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Scientific Method Name the problem or question Form an educated guess (hypothesis) and make predictions Test your hypothesis by doing an experiment. Check and interpret (analyze) your results

Scientific Method

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Scientific Method. Name the problem or question Form an educated guess (hypothesis) and make predictions Test your hypothesis by doing an experiment. Check and interpret (analyze) your results Report your results. Scientific Method. - PowerPoint PPT Presentation

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Scientific MethodName the problem or

question

Form an educated guess (hypothesis) and make predictions

Test your hypothesis by doing an experiment.

Check and interpret (analyze) your results

Report your results.

Scientific Method• Constant – does not change in an

experiment; stays the same through all trials

• Control – “standard for comparison;” not tested

• Independent variable – factor that is being tested; what the experiment (“I”) is testing

• Dependent variable – result of the experiment; what happens because of the test

Characteristics of Life

1. Made of cells

2. Reproduce

3. Grow and Develop

4. Use energy

5. Respond to stimuli

6. Maintain Homeostasis

7. Genetic Code

Organic Molecules• Lipids: Fats, Oils, Steroids

• Smallest unit - Fatty Acid & glycerol• Test: Brown Paper Bag Test

• Proteins: Enzymes, Insulation, Help fight disease• Look for Nitrogen in the chemical formula or structure!• Smallest unit - Amino Acids & peptide bonds

• Carbohydrates: Starches and Sugars (GLUCOSE)• Main Source of Energy• Smallest unit - monosaccaride • Test: Iodine

• Nucleic Acids: DNA & RNA, Genetic / Hereditary Info. • Smallest unit - Nucleotide (sugar, phosphate, nitrogenous

bases)

Ecology Terms• Habitat- Place that an organism occupies for shelter.

Includes abiotic and biotic factors.

• Niche: Role organism plays within an ecosystem.

Community Interactions

1. Competition: organism competes for resources

2. Predation: situation where one organism captures and feeds on another

3. Symbiosis: relationship where one organism lives in close association with another.

Symbiotic Relationships1. Mutualism- Both species benefit (Flower & Bee)

2. Commensalism- One species benefits and the other is neither hurt nor harmed. (Coral and Clown Fish)

3. Parasitism- One species benefits and the other is harmed. (Tick and Dog)

Ecology Terms• Population= Same species, same area

• Community= Different species, same area

• Ecosystem= All Biotic and Abiotic parts

• Producer, Plant, Autotroph= make own food, photosynthesis

• Consumer, Heterotroph= consume other things to get energy.

– Herbivore: only plants– Carnivore: only meat– Omnivore: plants and meat– Scavenger: eat dead material– Decomposer / Bacteria or fungi: Breakdown dead organic material and

return nutrients to the soil

C3

C2

C1

Producers

10%

10%

10%

10 000energy units

1 000energy units

100energy units

10 energy units

HEAT

grass

snake

owl

Greatest number of organisms, energy and biomass (amount of living substance) is found at bottom of pyramid!

cricket

Energy Pyramids•Shows the flow of energy within an ecosystem!!

Behavior• Behavior: Way that an organism reacts to

changes in its internal and external environment.

• Stimulus: anything that makes an organism respond. EX: Light, Smell

• Response: A single specific reaction to a stimulus. EX: Reflex

• Innate Behaviors: Inherited behaviors

Innate Behaviors• Migration: movement due to seasonal changes.

• Hibernation: Response to cold to conserve energy

• Estivation: Response to heat

• Circadian Rhythm: 24-Hour Routine (day-night)

• Territoriality: Animal defends territory / Reduces Conflict; uses resources efficiently; controls size of population pheromones

• Aggressive behavior: Intimidate another animal of same species to determine dominance hierarchy.

Types of Learning1. Habituation: Reduction in a previously displayed

response habit. Ex: Horses stop reacting to traffic!

2. Conditioning: learned behavior in response to a reward or punishment training. Ex: Pavlov's Dog

3. Trial and Error: learning which involves practice.

4. Insight Learning: Learning from experience problem solving.

5. Imprinting: Animal forms a social attachment to another object at a specific time. Ducks/Birds!!

Cell Theory

All living things are composed of cells.

Cells are the basic unit of life.

New cells come from old cells.

Levels of Cellar Organization

Cells Tissues Organs Organ System

1. Cells- basic unit of living things

2. Tissues- a group of similar cells that perform a particular function.

3. Organs- groups of tissues that work together to perform a task.

4. Organ System- a group of organs that work together to perform a specific function.

Two types of cells

Prokaryotes• Smaller and Simpler• No Nucleus /

Nucleoid• Bacteria

Eukaryotes• Larger and Complex• Contain more Organelles• Nucleus• Plants, Animals, Fungi,

and Protists

Plant and Animal Cells

• Animal cell do not have a cell wall or chloroplast.

