2. ALL FORMS OF LIFE SHARE COMMON PROPERTIES
• Biology is the scientific study of life
• There are seven properties of life
3. Growth & Development
4. Energy Processing
5. Response to the environment
7. Evolutionary Adaptation
4. BIOLOGICAL ORGANIZATION
The Hierarchy of Life
Emergent Properties are new properties that arise in each step upward in the hierarchy
- Atom: Smallest unit of an element composed of electrons, protons and neutrons.
- Molecule: Union of two or more atoms of the same or different elements.
- Organelle: A membrane-bound structure that performs a specific function in a cell.
- Cells: The fundamental unit of life.
- Tissues: A group of similar cells that perform a specific function.
- Organ: A structure that is composed of tissues and that provides a specific function
for the organism.
- Organ system: Several organs that cooperate in a specific function.
- Organisms: An individual living thing
5. BIOLOGICAL ORGANIZATION
- Population : A group of organisms from the same species living in a
-Community: The entire array of organisms living in a particular area
- Ecosystem: All the organisms living in a particular area including the
physical components with which the organisms interact
[Community + Physical environment]
- Biosphere: All of the environments on Earth that support life.
7. CELLS ARE THE STRUCTURAL AND FUNCTIONAL UNITS
• Cells are the level at which the properties of life emerge
• A cell can regulate its internal environment, take in and use energy, respond to its
environment, develop and maintain its complex organization and give rise to new cells.
• All cells are enclosed by a membrane that regulates the passage of materials between the
cell and its surroundings.
• All cells use DNA as their genetic information.
8. CELLS ARE THE STRUCTURAL AND FUNCTIONAL UNITS
• There are two basic types of cells
1. Prokaryotic cells
• Were the first to evolve,
• Are simpler, and are usually smaller than eukaryotic cells
2. Eukaryotic cells
• Contain membrane-enclosed organelles including a nucleus containing DNA and are found
in plants, animals and fungi.
• Cells illustrate another theme in biology: the correlation of structure and function.
• Structure is related to function at all levels of biological organization.
10. THE UNITY OF LIFE IS BASED ON DNA AND A COMMON
• All cells have DNA, the chemical substance of genes.
• Genes are the unit of inheritance that transmits information from parents to offspring.
• They are grouped into very long DNA molecules called chromosomes, and control the activities of a
• A species’ genes are coded in the sequences of the four building blocks making up DNA’s double
- All forms of life use essentially the same code to translate the information stored in DNA
- The diversity of life arises from differences in DNA sequences.
11. THE DIVERSITY OF LIFE CAN BE ARRANGED INTO THREE
The diversity of life can be arranged into three domains.
1. Bacteria are the most diverse and widespread of prokaryotes.
2. Archaea are prokaryotes that often live in Earth’s extreme environments.
3. Eukarya have eukaryotic cells and include single-celled protists and multicellular fungi, animals
13. EVOLUTION EXPLAINS THE UNITY AND DIVERSITY OF
• The history of life, as documented by fossils, is a saga of a changing Earth billions of years old and
inhabited by an evolving cast of life forms.
• Evolution accounts for life’s dual nature of kinship and diversity.
16. EVOLUTION EXPLAINS THE UNITY AND DIVERSITY OF
In 1859, Charles Darwin published the book On the Origin of Species by Means of Natural
Selection, which articulated two main points.
1. A large amount of evidence supports evolution; species living today are
descendants of ancestral species in what Darwin called “descent with
2. Natural selection is a mechanism for evolution.
a. Individuals DO NOT evolve: populations evolve.
b. Natural selection can amplify or diminish only heritable traits. Acquired
characteristics CANNOT be passed on to offspring.
c. Evolution IS NOT goal directed and DOES NOT lead to perfection. Favorable
traits vary as the environment changes.
• Many of a cell’s reactions take place in organelles and use enzymes in membranes of
• Hydrolysis of ATP releases energy by transferring its third phosphate from ATP to
some other molecule in a process called phosphorylation
• How do organisms acquire energy?
26. CARDIOVASCULAR DISEASES [JUST A FEW EXAMPLES]
• Myocardial Infarction
• Coronary Artery Disease
• Arrhythmias (Abnormal heart rhythms)
• Congenital heart disease (tetralogy of Fallot)
27. VENTRICULAR SEPTAL DEFECT
• A ventricular septal defect (VSD) is a birth defect of the heart in which there is a hole in the wall (septum) that
separates the two lower chambers (ventricles) of the heart. This wall also is called the ventricular septum.
• In babies with a ventricular septal defect, blood often flows from the left ventricle through the ventricular septal
defect to the right ventricle and into the lungs. This extra blood being pumped into the lungs forces the heart
and lungs to work harder. Over time, if not repaired, this defect can increase the risk for other complications,
including heart failure, high blood pressure in the lungs (called pulmonary hypertension), irregular heart rhythms
(called arrhythmia), or stroke.
Division of Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention
28. Division of Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention
Normal Heart Ventricular Septal Defect
In life’s hierarchy of organization, new properties emerge at each level
Both contain DNA, RNA, Ribosomes, Protein, Cell Membrane….
Phylogeny of the animal kingdom
The great thing about looking backwards like we've done with reptilian evolution is that it gives us a really good handle on how we can now look forward and try to understand how a protein like Tbx5 is involved in forming the heart and how in the case of congenital heart disease its function is impaired.