welcome to biology 112! biology is about making observations of living things what observations can...

WELCOME TO BIOLOGY 112!

Biology is about making observations of living things

What observations can you make about this cartoon?

1

Resources on my web site:

Lectures Outlines/notes Homework/extra credit assignments Review Materials, Objectives Syllabus (link on main lecture page) Prelabs are also on my lab web site.

2

Admin:• Pass out outline of notes and syllabus• Go over syllabus

This Class is HARD!

Don’t procrastinate Try to study every night Details matter You’ll need to know all this stuff for micro &

A&P Ask me if you have questions

3

General Info FOOD: ok in lecture room (as long as it’s

quiet); NONE allowed in lab PHONES: please turn it off; if you need to

make / take a call, be respectful and go outside. Penalty if it rings a 2nd time!

IN GENERAL: be respectful of everyone in the class

4

5

Chapter 1: Why Study Biology? Biology: scientific study of life Important to study and understand life in a

scientific wayAwareness and appreciation of life Important in decisions of life Issues dealing with biology arise daily

Characteristics of Life

• What things in this picture are living?

• What things are non-living?

6

Characteristics of Life

Bacteria Is it living?

7

Characteristics of all living things What are some characteristics that are

shared by all living things but NOT by non-living things?

8

Characteristics of all living things1. CELLULAR ORGANIZATION

2. METABOLISM

3. HOMEOSTASIS

4. GROWTH

5. REPRODUCTION

6. HEREDITY

7. EVOLUTION

Today and through the term, we’ll be discussing these properties of life

9

10

1 - CELLULAR ORGANIZATION

Living things are composed of CELLS Self-contained living units Unicellular (single cell) Multicellular (many cells)

11

Cells/organisms are highly Organized

Complex function Organization is required

for function

Humans have organ and tissue systems

Even bacteria have organization

Characteristics of life2. Metabolism

All the chemical reactions involving the energy and materials acquired and converted to another form by an organism.Living Things Acquire/Use Materials and

Energy from their Environment and Convert them into useful products.

13

2 - METABOLISM Collect energy from their

environment and use it to grow and develop

Energy of sunlight – Photosynthesis Energy from other living organisms –

Cellular Respiration

Metabolism examples

14

MOVEMENT

PHOTOSYNTHESIS

Thru Metabolism Life Responds to the Environment

Energy gives the organism the ability to respond to environmental stimuli

This response involves metabolism

Many organisms have multiple senses Smell, hear, taste, touch,

and see

15

Response to Environment

Senses often different than a human’s Ultraviolet/infrared light Electrical/ultrasonic fields Magnetic fields

16

Response to Environment

Senses often different than a human’s Detection of chemicals

(flies/insects)

This response involves metabolism and may change the metabolism of the cell

17

3. Homeostasis Life Actively Maintains its Structure and its Internal Environment.

Organisms respond to env changes to keep their internal operating conditions within tolerable limits, else they …

Characteristics of life

3 - HOMEOSTASIS

Ability of an organism to keep internal environment of cell or organism relatively constant compared to outside environment

19

HOMEOSTASIS

Uses Regulation to keep the internal environment of cell or organism relatively constant compared to outside environment

Regulation and homeostasis are very similar

20

Regulation

Done in various ways. Example, we keep

our internal environment relatively constant in our glucose levels by either releasing or storing glucose.

21

-Regulation

22

ANIMAL TEMPERATURE - BEHAVIORS

PLANT CARBON DIOXIDE - STOMATA

23

4 - Growth and Development

DNA as a blueprintOrganisms grow and propagate themselvesOrganisms develop and grow in complexity

Growth and Development

24

(3) Living things grow and develop

5 - Reproduction

Living organisms reproduce or replicate themselves

25

Reproduction

26

EGG AND SPERM POLLEN, FLOWERS, SEEDS

6 - Heredity

Genetic material (DNA) is passed from parents to offspring

27

7 - Evolve

Mistakes are made in replicating DNA Causing the characteristics of a population to

change

28

4. Living Things Grow,

5. Reproduce

6. Using DNA (Heredity)

7. and have the Capacity to Change & Evolve

Last 4 Characteristics of life:

DNA -deoxyribonucleic acid ... molecule encoding for life.  DNA is inherited ... offspring from its parent(s). 

