Abiotic Factors : from − 22°F to 100°F in cool deserts to 68°F up to 120°F deserts; annual precipitation less than 25 cm

  • Biotic Factors : vegetation — brush, cacti, small plants animals — camels, antelope, rabbits, many reptiles, arachnids

• Tundra:

  • Abiotic Factors : − 40°F to 50°F , annual precipitation is less than 25 cm, windy, permafrost.

  • Biotic Factors : vegetation — nearly treeless, mainl y grasses and lichens animals — arctic hare, lemming, Arctic fox, snowy owl

• Boreal Forest:

  • Abiotic Factors : - 22°F to 68°F , annual precipitation 30 to 50 cm, soil thaws completely in summer

  • Biotic Factors : vegetation — coniferous trees, ferns, mosses, mushrooms animals — snowshoe hare, timber wolf, weasel, black bear, woodpe cker

• Tropical Rainforest:

  • Abiotic Fact ors : 68°F to 86°F, annual precipitation is greater than 200 cm

  • Biotic Factors : vegetation— n—b —broad - leafed evergreen trees, ferns, orchids animals — monkey, flying squirrel, birds/parrots, jaguar

• Deciduous Forest:

  • Abiotic Factors : − 22°F to 77°F , annual precipitation 75 to 125 cm

  • Biotic Factors : vegetation — sugar maple, birch, pine, oak, flowering plants, moss animals — white - tailed deer, cottontail rabbit, squirrel, raccoon

• Marine Biomes

  • Abiotic Factors : temperature change is extreme , salt and fresh water

  • Biotic Factors : algae, mosses, aquatic plants, insects, shrimp, crabs, birds

Abiotic Factors : alternating exposure to sunlight and submergence

Biotic Facto rs mussels, starfish

in hot

Energy Flow in Ecosystems ⚡

Energy cannot be recycled, so it moves through an ecosystem: sunlight -> primary producers -> consumers -> decomposers. This is called a food chain.

Energy Pyramid

Total energy transfer from one trophic level to the next is only about 10%.

Food Webs

• Overlapping food chains create a food web.

• Arrows show the flow of energy.

• Water cycles from atmosphere to land (precipitation) and back to the atmosphere (evaporation).

• Bacteria perform Nitrogen Fixation so the plants can use the nitrogen.

• All living organisms are based on the carbon atom.

• Phosphorus is found in the soil and then taken up by plants and animals.

Trophic Levels