• Plant cells have a cell wall and chloroplast

Cell Organelles• Nucleus: Brain of cell (DNA)

• Cytoplasm: Houses all the cells organelles

• Ribosome: Protein Synthesis

• Vacuole: Storage

• Chloroplast: Site for Photosynthesis

• Mitochondria: Site for aerobic respiration (ATP)

• Cell Wall: Extra support & protection, cellulose.

• Cell Membrane: allows some things in and others out.

Cell Membrane/Plasma Membrane

• Phospholipid bilayer (two layers of phospholipids)– circular phosphates - hydrophillic (like water)– fatty acid tails (lipids) - hydrophobic (don’t like water)

• Transport proteins allow movement of materials in and out by active and passive transport.

• Cholesterol – keeps lipids from sticking

Homeostasis

• Homeostasis- balance between internal and external environment of cell.

Factors Affecting Homeostasis

1. Temperature

2. pH Level

3. Salt Concentrations

Types of Transport

• Passive

• Does not require ATP

• Move from high concentration to low concentration.

• Osmosis (WATER)• Diffusion (MOLECULES)

• Active

• Requires ATP

• Move from low concentration to high concentration.

• Facilitated Diffusion

Cellular Movement (OSMOSIS)

• WATER FOLLOWS THE SMALLER #!!

• DISTILLED WATER IS ALWAYS 100%!

Steps to solve problems1. If problem only contains water just follow the rule

that water follows the smaller #!2. If solute is given subtract the number from 100 to get

the amount of water. 3. Once you have the amount of water for the inside

and out, follow step one.

What is an Enzyme?

• Proteins that catalyze (speed) chemical reactions within a cell.

• LOCK AND KEY (Specific for substrate)

Factors affecting enzyme activity

1. pH

2. Temperature

Enzyme Activity

Cell Communication

Cells communicate to maintain Homeostasis!!

• Hormonal Communication - chemical message that travels through the bloodstream to a target cell or target organ.

• Neuron Communication - method that allows organisms to detect and respond to stimuli.

PARTS OF A NEURON

1. Axon - sends message

2. Dendrite- receives message

Respiration

• Aerobic

• Requires Oxygen• Mitochondria• Provides Cell with

ATP

• Anaerobic

• No Oxygen Required• Fermentation• Bacteria

2 Types of Fermentation

Alcoholic: Alcohol / Yeast

Lactic acid: Muscle Soreness

EQUATION FOREQUATION FOR RESPIRATIONRESPIRATION

CC66HH1212OO66 + +GLUCOSEGLUCOSE

6O6O22

OXYGENOXYGEN

6CO6CO22 ++

CARBON CARBON DIOXIDEDIOXIDE

6H6H22OO + +ENERGYENERGY

WATERWATER

ATPATP

Respiration in Humans = diffusion in Lungs

Oxygen goes into the lung

Carbon Dioxide leaves the lung

CO2O2

EQUATIONEQUATION FORFOR PHOTOSYNTHESISPHOTOSYNTHESIS

6CO6CO22 + + 6H6H22OO + +ENERGYENERGY CC66HH1212OO66 + + 6O6O22

CARBON CARBON DIOXIDEDIOXIDE

WATERWATER

GLUCOSEGLUCOSE

OXYGENOXYGEN

DNA• Deoxyribonucleic Acid

• Double Helical Structure (Watson and Crick)

• Deoxyribose Sugar

• Determine Traits

• Found in Nucleus

• Hydrogen Bond holds bases together.

• Covalent Bonds hold phosphates and sugars.

• Bases: GCAT

• G=C

• A=T

Hydrogen Bond Holds bases!

Covalent Bond holds sugar and phosphate!

DNA Replication

• USE BASES GCAT

• TAKES PLACE IN THE NUCLEUS

Steps1. DNA polymerase separates the original strand

of DNA. (unzips)

2. Replication begins on both strands of DNA following the rules of base pairing.

RNA

• RNA is Ribonucleic Acid

• Ribose Sugar

• Single Stranded

• Bases: GCAU

• G=C

• A=U

• Protein Synthesis

Three types of RNA

Protein Synthesis

• Process whereby DNA encodes for the production of amino acids and proteins.

• Process is divided into two parts:» Transcription: Nucleus » Translation: Ribosome

• 20 Amino Acids held by peptide bonds.

• 64 combinations for Codons

• Codons: 3 letter base sequence that codes for one amino acid. EX: AUG

TRANSCRIPTION• Nucleus• Base U is used instead of T.• mRNA is created.