DNA ... instructions for all traits, proteins and RNA. Errors occur in replicating DNA overtime

Life has been around for 3.8 billion years ... lot of time for new variants t.... and better use their environment.

Evolution is a change in a population over time occurring mainly from mutation and natural selection.  These changes ... DNA.

In life’s hierarchy of organization, new properties emerge at each level

Life’s levels of organization define the scope of biology– Life emerges through organization of various

levels– Each level is built from one or more lower

levels– With addition of each new level, novel

properties emerge

Biosphere

Ecosystem

Community

Population

Nucleus

Cell

Tissue

Organ

OrganelleMolecule

Atom

Organism Brown pelican

Organ system

Life’s Hierarchy

Biosphere

EcosystemFlorida coast

CommunityAll organisms onthe Florida coast

PopulationGroup of brown

pelicans

Organism Brown pelican

Life’s Hierarchy

Nucleus

Nerve

Spinal cord

CellNerve cell

TissueNervous tissue

OrganBrain

OrganelleNucleus Molecule

DNA

Atom

Organism Brown pelican

Organ systemNervous system

Brain

Life’s Hierarchy

34

Organization of Life

Atoms Smallest unit of elements*

Molecules Smallest unit of compounds*

Cells Smallest unit of life

Populations The unit that changes with time

* Will be discussed in chemistry

Species vs PopulationPopulation –cats in an area

Species –all kitty cats

35

What’s a species?

A group of organisms that can interbreed and produce fertile offspring

36

37

Why “fertile offspring”?

The mulehorse-donkey

hybridCannot breed

Levels of Classification

Scientists way of making sense of over 1.8 million different types of organisms

Group similar organisms into ever bigger groups

38

39

Levels of Linnaean Hierarchy

Seven levels Add Domains for

eight

Levels of Classification

How do we classify all these organisms?

Levels of Classification

How do we classify all these organisms?

Single-celled prokaryotes

Single- or multi-celled eukaryotes

Single-celled prokaryotes

Classification: The Tree of Life The Tree of Life is based on DNA

sequence similarity

42

Evolve vs Grow

EVOLVE: Species change over generations

GROW: Individuals change over organism’s lifespan

43

Father of Evolution

44

Darwin’s Theory of Natural Selection Individuals in a

population vary in their traits

45

Darwin’s Theory of Natural Selection Individuals in a

population vary in their traits

More offspring are produced than the environment can support

46

Darwin’s Theory of Natural Selection Individuals in a

population vary in their traits

More offspring are produced than the environment can support

Better-suited individuals reproduce more

47

Natural Selection Overview

Natural selection occurs as heritable variation responds to environmental factors that favor the reproductive success of some individuals over others

48

Current Example of Evolution – Multidrug-resistant Bacteria

EvolvedR to Penicillin obtained from a Mold Staphylococcus

49

Biological Diversity

50

Theory of Evolution explains the diversity seen in the natural world

Review of the Properties of Life

CELLULAR ORGANIZATION (or ORDER)

HOMEOSTASIS or REGULATION

GROWTH and DEVELOPMENT

METABOLISM and/or RESPONSE TO ENVIRONMENT

REPRODUCTION with DNA

HEREDITY (DNA) EVOLUTION

51

-Review of Cells

52

ANIMAL CELL

PLANT CELL

53

CELL SIZE COMPARISON

-Review of Cells

• Animal• Plant• Bacteria• Noncellular

viruses

54

SUMMARY

All living things share certain characteristics

The differences between living and non-living are not clear-cut

Levels of organization define biology and Different properties emerge at each level

55

SUMMARY

All living things share certain characteristics

The differences between living and non-living are not clear-cut

Living things are classified into domains and kingdoms

Levels of organization defines biology

The Scientific Method:How Scientists ThinkDeductive Reasoning Makes a decision by

applying a general principle

Inductive Reasoning Makes a general principle

by applying many different specific observations

56

Should I touch this piece of metal?

