Themes in BiologyThemes in Biology

Biology- the study of all living things

Properties of Living Organisms

1. Cellular structure and function

cell: basic unit of structure and function of organisms, capable of all life functions

- covered by membranes

- some organisms are unicellular or multicellular

2. Reproduction - process by which organisms make more of the same organism

- essential for life since no organism lives forever

3. Metabolism- sum of all chemical reactions in an organism 3. Metabolism- sum of all chemical reactions in an organism

- sun: main source of energy for all organisms to fuel - sun: main source of energy for all organisms to fuel chemical reactionschemical reactions

Ex: plants capture suns energy and make glucoseEx: plants capture suns energy and make glucose which we eatwhich we eat

4. Maintain homeostasis - constant internal environment in an organism4. Maintain homeostasis - constant internal environment in an organism

- organisms must respond to external environment to - organisms must respond to external environment to survive survive

Ex: arctic seals- blubber Ex: arctic seals- blubber

cactus- heavy waterproof layercactus- heavy waterproof layer

5. Heredity – passing of traits from parent to offspring5. Heredity – passing of traits from parent to offspring - controlled by genes (proteins) on DNA- controlled by genes (proteins) on DNA

- can be affected by mutations- can be affected by mutations

Mutations – change in the DNA which can be harmful or beneficial Mutations – change in the DNA which can be harmful or beneficial

Ex: sickle cell anemiaEx: sickle cell anemiaBad- rbc do not carry oxygen properlyBad- rbc do not carry oxygen properlyGood- give resistance to malariaGood- give resistance to malaria

sex cell mutations are passed on to offspringsex cell mutations are passed on to offspringautosomal mutations are not passed to offspringautosomal mutations are not passed to offspring

6. Evolution – gradual change in a species over a period of time6. Evolution – gradual change in a species over a period of time

Species: group of genetically similar organisms that can produce Species: group of genetically similar organisms that can produce fertile fertile

offspringoffspring

Darwin- said evolution occurred through natural selectionDarwin- said evolution occurred through natural selection - Organisms with favorable genes survived, reproduced, - Organisms with favorable genes survived, reproduced,

and passed favorable genes to offspring.and passed favorable genes to offspring.

7. Interdependence – organisms dependence on each other within an environment7. Interdependence – organisms dependence on each other within an environment

Purposes of BiologyPurposes of Biology

To solve real world problems:To solve real world problems:

A. Studying ecosystemsA. Studying ecosystems

B. Genetically engineered cropsB. Genetically engineered crops

C. Help fight diseasesC. Help fight diseases- AIDS- AIDS- Cancer- Cancer- Cystic fibrosis- Cystic fibrosis

The Scientific MethodThe Scientific Method

Steps Steps

1. Make observations and 1. Make observations and

ask a questionask a question

2. Form a hypothesis 2. Form a hypothesis

(educated guess based on (educated guess based on

what is already known)what is already known)

- prediction:- prediction:

expected outcome from expected outcome from the test assuming the the test assuming the hypothesis is correct hypothesis is correct

3. Test the hypothesis thru 3. Test the hypothesis thru experimentation experimentation

- controlled experiment- controlled experiment

A. control group: A. control group: “ “normal condition”normal condition”

- receives no experimental - receives no experimental treatment or change in treatment or change in condition condition

B. experimental group: B. experimental group: “ “test group”test group”

- variable/ experimental - variable/ experimental factor factor being tested for being tested for

a. independent variable: a. independent variable: factor being varied factor being varied

b. dependant variable: b. dependant variable: factor being measured factor being measured

4. Collect and analyze data4. Collect and analyze data - use charts, tables, - use charts, tables, observations observations

5. Draw conclusions 5. Draw conclusions (formation of a theory)(formation of a theory)

- can support or reject - can support or reject hypothesis hypothesis

- can be disproven - can be disproven through further through further experimentation experimentation

6. Share results or retest 6. Share results or retest - publish data in scientific - publish data in scientific journals journals

Representing Data GraphicallyRepresenting Data GraphicallyCharts/GraphsCharts/Graphs

There are three basic components to most charts/graphs: There are three basic components to most charts/graphs:

