Biology Top 101

Organic Compounds

• All living things are made of organic compounds.
• Contain the element Carbon
• Carbohydrates, Proteins, Lipids, Nucleic Acids

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Carbohydrates

• Monomer- monosaccharide
• Function- energy source and structure
• Tests: glucose-Benedicts

starch- Iodine

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fructose

• Ex. Cellulose, glycogen, starch

Lipids

• Made of fatty acids and glycerol
• Function- energy storage and insulation
• Tests: brown paper test
• Examples: fats and steroids

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Lipid vs. water

Nucleic Acids

• Monomer- nucleotide
• Function- carry genetic information
• Ex. DNA and RNA

Proteins�

• Monomer- amino acids
• Function- building and repairing cells, communication, transport, and regulation
• Tests- Biurets
• Examples: enzymes,

hemoglobin

Enzymes

• Catalysts in living things
• Specific to a particular substrate
• Reusable
• Affected by temperature and pH

Cells

Prokaryotes

• Simple, no membrane bound organelles
• Bacteria only
• One circular chromosome
• Includes: chromosome, ribosomes, and plasma membrane

Eukaryotes

• Membrane bound organelles
• Plants and Animals
• True nucleus containing chromosomes

Nucleus

• “Control Center”
• Contains chromosomes

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Mitochondria�Singular: Mitochondrion

• “Powerhouse” of the cell
• Produces energy in the form of ATP
• Site of Aerobic respiration

Chloroplast

• Site of photosynthesis
• Plant cells ONLY
• Contains the pigment chlorophyll

Vacuole

• Storage of excess materials
• Plant cells usually contain one large vacuole

Ribosomes

• Proteins are synthesized
• Found in both prokaryotes and eukaryotes

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Plasma Membrane�aka: Cell Membrane

• Surrounds the cell
• Regulates what enters/leaves the cell
• Helps maintain homeostasis
• Made of phospholipids with embedded proteins

Cell Wall

• Plant cells ONLY
• Surrounds cell and provides support and protection.
• Made of cellulose

Eukaryotes

Plant

• Cell wall
• Chloroplast
• Large central vacuole

Animal

Cell Organization

Cell

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Tissue

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Organ

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Organ System

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Individual organism

Cell Specialization

• cells develop to perform different functions
• Regulated by genes

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Cell to Cell Communication

• Chemical Signals (hormones) can be sent from one cell to another
• Receptor proteins on the plasma membrane receive the signal

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Diffusion

• Form of passive transport (NO ENERGY NEEDED) across a membrane
• Solutes move from high concentration to low concentration

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Osmosis

• Diffusion of water (also passive transport)

Active Transport

• Particles moving against the concentration gradient which REQUIRES ENERGY (ATP)
• Low concentration to high concentration

ATP

• Energy storing molecule
• Can be used for quick energy by the cell
• Energy is stored in the phosphate bonds

Photosynthesis

• Water and Carbon Dioxide used to produce Glucose and Oxygen
• H2O+CO2→C6H12O6+O2
• Occurs in the chloroplast

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Aerobic Respiration

• Used to release energy (ATP) for cellular use
• C6H12O6+O2→H2O+CO2
• Occurs in the mitochondria

Anaerobic Respiration�aka Fermentation

• Does not require Oxygen
• also used to release energy, but not as efficient as aerobic respiration (less ATP)
• Products include CO2 and lactic acid or alcohol
• Two Types: Alcoholic Fermentation and Lactic Acid Fermentation

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Autotroph vs. Heterotroph

• Obtain energy from the environment
• Photosynthesis or chemosynthesis
• “Producers”

• Obtain energy from other living things
• “Consumers”

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DNA / RNA

• Carry genetic information
• Made of a chain of nucleotides
• Nucleotides contain a sugar, phosphate, and a nitrogen base

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DNA / RNA

DNA

• Double stranded
• “Double Helix”
• Four base pairs: ATGC
• Sugar is Deoxyribose
• Found in nucleus

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RNA

• Single stranded
• Four base pairs: AUCG
• Sugar is Ribose

Base Pair Rule

• In DNA,

Adenine always pairs with Thymine, and

Guanine always pairs with Cytosine

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Replication

• Making of an identical strand of DNA
• “semi” conservative

Central Dogma

DNA → RNA → protein → trait

Transcription

• DNA→mRNA
• Occurs in nucleus
• Complementary mRNA strand is produced from a segment of DNA

Translation

• Connects amino acids in the correct order to make a protein
• Occurs in the cytoplasm within the ribosomes