TRANSLATION• Ribosome• Amino acids are brought to mRNA strand by

tRNA.• Amino acids are held together by peptide

bondsprotein.

Mitosis• Results in Diploid (2n) cells = 46 chromosomes.

– daughter cell is identical to parent cell

• Interphase is the longest of the phase DNA replication and other preparation for cell division.

• Body Cells (SOMATIC)

4 Stages: PMAT1. Prophase2. Metaphase3. Anaphase4. Telophase5. Cytokinesis

Meiosis• Sperm in Males

• Ova or Egg in Females

• 2 Cell Divisions

• Haploid Cells (n=23)

• Produces 4 total cells– 4 sperm– 1 egg & 3 smaller cells

Mitosis Meiosis

1 division2 cells 2 divisions 4 cells

Daughter cells genetically identical to parent cell & to each other

Daughter cells are genetically distinct from parent & each other

Division is equilateral

2n2n

1st division reduction 2n n

2nd division equilateral n n

Sister chromatids migrate Homologous chromosomes & sister chromosomes migrate

Occurs in somatic/body cells to reproduce body cells

Occurs in sex cells produces gametes

Diploid diploid cells Diploid haploid

No genetic variation Crossing over causes variations

Gene Mutations

• Point Mutations- mutation that affects a single nucleotide only at a specific point.

• Frame shift Mutations- mutation that shifts the reading frame of the genetic message by inserting or deleting a nucleotide.

Gene Chromosome Model

Body Cells Chromosomes Genes DNA

Genes Provide Organisms with:

1. Looks

2. Some illnesses

3. Body Structure

What is Genetic Engineering?

• Method of inserting foreign DNA into a host organism of the same or different species!!

• Known as Recombinant DNA Technology!!

• Recombinant DNA is foreign DNA!

Genetic Engineering

• Process of making changes in the DNA code of living organisms.

• Gel Electrophoresis- a procedure used to separate and DNA fragments into bands.

• Cloning- copying an organisms DNA to make an exact copy of the same organism.

DNA Fingerprinting

Identifies crime suspects

Identifies paternity

Mendel’s Work• Study of Heredity (Gregor Mendel= Pea Plants)

• Genes – chemical factors that determine traits

• Alleles – different forms of genes

• Traits – a specific characteristic, such as color or plant height, that varies form one individual to another

– Dominant traits always show up in an offspring (capital letter)– Recessive traits are masked by a dominant gene (lower case letter)

• Hybrids – The offspring of crosses between parents with different traits

Genetics• Principle of Dominance: some alleles are dominant and others

are recessive.

• Principle of Independent of Assortment- genes for different traits can segregate independently during the formation of gametes.

• Incomplete dominance- situation in which one allele is not completely dominant over another. WHITE and RED = PINK

• Codominance- situation in which both alleles of a gene contribute to the phenotype of the organism. BLACK and BLUE= BLACK & BLUE

• Multiple Alleles = having three or more traits for the same gene.

Multiple Alleles / Blood Type

• NOTE: O blood type is recessive. – O= little i

– Blood Types: A, B, AB, & O• OO = blood type O

AO = blood type ABO = blood type BAB = blood type ABAA = blood type ABB = blood type B

Genetics• Homozygous (PURE)= TT or tt (SAME)• Heterozygous (HYBRID)= Tt (Different)

• Phenotype= Physical characteristics

• Genotype= genetic makeup using alleles (Letters)

• Sex-linked Traits= genes found only on the X chromosome and not on the Y chromosome.– Males= XY– Females= XX

Monohybrid Cross

Heterozygous tall parent

T t

T t

T t

T

Heterozygous tall parent

TT Tt

Tt tt

Test Cross Always use

homozygous recessive If all offspring have

the dominant trait then the genotype is probably pure (TT x tt)

If some of the offspring show the recessive trait, then the genotype is heterozygous.(Tt x tt)

T T

T t

t

t

t

t

Tt Tt

Tt Tt

Tt tt

Tt tt

Dihybrid Cross

RY Ry rY ry

RY RRYY RRYy RrYY RrYy

Ry RRYy RRyy RrYy Rryy

rY RrYY RrYy rrYY rrYy

ry RrYy Rryy rrYy rryy

RrYy x RrYy

Patterns of InheritanceKaryotype- set of photographs of chromosomes grouped in order in pairs.

Human Karyotype= 46 chromosomes (23 pairs)

44 chromosomes= Autosomal Chromosomes2 chromosomes= Sex ChromosomesTOTAL= 46

• Results from having an extra chromosome!

• Pedigrees- Chart that shows the hereditary relationships within family a family.

Evolution• CHANGE OVER TIME (Charles Darwin)

• Found similarities with finches and tortoises

• Fossils- preserved remains of ancient organisms.