• Labels- defines the data: Labels- defines the data: - title, axis titles and labels, legends defining - title, axis titles and labels, legends defining

separate data seriesseparate data series

• Scales- define the range of the Y and the X axisScales- define the range of the Y and the X axis

• Graphical elements- represent the dataGraphical elements- represent the data- bars in bar charts- bars in bar charts- lines in times series plot- lines in times series plot- points in scatter plots- points in scatter plots- slices of a pie chart- slices of a pie chart

Pie ChartsPie Charts

Bar GraphsBar Graphs

Line GraphsLine Graphs

School System EnrollmentSchool System Enrollment

Scatter Plots (x,y)Scatter Plots (x,y)

                               

                                                                                               

Scatter Plots (x,y)Scatter Plots (x,y)Rules for Scatterplots (shows relationship between variables)Rules for Scatterplots (shows relationship between variables)

• Use two interval-level variables (x and y)Use two interval-level variables (x and y)

• Fully define the variables with the axis titlesFully define the variables with the axis titles

• Chart title should identify the two variables and the cases (e.g., cities Chart title should identify the two variables and the cases (e.g., cities or states) or states)

• X axis: independent variable (cause)X axis: independent variable (cause) Y axis: dependent variable (result)Y axis: dependent variable (result)

• Scale the axes to maximize the use of the plot area for displaying the Scale the axes to maximize the use of the plot area for displaying the data points       data points       

• Use same interval measurements on each axisUse same interval measurements on each axis

• Do NOT connect dots, use a trend lineDo NOT connect dots, use a trend line

Scatter Plot Trend LinesScatter Plot Trend Lines

NEGATIVE NEGATIVE

indirect indirect

relationship relationship

(+, -) (+, -)

NULL POSITIVE NULL POSITIVE

no no direct direct

relationshiprelationship relationship relationship

(0,0) (+, +)(0,0) (+, +)

TheoryTheory

- Explanation based on a set of related hypotheses that - Explanation based on a set of related hypotheses that have been tested and confirmed many times but can have been tested and confirmed many times but can be broken.be broken.

- Theories unite and explain a broad range of Theories unite and explain a broad range of observationsobservations

- Scientific theories are generally accepted as scientific - Scientific theories are generally accepted as scientific principle whereas to the general public, theories are principle whereas to the general public, theories are considered statements of uncertaintyconsidered statements of uncertainty

Scientific Law Scientific Law

summarizing statement that is summarizing statement that is considered fact and can not be brokenconsidered fact and can not be broken

Ex: gravityEx: gravity

Studying BehaviorStudying Behavior

• animal behavioranimal behavior:: what an animal does when interacting with its what an animal does when interacting with its environment environment

ex: humpback whale: bubble netex: humpback whale: bubble net

                           

                                                                                

               

Designing Experiments on Animal BehaviorDesigning Experiments on Animal Behavior

• Hypothesis based experimentsHypothesis based experiments• Dutch biologist Niko Tinbergen studied Dutch biologist Niko Tinbergen studied

digger waspsdigger wasps• "How does each wasp keep track of her "How does each wasp keep track of her

nests?" nests?"

Causes of BehaviorCauses of Behavior

• immediate cause:immediate cause: explanation of an explanation of an organism's behavior based on its immediate organism's behavior based on its immediate interactions with the environmentinteractions with the environment

• ultimate cause:ultimate cause: explanation of an explanation of an organism's behavior based on its organism's behavior based on its evolutionary adaptations evolutionary adaptations

Tinbergen used simple materials in his Tinbergen used simple materials in his experiment—pine cones and stones—experiment—pine cones and stones—and a simple procedure. The results led and a simple procedure. The results led him to conclude that digger wasps use a him to conclude that digger wasps use a pattern of landmarks to find their nests.pattern of landmarks to find their nests.

Types of BehaviorTypes of BehaviorIs it nature or nurture?Is it nature or nurture?