A- amino acid

B- tRNA

C- anticodon

D- codon

E- mRNA

F- Ribosome

G-polypeptide

Codon

• Sequence of three mRNA nucleotides that code for an amino acid

Mutations

• Change in DNA code
• May cause a change in protein produced
• NOT always harmful

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Sickle Cell Mutation

Mitosis

• Cell division
• Produces two identical diploid daughter cells
• Occurs in body cells to grow and repair

Cancer

• Error in cell growth with causes uncontrolled cell growth
• Has environment and genetic variables

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Meiosis

• Cell division
• Produces four different haploid daughter cells (gametes)
• Occurs in sex cells to form gametes

Crossing Over

• Homologous chromosomes exchange parts of their DNA
• Creates variation in gametes

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Nondisjunction

• Homologous chromosomes fail to separate during meiosis
• Can lead to Down Syndrome, Turners Syndrome, and Klinefelters Syndrome

Asexual vs. Sexual �Reproduction

Asexual

• One parent
• Identical offspring
• Variation only thru mutations
• Examples: budding, fragmentation, fission

Sexual

• Two parents
• Offspring different from parents
• More variation
• Fertilization (fusion of gametes)

Inheritance

• Traits are specific characteristics inherited from parents
• Genes are the factors that determine traits
• The different forms of a gene are called alleles

Dominant/Recessive Alleles

• Dominant alleles are expressed, if present, and recessive are hidden

Genotype�actual alleles an individual has for a trait

Homozygous

• Both alleles are the same
• Ex. BB or bb

Heterozygous

• Both alleles are different
• Ex. Bb

Phenotype

• The actual characteristic displayed by the individual (ex. brown eyes, Hemophiliac)

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Incomplete Dominance

• Heterozygote shows a blending of the dominant and recessive phenotypes

Codominance

• Heterozygote expresses BOTH dominant and recessive traits
• Ex. Roan animals

Polygenic Traits

• Traits are influenced by more than one gene
• Ex. skin color

Multiple Alleles

• More than two alleles for a trait (an individual still only inherits two)
• Ex. Blood Type (I^A,I^B, i)

type A = I^AI^A or I^Ai

type B = I^BI^B or I^Bi

type AB= I^AI^B

type O = ii

Sex Linked Traits

• Sex Chromosomes
• Female = XX
• Male = XY
• Sex linked traits are carried on the X chromosome
• Ex. Hemophilia, red-green colorblindness

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Test Cross

• used to determine the phenotype of an unknown dominant individual
• uses a homozygous recessive individual as the “test”

Pedigree

• similar to a family tree
• Shows pattern of inheritance of a specific trait through a family

Karyotype

• Picture of someone's chromosomes
• Can detect chromosomal disorders

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Ex. Down Syndrome, Klinefelter’s Syndrome, and Turners Syndrome

Human Genome Project

• Sequencing of human DNA
• Being used to develop gene therapies

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Gel Electrophoresis

• Technique used to separate molecules (DNA or proteins) based on their size
• Sometimes called a DNA fingerprint
• Used to analyze and compare DNA

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Recombinant DNA

• Cell with DNA from another source
• Bacteria used to produce human insulin
• Human gene inserted into bacterial plasmid

Transgenic Organism

• An organism with a gene from another source
• used to improve food supply, research, and healthcare

Clone

• An organism made from one cell of another organism
• A genetically identical copy

Origin of Life

• Abiotic earth LACKED Oxygen
• Early organims anaerobic prokaryotes

Miller and Urey

Experiment recreating

The abiotic atomospere

Endosymbiotic Theory

• Eukaryotic cells evolved from prokaryotes
• Early prokaryotes engulfed other prokaryotes and developed symbiotic relationships
• Evidence includes mitochondria and chloroplast have prokaryotic type DNA

Abiogenesis

• Living from non-living or spontaneous generation
• Disproved by Redi and Pasteur’s experiments

Biogenesis

• Living from Living

Natural Selection

• Theory of Evolution
• Fit organisms survive, reproduce, and pass on traits

Requirements:

• Variation
• Competition

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Adaptations

• Trait that increases survival
• For Example,
• Beaks that make it easier to eat insects
• Bright flowers to attract pollinators
• Vascular tissue in plants to adapt to life on land

Evidence for Evolution

• Fossil Record
• Biochemical Similarities
• Shared anatomical structures

Speciation

• Evolution of a new species
• must be isolation between populations

Antibiotic and Pesticide Resistance

• Populations will eventually become resistant to pesticides and antibiotics with overuse

Coevolution

• Two organisms evolve in response to each other

Ex. Flowering plants and their pollinators

Binomial Nomenclature

• Two word naming system
• Scientific name
• Uses Genus and Species names
• Ex. Dogs: Canis familiaris

