Welcome to Biology 101 (RCGC)

Dr. Robert Anderson Rowan College of Gloucester County

What Rules Do You Follow?

Physics – gravity, electricity, time, forces, etc.

Chemistry (Physiology) – diffusion, chemical reactions, protein synthesis

Biology – cells, organs, photosynthesis, organisms, healing, ecology, evolution, etc.

What is BIOLOGY?

• Biology is the scientific study of life

• Biologists are moving closer to understanding:

– How a single cell develops into an organism

– How plants convert sunlight to chemical energy

– How the human mind works

– How living things interact in communities

– How life’s diversity evolved from the first microbes

Outline

• 1) Biological Organization• 2) DNA and Cells

• The human genome project• 3) Systems Biology and putting together information

• Feedback systems in living cells• 4) Taxonomy – naming all of the organisms• 5) Diversity of species

• The theory of evolution• The theory of natural selection

• 6) The scientific method• 7) Examples of field studies employing the scientific method• 8) Theories in science

Biologists study the properties of life!

• Biologists explore life from the microscopic (Microbiology) to the global scale (Ecology and Evolution)

• The study of life extends from molecules and cells to the entire living planet (biosphere)

• Biological organization is based on a hierarchy of structural levels from simple to complex

• Each level of biological organization has its own set of properties

Life’s Basic Characteristic is Order

A Hierarchy of Biological Organization

1. Biosphere: all environments on Earth – basically encompasses the entire planet.

2. Ecosystem: all living and nonliving things in a particular area.

3. Community: all living organisms present in an ecosystem. Each identical life form is known as a species.

4. Population: an isolated group of individuals of the same species living within a particular area.

5. Organism: an individual living thing.

LargestLevel

SmallerLevels

A Hierarchy of Biological Organization (continued)

6. Organ and organ systems: specialized body parts made up of tissues comprise an organ. Several organs come together to form an organ system.

7. Tissue: a group of similar cells.8. Cell: life’s fundamental unit of structure and

function. Some organisms consist of single cells (unicellular organisms), while others contain billions of cells (multicellular organisms).

9. Organelle: a functional or structural component of a cell.

10. Molecule: a chemical structure consisting of two or more atoms.

LargerLevels

SmallestLevels

Ecosystems

The biosphere

Organisms

Populations

Communities

Cells

Organelles

Molecules

Tissues

Organs and organ systems

Cell1 µm

Atoms

10 µm

50 µm

An Example of the Hierarchy of Biological Organization

Important Underlying Themes: The Fundamentals of Biology

1. New properties emerge at each level of biological organization

2. Organisms react with each other and the physical environment

3. Life requires energy transfer and transformation4. Structure dictates function (like number 1)5. The cell is the basic unit of life6. DNA allows species to pass information down through the

generations 7. Feedback mechanisms regulate biological systems8. Evolution accounts for biodiversity

Theme 1: New properties emerge at each level of biological

organization

• Structure dictates function!

• Evolution has allowed living organisms to accomplish many complex actions through organization

• This organization allows the whole organism to function in its environment, but it also allows the body to function internally giving it emergent properties

• Should the structure of a living thing be disrupted, life processes will be affected (usually in a bad way!)

Making Sense of Complex Organization

• Reductionism – a system can be studied at any level or organization by breaking it down into its component parts

• However, individual parts do not act the same as the complete system, and may not provide a good explanation for how living things work

• Systems biology is an approach that tries to model what happens in a complete system by adding, subtracting or changing the variables know to affect the system

• This is the fundamental philosophy of working in SCIENCE!!!

Systems Biology

• Systems biology seeks to create models of the dynamic behavior of whole biological systems

• An example is a systems map of interactions between proteins in a fruit fly cell• Such models may predict how a change in one part of a system will affect the rest of

the system

CELL

Nucleus

Cytoplasm

Outer membraneand cell surface

Example - Sequencing the Human Genome

•In 1990 our government launched the Human Genome Project (HGP)•it was expected to take 15 years and cost over 3 billion dollars•goals of the project:

1. map all of the human genes2. construct a detailed physical map of the entire human genome3. determine the nucleotide sequences of all 24 human chromosomes

Results

• By 2004 (14 years later) we sequenced 2.85 BILLION base pairs which translated to roughly 22,287 genes

•Does this allow us to understand how the whole human body works?