• innate behaviorinnate behavior:: behavior performed behavior performed correctly and in the same way by all correctly and in the same way by all individuals of a species, without individuals of a species, without previous experience (genetic cause)previous experience (genetic cause)

• fixed action patternfixed action pattern (FAP): (FAP): innate innate behavior that occurs as an behavior that occurs as an unchangeable sequence of actions unchangeable sequence of actions

• circadian rhythmcircadian rhythm:: rhythmic pattern of rhythmic pattern of behavior (in an animal) or biological behavior (in an animal) or biological cycle (in a plant) that follows an cycle (in a plant) that follows an approximately 24-hour natural cycle approximately 24-hour natural cycle

The graylag goose responds to an egg outside The graylag goose responds to an egg outside her nest with a set of specific actions. Even her nest with a set of specific actions. Even when the egg is removed, the goose will when the egg is removed, the goose will continue to push at the air with her beak until continue to push at the air with her beak until she completes the FAP (fixed action pattern she completes the FAP (fixed action pattern

Interaction of Genes and ExperienceInteraction of Genes and Experience

How does inheritance and experienceHow does inheritance and experience

form a particular behavior? form a particular behavior?

• Biologists mated two different Biologists mated two different

species to form a hybrid speciesspecies to form a hybrid species

• Conclusion:Conclusion: hybrid offspring could hybrid offspring could alter inherited behavior based on alter inherited behavior based on experience.experience.

•                                                                                                                                      

                      

• learning:learning: a change in an animal's behavior resulting from experience a change in an animal's behavior resulting from experience

• habituationhabituation:: type of learning in which an animal stops type of learning in which an animal stops responding to a repeated stimulus that conveys responding to a repeated stimulus that conveys little or no important information little or no important information

ex: ticking of a clock ex: ticking of a clock

• imprintingimprinting: learning that is limited to a specific time period in : learning that is limited to a specific time period in an animal's life and that is usually irreversible an animal's life and that is usually irreversible

critical learning periodcritical learning period : time period in which : time period in which imprinting takes place imprinting takes place

Lorenz: greylag goose experimentLorenz: greylag goose experiment

GroupsGroups

controlcontrol: mother rears young in nest : mother rears young in nest

experimental:experimental: Lorenz rears young in incubator Lorenz rears young in incubator

result: result:

Control group: normal imprinting, followed mother, Control group: normal imprinting, followed mother,

had normal goose relationships had normal goose relationships

Experimental group: imprinted on Lorenz, followed Experimental group: imprinted on Lorenz, followed him, him, prefered human relationships to geese prefered human relationships to geese

• ConditioningConditioning: learning that a particular stimulus or a particular : learning that a particular stimulus or a particular response is linked to a reward or punishment response is linked to a reward or punishment

• Ex: Pavlov’s dogsEx: Pavlov’s dogs

operant conditioningoperant conditioning: trial and error learning: trial and error learning

• Insight: Insight: the ability to respond appropriately to a new situation without the ability to respond appropriately to a new situation without previous experience previous experience

Social BehaviorsSocial Behaviors• Competitive BehaviorsCompetitive Behaviors (pack animals) (pack animals)

aggressive behavior:aggressive behavior: symbolic threat display or a physical symbolic threat display or a physical struggle struggle between individuals of the same species between individuals of the same species

dominance hierarchy :dominance hierarchy : ranking of individuals in a group based ranking of individuals in a group based on on aggressive behavior aggressive behavior

territorial behaviorterritorial behavior: behavior that protects territorial rights: behavior that protects territorial rights

ex: ex: chatting squirrelschatting squirrels

marking areas with urinemarking areas with urine

Social BehaviorsSocial Behaviors• courtship ritual:courtship ritual: elaborate behavior of individuals of the same species elaborate behavior of individuals of the same species

before mating before mating

ex: fanning of tail feathers by a peacock ex: fanning of tail feathers by a peacock may indicate good health may indicate good health

• communicationcommunication:: signals among animals that include sounds, odors, signals among animals that include sounds, odors, visual displays, and touches visual displays, and touches

Von Frisch and later researchers determined that the angle of a returning honeybee's "waggle dance" signals Von Frisch and later researchers determined that the angle of a returning honeybee's "waggle dance" signals the direction of the food source from the hive compared to the position of the sun the direction of the food source from the hive compared to the position of the sun

                                                       

                                                                                                                                                        

           

MeasurementMeasurement

““Eventually we will have to exchange our feet for meters”Eventually we will have to exchange our feet for meters”

MeasurementMeasurement

• System International (SI)System International (SI)

- standardized system of measurement- standardized system of measurement

- based on the number 10- based on the number 10

- France, late 1700’s- France, late 1700’s

SI PrefixesSI Prefixes