Dichotomous Keys

• Used to identify organisms
• Paired set of questions with two choices

Levels of Organization

Phylogenic tree

Protists

• Unicellular Eukaryotes
• Can be autotrophic or heterotrophic
• Reproduce mostly asexually

Fungi

• Multicellular eukaryotes

(yeast are the only unicellular fungi)

• Heterotrophs
• Reproduce asexually and sexually

Plants

• Multicelluar eukaryotes
• Autotrophs
• Reproduce sexually and asexually

Animals

• Multicellular eukaryotes
• Heterotrophs
• Reproduce sexually and asexually

Non Vascular Plants

• Also called Bryophytes
• No true roots or vascular tissue causing them to be small in size
• Must live in moist environments
• Reproduce with spores

Ex. Mosses, liverworts

Gymnosperms

• Non-flowering vascular plants
• Reproduce with

cones that contain seeds

• Ex. Conifers (pine trees)

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Angiosperms

• Flowering vascular plants
• Flower is main reproductive organ
• Seeds are enclosed within a fruit
• Ex. Deciduous plants

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Insects

• Transport through open circulatory system
• Exchange gases through spiracles and tracheal tubes
• Most reproduce sexually with internal fertilization
• Develop through metamorphosis

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Annelids�(segmented worms)

• Transport through closed circulatory system
• Exchange gases through moist skin
• Reproduce asexually and sexually with internal fertilization

Amphibians

• Transport through a closed circulatory system involving a three chambered heart
• Gas exchange in young with gills, adults lungs and moist skin
• Reproduce sexually with external fertilization
• Develop through metamorphosis

Mammals

• Transport though closed circulatory system involving a four chambered heart
• Gas exchange through lungs
• Reproduce sexually with internal fertilization
• Young develop in a uterus and exchange nutrients and oxygen through the placenta (placental mammals)

Viruses

• Not considered living things
• Pathogens that can mutate to resist vaccines
• Ex. HIV, Influenza,

Smallpox

Genetic Disorders and the Environment

• Many diseases have both genetic and environmental factors
• Ex. Cancer, diabetes, PKU

Immune Response

B-cells

• Fight antigens in body fluids
• B-cells make antibodies
• Make memory cells after exposure to antigen

T-cells

• Fight pathogens inside living cells
• May help B-cells to make antibodies
• Make memory cells after exposure to pathogen

Immunity

Passive Immunity

• Antibodies are introduced into the body
• Short term
• Such as mother transfers antibodies to infant through breast feeding

Active Immunity

• Antibodies are acquired when an immune response is activated in the body
• Long term
• Ex. Vaccines are weak/dead antigens that are introduced to the body

Parasites

• Lives on or within a host
• Benefits while causing harm to the host
• Ex. Plasmodium causes malaria (genetic influence- carriers of sickle cell are resistant to malaria)

Toxins

• Chemical that causes harm to the body
• Can be man-made or produced by microorganisms
• Ex. Mercury and Lead

Ecosystems

• Collection of abiotic (nonlivng) and biotic (living) factors in an area
• Together they influence growth, survival, and productivity of an organism

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Symbiotic Relationships

• Relationship between two organisms in which one benefits
• Types:
• Mutualism (+,+)
• Parasitism (+,-)
• Commensalism (+, o)

Predation

• Predator eats prey
• Evolve in response to one another

Carrying Capacity

• Maximum number of individuals that an ecosystem can support
• Limiting factors:
• Food availability
• Competition
• Disease
• Predation
• Natural Disasters

Carbon Cycle

Trophic Levels

• Steps in a food chain/web
• Energy passes from one organism to another
• About 10% of the energy at one level passes to the next

Human Population

• Growth= birth rate-death rate

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Human Impacts

Positive

• Reforestation
• Cover Cropping
• Recycling
• Sustainable practice

Negative

• Acid Rain
• Deforestation
• Habitat Destruction
• Invasive Species
• Ozone depletion from the release of CFCs

Global Warming

• Increase in the average temperature of the earth
• Caused by the release of too much CO2 into the atmosphere which amplifies the greenhouse effect
• Burning of fossil fuels, volcanic eruptions

Bioaccumulation

• An increase in environmental toxins at higher tropic levels
• Ex. DDT and birds of prey

Innate Behavior

• Behaviors an animal is born with
• Includes suckling, migration, hibernation
• Ex. weaving of spider webs

Learned Behavior

• Behavior an animal acquires during its lifetime
• Includes
• Habituation
• Conditioning
• Trial and error

Social Behavior

• Communication between individuals of the same species
• Can be courtship, territorial or chemical (pheromones)