Other Examples?

• What happens to an ecosystem if a species goes extinct?

• Is a newly approved drug safe for people that have immune problems?

•

•

•

Theme 2: Organisms react with each other and the physical environment

• Each organism interacts with its environment• Both organisms and environment affect each other

• Examples• Cycling of nutrients occurs when plants make sugar and oxygen from

sunlight, carbon dioxide and water• Animals then eat the plants, breaking down sugar and breathing in the

plants oxygen to make CO2 and water, thus feeding the plant and completing the cycle

• Other examples? What is happening on the larger scale?

Climate Change – Fact or Fiction?

Theme 3: Life requires energy transfer and transformation

• Activities of life require the living organism to do some type of work

• Work depends on sources of energy

• Energy exchange between an organism and environment often involves energy transformations i.e. from sunlight to chemical energy

• In transformations, some energy is lost as heat

• Energy flows through an ecosystem, usually entering as light and exiting as heat

Sunlight

Ecosystem

Heat

Heat

Cyclingof

chemicalnutrients

Producers(e.g. plants)

Chemical energy

Consumers(such as animals)

Theme 4: Structure Dictates Function

• What can you say about the diet of these animals?

• Other Examples?

Theme 4: Structure Dictates Function

Theme 5: The cell is the basic unit of life

• The cell is the smallest level of biological organization that can perform all activities of life

• The ability of cells to divide is the basis of all reproduction, growth, and repair of multicellular organisms

25 µm

Theme 6: DNA allows species to pass information down through the generations

• Cells contain DNA, (deoxyribonucleic acid), the heritable information that directs the cell’s activities

• DNA is what makes up our genes• Genes are the units of inheritance that transmit genetic

information from parents to offspring

Sperm cell

NucleicontainingDNA

Egg cell

Fertilized eggwith DNA fromboth parents

Embryo’s cells With copies of inherited DNA

Offspring with traits inherited from both parents

In 1953, Watson and Crick suggested a 3D structure for DNA

• Each DNA molecule is made up of two long chains arranged in a double helix• Each link of a chain is one of four kinds of chemical building blocks called

nucleotides

What is DNA?

More (much more) on this later…..

DNA double helix Single strand of DNA

Nucleotide

Cell

Nucleus DNA

Structure of DNA

How do Living Things Work?

• Why do children look like their parents?

• Why can’t different species breed and make offspring?

• What causes predictable change in an organism over time?

• What determines behavior?

• So many questions! – best to start with a simple organism…..

Frederick Griffith (1928) observed that virulent (deadly) Streptococcus bacteria, when heat-inactivated and mixed with a nonvirulent strain, could “transform” the nonvirulent strain and make it virulent.

Griffith’s Experiment

What Happened?

Group Hypothesis

1.

2.

3.

4.

Frederick Griffith (1928) observed that virulent (deadly) Streptococcus bacteria, when heat-inactivated and mixed with a nonvirulent strain, could “transform” the nonvirulent strain and make it virulent.

Griffith’s Experiment

Implications?

This showed that DNA was the inheritable material

Theme 7: Feedback mechanisms regulate biological systems

• Many biological processes are self-regulating: the product regulates the process itself. The end product of a specific reaction works to feed-back on the process.

• In negative feedback, the accumulation of a product slows down the process itself

• In positive feedback (less common), the product speeds up its own production

• Regulatory systems ensure a dynamic balance in living systems• Chemical processes are catalyzed (accelerated) by enzymes

• Examples?

Negative Feedback

• Increasing amounts of product “D” shuts off enzyme 1.