Stanley Miller’s Experiment

Re-created early Earth’s atmosphere and found Re-created early Earth’s atmosphere and found that simple organic molecules such as amino that simple organic molecules such as amino acids were present.acids were present.

Evidence of Evolution• The fossil record!

• Geographical Distribution of living Species!

• Homologous Body Structures- structures that have different mature forms but develop from the same embryonic tissues.

• Vestigial Structures- structures that serve no useful function in an organism.

• Similarities in Embryology!!

Principles of Evolution

• Adaptation - any inherited trait that increases and organisms chance of survival.

• Common Descent - all living and extinct species were derived from a common ancestor.

• Humans and Chimpanzees have the closest evolutionary (DNA) similarity!!

Principles of Evolution

• Natural Selection - Naturally in the environment (Also known as Survival of the Fittest)

• Only the strongest/Fittest species survives to pass on its traits to offspring.

Charles Darwin’s Theory of Evolution

1. Overproduction• Species produces more offspring than survive.

2. Competition– Organisms compete for limited resources

3. Survival of the Fittest• Only the strongest survive and pass on their traits to their

offspring.

4. Variations– differences among organisms that help organism survive– occur among members of the same species– Result from sexual reproduction, mutations, meiosis

4 Factors that change a gene pool1. Natural Selection: only the strongest survives and

passes on genes.2. Mutations: adds new genes to the pool to be passed

on to offspring.3. Migration: movement into and out of population.

• INTO= Adding genes• OUT= Removing genes

4. Isolation: Often causes speciation.Geographic isolation

• Barrier between population divides it / Habitat Fragmentation

• Speciation= development of a new species.

Reproductive isolation• Organisms can no longer mate / caused by

geographical isolation

Classification• Taxonomy- discipline of classifying organisms and

assigning each organism a universally accepted name. (Carolus Linnaeus)

• Binomial nomenclature- System in which each species is assigned a two part scientific name.

• Genus (Capitalized) Species (Lowercase)

Levels of Organization (general to most specific)1. Kingdom2. Phylum3. Class4. Order5. Family6. Genus7. Species

Dichotomous Key Example

KingdomsKingdom Cells Feeding Example

Monera prokaryotes Heterotroph bacteria

Fungi eukaryotes Heterotroph mushroom, mold, yeast

Protista eukaryotes Autotroph

Heterotroph

amoeba, paramecium

Plant eukaryotes Autotroph angiosperm, gymnosperm

Animal eukaryotes Heterotroph annelid, arthropod, amphibian, mammal

Plant Parts

• Root System - provides plant with water and nutrients, anchors the plant.

• Stem System - support and transport of nutrients.

• Leaf System - absorb light, gas exchange, and transpiration.

Plant Tropisms

• Tropisms – growth of a plant in response to stimuli. This is an innate behavior!!

• Positive Tropisms - Plant grows toward the stimulus.

• Negative Tropisms- Plant grows away from the stimulus.

Plant Tropisms

• Phototropism- response to light.

• Geotropism - response to gravity.

• Thigmotropism- response to touching.

Leaf Structure and Functions

• Cuticle: Waxy Layer, Protection• Epidermis: Skin, Protection• Palisade: photosynthesis• Spongy: Gas exchange• Vascular Bundle: Transport

– Xylem: Water/Minerals up– Phloem: Sugars down

• Stomata: Opening where gas exchange occurs and transpiration.

• Guard Cells: Regulate the opening and closing of the stomata.

Viruses

• Not classified in a kingdoms

• Nonliving

• Piece of nucleic acid covered by protein coat (capsid).

Capsid

Nucleic acidTail

Immunity to Disease

• Passive immunity – medicines

• Acquired immunity – B & T cells (made by body)

• B-cells – make antibodies

• T-cells – 2 types: – helpers (help B-cells make antibodies) – killers (destroy invaders)

Internal & External Factors

• Viruses (infections) – HIV, Influenza, smallpox

• Bacteria (infections) – streptococcus (strept throat)

• Parasites (mosquitoes – carry viruses)

• Toxins – lead poisoning (bioaccumulation in the food chain)

Health Factors… • Tobacco use may cause lung and/or mouth

cancer

• Exposure to the sun may increase your chance of skin cancer (negative), provides Vitamin D (positive) and Folic Acid (positive)

• Diabetes may be controlled with diet and exercise, but genetics are a major factor

• PKU diets consist of fruits, vegetables, and proteins low in phenylalanine

• Genetic disorders (down syndrome – trisomy 21)

Malaria

• Vector (transmitted by) Plasmodium parasite

• Sickle cell anemia makes a person resistant to malaria