Two Approaches to Science

1. DISCOVERY SCIENCE No experiments Based on observations Inductive reasoning –

general principles derived from large number of specific observations

57

EXAMPLE: All living things are composed of cells

Two Approaches to Science

1. HYPOTHESIS-BASED SCIENCE Involves carefully planned experiments Based on observations Deductive reasoning – takes a general

statement and extrapolates specific results we would expect

58

How Scientists Think

Biology is a science, and all science must have merit, or it will not be accepted ....  How do scientists ensure that their facts and theories are accepted by others?  ...the scientific method!  

Pasteur's hypothesis testing of spontaneous generation.

59

The Scientific Method1.  make an observation.  Observe some aspect of

nature and ask a question about it.. 2.  develop a hypotheses about a possible answer

or solution to your question.3.  use hypotheses to make a prediction about ...

observe next, devise ... test your prediction with an experiment.

4.  if results do not confirm the hypothesis, discard or modify it.  Otherwise, repeat devise new tests to confirm your results.

5.  make a conclusion by analyzing ...  Report your findings.  

The Scientific Method hypotheses -an educated guess about an

observation.  ...not been tested. theory -in common English, an explanation

for an observation or an educated guess. scientific theory -an explanation that has

not been disproved after years of rigorous testing.  ... used ... to explain additional observations.  Evolution ...  main theory underlying all biology.

62

Example OBSERVATION: Millions

of fish are periodically killed in mysterious die-offs in the mid-Atlantic. Their bodies are covered in bleeding sores.

QUESTION: What is causing this to happen to these fish?

63

Hypothesis

What is an hypothesis? A testable explanation

that explains an observation

Addresses the question which came from the observation

Example Hypothesis: A microscopic protist, Pfiesteria, was killing the fish

What is your hypothesis about the fish die-offs?

64

Predictions

Based on the hypothesis Can be tested Example—two testable predictions

Pfiesteria would be found in larger numbers during the die-offs

Pfiesteria would be capable of killing healthy fish

65

Experiments Designed to test the predictions Results either support or refute hypothesis An experiment should only test ONE thing

(the variable) Everything else should be the same

(constant) You need something to compare to (control)

66

Experiments

Results from testing Pfiesteria was found where fish were dying Pfiesteria quickly killed the fish in the laboratory Pfiesteria infect and kill fish cells

67

Conclusion

Does the evidence presented support or refute the Pfiesteria hypothesis?

Note in science, we can disprove a hypothesis (refute it), but we can never prove it.

A disproven hypothesis can be revised to include new information.

68

The Scientific Process does not…

Make moral judgments Prove or disprove faith-based beliefs Determine personal aesthetic values Produce a FINAL answer because it is

always open to more testing. You can only support a hypothesis, not prove it.

Experiment

Does Brand X fertilizer really help my plants grow?

69

WATER

WATER +

FERTILIZER

Controlled Experiments Have:

TWO GROUPSExperimental groupControl group

INDEPENDENT VARIABLE – the one thing in the experiment different between the two groups. What you change in your experiment

CONSTANT Variables – the things that are the same between the groups

70

Controlled ExperimentControl Group Experimental Group

71

WATER

WATER +

FERTILIZER

INDEPENDENT VARIABLE?CONSTANTS?

Controlled Experiments

DEPENDENT VARIABLE – the thing (or things) in the experiment that you are measuring

The dependent variable DEPENDS on the independent variable

72

Control Group Experimental Group

73

WATER

WATER +

FERTILIZER

DEPENDENT VARIABLE?HINT: the dependent variable depends on the independent variable

74

Scientific Method - Discussion Problems Find a partner Discuss each scenario with your partner,

then share with the group Scientific Method problems