• This turns off the production of product

• The product limits its own production

Enzyme 1

A A

BB

C C

D

D

D

D

DD

DD

D

DD

Enzyme 2

Enzyme 3

Enzyme 1

W

Enzyme 4

W

XX

Y Y

Z

Z

Z

ZZ

ZZ

ZZ

Z

Enzyme 5

Enzyme 6

Enzyme 4

Enzyme 6

Enzyme 5

ZZ ZZ

ZZ

Z

Z

Z

Positive Feedback

• Increasing amounts of product “D” activates enzyme 1.

• This increases the production of product

• The product increases its own production

Evolution Drives Change in Living Things

• The sum of living things on the planet is called the Earth’s biodiversity

• The theory of evolution operates on the hypothesis that all life originated from a common ancestor (LUCA – the Last Universal Common Ancestor)

• All of the different living things that have appeared since then are the results of 3 forces:

• Mutation – genetic change• Time – time is needed for minute changes to accumulate and cause physical

change – thereby leading to diversity• Selection – an organisms environment leads to “survival of the fittest”,

allowing the best suited individuals to reproduce and forward their genes to the next generation

• Biologists have named about 1.8 million species• Estimates of total species living in the biosphere range from 10 million to over

200 million• How do we organize species within the framework of biological organization?

Within the biosphere, how do we organize the naming of the individual species?

• Taxonomy is the branch of biology that names and classifies species into a hierarchical order

• Kingdoms and domains are the broadest units of classification• Levels of Taxonomic organization (ordered largest to smallest):

• Domain, Kingdom, Phylum or Division , Class , Order, Family, Genus, Species

Biologists Explore Life in MANY Species

Ursidae

Ursus

Carnivora

Mammalia

Chordata

Animalia

Eukarya

Species Genus Family Order Class Phylum Kingdom DomainUrsusamericanus(Americanblack bear)

Humans full name is: Eukarya

anamalia chordata mammalia

primates hominoidea homo sapiens

Taxonomic organization of a Black bear

The Three Domains of Life

• At the highest level, life is classified into three domains:

• Archaea – prokaryotes, odd bacteria that live in extreme environments, high salt, heat, etc

• Eubacteria – prokaryotes, true bacteria

• Eukarya – eukaryotes that have a nucleus, & organelles, Eukaryotes include protists and the kingdoms Plantae, Fungi, and Animalia

Archaea Eubacteria Eukarya

Nomenclature we will use, and is most commonly used in science

• Binomial (scientific) nomenclature

• Genus – Homo, first letter is uppercase

• species - sapiens, lowercase

• Both italicized or underlined

– Homo sapiens (H. sapiens)

– Tyrannosaurus rex (T. rex)

– Others?

• The theory of evolution has been proposed by biologists to explain the diversity that arises between species

• The history of life is a saga of a changing Earth billions of years old• The evolutionary view of life came into sharp focus in 1859, when Charles

Darwin published On the Origin of Species by Natural Selection• “Darwinism” became almost synonymous with the concept of evolution

Where Does Diversity Between Species Come From?

• Descent with modification (the view that contemporary species arose from a succession of ancestors)

• Natural selection (a proposed mechanism for descent with modification) • Darwin inferred natural selection by connecting two observations:

• Observation: Individual variation in heritable traits – inference: unequal reproductive success

• Observation: Overpopulation and competition - inference: Evolutionary adaptation

• Natural selection can “edit” a population’s heritable variations

The Origin of Species articulated two main points:

Factors Driving Change

Populationof organisms

Hereditaryvariations

Overproductionand competition

Differences inreproductive successof individuals

Evolution of adaptationsin the population

Environmentalfactors

The Theory of Natural Selection

Each island in the Galapagos had different food types

This “selected” for finches that had bills that were suited to handle each food type

This is called Adaptive Radiation

• Inquiry is a search for information and explanation, often focusing on specific questions

• The process of science blends two main processes of scientific inquiry:• Discovery science: describing nature – slowly finding things that describe

data that you obtain when doing observations – this leads to a hypothesis• Hypotheses are formed to test variable that may explain what has been observed

• Hypothesis-based science: explaining nature – slowly finding out and trying to explain what you see in nature, discrete testing

