Download - Unit1 Lecture1
BIO 3
Introduction to Biology
Instructor: Francisca Herrera
Course Syllabus Course Requirements
Exams Unit Reviews Journals Forums
What is a living thing? What are the characteristics of life?
Living organisms are a carbon- and water-based cellular form with complex organization and heritable genetic information.
They undergo metabolism, possess a capacity to grow, respond to stimuli, reproduce, and, through natural selection, adapt to their environment in successive generations.
Properties of life
Living organisms are: a carbon- and water-based cellular form
Cell Theory Cells are basic structural and physiological units of all
living organisms Cells are both distinct entities and building block of
more complex organisms
Properties of life
Living organisms:undergo metabolism
Require Energy Cells use nutrients to supply energy
and build new structures Metabolism: the sum total of chemical
reactions that occur in an organism
Figure 1.2 Acquiring nutrient material and energy
Properties of life
Living organisms:respond to stimuli
Respond helps ensure the survival of an organism allows an organism to carry on daily activities
Properties of life
Living organisms:possess a capacity to grow…
reproduce
Reproduce and Develop: asexual reproduction (clonal):
produce exact replica of themselves
sexual reproduction (many strategies): exchange of genetic material between organisms
Figure 1.3 A Human Family
Properties of life
Living organisms have:heritable genetic information… through
natural selection, adapt to their environment
Heredity genome – all DNA molecules in a cell adaptation – an organism’s modification in structure,
function, or behavior suitable to the environment
Properties of life
Living organisms have:complex organization
Life Science biology is the scientific study of life
Life is complex! There are levels of life:
Figure 1.1 Levels of biological organization
SmallMolecules
LargeMolecules
Cells Tissues Organs OrganSystems
ComplexOrganisms
AnimalsFungiPlantsProtistsArchaeaBacteria0
1.0
2.0
3.0
4.0
0.5
1.5
2.5
3.5Bill
ions
of Y
ears
Ago
(BYA
)
BACTERIA
ARCHAEAEUKARYA
Life is complex! There is diversity of life:
Figure 1.4 Evolutionary tree
Figure 1.6 Domain Bacteria
Figure 1.5 Domain Archaea
• Prokaryotes: single-celled organisms
• Eukaryotes: multi-celled organisms
Figure 1.8 Kingdom Fungi
Figure 1.9 Kingdom Plantae
Figure 1.10 Kingdom Animalia
Figure 1.7 Kingdom Protista
Life is complex! There is taxonomic
order to life:
Life is complex! There is ecological
order to life:
Life is complex! Life is interconnected
and interdependent:
Heat
Heat
Heat
Che
mic
als
Che
mic
als
Decomposers
Consumers
Producers
Solarenergy
Figure 1.12 A grassland, a terrestrial ecosystem
The scientific process To understand such a
complex subject, scientists developed the scientific method: allows scientists to modify and
correct their beliefs as new observations and information becomes available
if well supported > theory!
Core Ideas of Biology A theory is a unifying explanation that has
been well supported time and time again. There are four major unifying themes in the
study of life.
Core Ideas of Biology
The Cell Theory: All organisms are composed of cells All cells come from other cells
Robert Hooke – named cells Anton van Leeuwenhoek –
“wee animalcules”
Core Ideas of Biology
The Gene Theory: All organisms have a genome An organism’s genes determine
what it will be like (secret code!)
James Watson and Francis Crick –
discovered DNA structure
Core Ideas of BiologyThe Theory of Heredity: The genes of any organism
are inherited as discrete units
Those genes are packaged up in chromosomes
Gregor Mendel – Mendelian segregation
Core Ideas of BiologyThe Theory of Evolution: Organisms that can respond to
the challenges of living will leave more offspring
Descent with modification!
Charles Darwin – living organisms are related to one another
Today’s Journal Entry Under the activities menu of the virtual
classroom, click on the Journals link Topic 1 – Introduction to Biology
There are no wrong answers in the journal entries.
Answer in complete sentences, in a clear and concise manner.