Methods Used to Study Life

Discovery Science

• Discovery science describes nature through careful observation and data analysis

• Examples of discovery science:• understanding cell structure• expanding databases of genomes

• Two types of data, or recorded observations generated during the course of an experiment:

• Quantitative data: numerical measurements• Qualitative data: recorded descriptions

• Inductive reasoning involves generating ideas to explain many specific observations or data

https://www.youtube.com/watch?v=VXW5mLE5Y2g

Deductive Reasoning vs. Inductive Reasoning

Hypothesis-Based Science

• In science, inquiry usually involves proposing and testing hypotheses• Hypotheses are hypothetical explanations that you try to experimentally test

to show that the explanation describes nature• In science, a hypothesis is a tentative answer to a well-framed question• A role of a hypothesis is that it is an explanation on trial, making a prediction

that can be tested

Hypothesis #1:Dead batteries

Hypothesis #2:Burnt-out bulb

Observations

Question

Step 1: Formulating hypotheses

(Flashlight doesn’t work)

Hypothesis #1:Dead batteries

Hypothesis #2:Burnt-out bulb

Test prediction

Test falsifies hypothesis

Prediction:Replacing batterieswill fix problem

Prediction:Replacing bulbwill fix problem

Test prediction

Test does not falsify hypothesis

Step 2: Testing your hypotheses

What needs to be answered?

What is already known?

Pose an explanation in the form of a question.

How to address the questions/get answers?

Collect/analyze data from the experiment.

Explain the in terms of your hypothesis

Example - Explaining Mimicry

• In mimicry, a harmless species resembles a harmful species• An example of mimicry is a stinging honeybee and a nonstinging mimic, a

flower fly

Flower fly (nonstinging)

Honeybee (stinging)

• This case study examines king snakes’ mimicry of poisonous coral snakes• The hypothesis states that mimics benefit when predators mistake them for

harmful species• The mimicry hypothesis predicts that predators in non–coral snake areas will

attack king snakes more frequently than will predators that live where coral snakes are present

Field study: Researching mimicry in the wild

Scarlet king snake

Eastern coralsnake

Scarlet king snake

KeyRange of scarlet king snake

NorthCarolina

Range of easterncoral snake

SouthCarolina

Field Experiments with Artificial Snakes

• To test this mimicry hypothesis, researchers made hundreds of artificial snakes:

• An experimental group resembling king snakes • A control group resembling plain brown snakes

• Equal numbers of both types were placed at field sites, including areas without coral snakes

• After four weeks, the scientists retrieved the artificial snakes and counted bite or claw marks

• The data fit the predictions of the mimicry hypothesis

(a) Artificial king snake

(b) Artificial brown snake that has been attacked

In areas where coral snakes were present, most attacks were on brown artificial snakes.

In areas where coral snakeswere absent, most attacks

were on artificial king snakes.

% of attacks onartificial king snakes% of attacks onbrown artificial snakesField site withartificial snakes

83%

NorthCarolina

SouthCarolina

17%

16%

84%

Key

Making the Case – Descriptive Data

Designing Controlled Experiments

• Scientists do not control the experimental environment by keeping all variables constant

• Researchers usually “control” unwanted variables by using control groups to cancel their effects

• The limitations of science are set by its naturalism• Science seeks natural causes for natural phenomena• Science cannot support or falsify supernatural explanations, which are

outside the bounds of science

Theories in Science

• A scientific theory is much broader than a hypothesis• A scientific theory is:

• broad in scope• general enough to generate new hypotheses• supported by a large body of evidence

• Models are often used to explain and simplify observations. Models are representations of ideas, structures, or processes

• Models may range from lifelike representations to symbolic schematics

Examples?

What Can You Say About Your Classmates (in general)?

• Is there something you can say in general about your class? Or groups of people in your class?

• How do you get people to believe you?

• Let’s Experiment! (see handout)

The Culture of Science and Technology

• Science is an intensely social activity• Individuals in science work together towards a common goal, and MUST be

able to communicate very effectively• Both cooperation and competition characterize scientific culture• The goal of science is to understand natural phenomena