Upload
camiila-garcia
View
220
Download
5
Embed Size (px)
Citation preview
Evolution and Life on Earth
Lecture 2
Friday, March 15, 13
Topics Covered in this Module • Life on Earth• Evolution: The Core Theme in Biology
Major Objectives of this Module • Identify evolution as the core theme and unifying
concept in biology.• Distinguish between the biological and the
common meanings of the word evolution.• Explain how evolution has led to both the unity
and the diversity of life forms.
Friday, March 15, 13
Life on Earth
A cuttlefish senses its surroundings through its w-shaped pupil.
The eye sends information to the brain, which quickly relays messages to particular pigment cells in the skin. The muscles pull on the pigment cells so they expand, and the cuttlefish instantly resembles what its eye sees. Evolution is behind the formation of these traits.
Friday, March 15, 13
Figure 2: Cells, the basic units of life.
All cells have cell membranes, ribosomes, and DNA. The DNA is packaged differently in eukaryotic and prokaryotic cells, but it has the same basic structure and function.
Friday, March 15, 13
• Sources of Genetic Variation
• Mutations
• Gene Recombination
DNA is a great unifier for all of life
• Biological Evolution
• Process that results in heritable changes
Friday, March 15, 13
Figure 5: Biological classification.
The classification system in use today relies on the hierarchical system developed by Linneaus, with the addition of several categories, including the domain - the most inclusive category. This schematic shows the classification of the polar bear (Ursus maritimus).
Friday, March 15, 13
Natural Selection
Natural Selection is the process whereby organisms better adapted to their environment tend to survive and produce offspring.
Friday, March 15, 13
Evolution explains the unity of life.
Figure 9: Homologies.
The forelimbs of a variety of mammals use the same bones, slightly modified, for different purposes. The genes that code for the bones are also very similar. These similarities that arise from sharing a common ancestor are called homologies. The forelimbs in mammals are considered homologous structures. Homology is the phenomonon of homologies among different organisms.
It all comes down to DNAFriday, March 15, 13
Friday, March 15, 13
Friday, March 15, 13
Friday, March 15, 13
Three-Domain tree of Life
Comparing sequences of a conserved ribosomal gene in archaea with the same gene in other prokaryotes and eukaryotes, scientists found that archaea were so different from eukaryotes and even from other prokaryotes that they deserved an entirely new classification category.
Friday, March 15, 13
Evolutionary thinking applies to all levels of biological
organization.
Friday, March 15, 13
Biological Information and Interactions
Friday, March 15, 13
Topics Covered in this Module • Organisms Are Centers of Information
Transfer• Responding to Information
Major Objectives of this Module • Describe how living things inherit genetic
information.• Explain how cells receive, process, and
respond to signals from their environment.
Friday, March 15, 13
What about animals/humans?
Friday, March 15, 13
Central Dogma of Molecular Biology
Friday, March 15, 13
• Information is stored
• Genes are the functional units of information
• Information is interpreted and transmitted
• Information goes from “virtual” to “real”
Friday, March 15, 13
Double strand DNA
Friday, March 15, 13
Storing and interpreting DNA instructions.
One DNA molecule contains many genes. The DNA consists of two strands that are joined by base pairing between complementary nitrogenous bases. Each strand of DNA can therefore act as a template, or pattern, either for completing the other DNA strand or for producing mRNA, a mobile copy of the information in the base sequence. The mRNA then serves as the template for assembling a specific sequence of amino acids.
Friday, March 15, 13
General Transfer
Friday, March 15, 13
Special Transfer
Friday, March 15, 13
Responding to Information
Sense, transmit, process and answer back at all levels of biological organization:
Chemical ReactionCell Signaling
Friday, March 15, 13
Energy and Matter
Lecture 3
Friday, March 15, 13
Friday, March 15, 13
Topics Covered in this Module • Matter and Energy in the Earth System
Major Objectives of this Module • Define energy and matter.• Explain how energy and matter interact on multiple
levels of biological organization from cells to organisms to ecosystems to the Earth system.
• Explain how organisms use energy and matter to form living structures and perform life processes.
Friday, March 15, 13
• What is Matter?
• What is Energy?
Friday, March 15, 13
Friday, March 15, 13
Thermodynamics
First Law: Energy is not created or destroyed. It can be just transformed
Second Law: Every transformation of Energy has a lost as Heat. This Heat increases the entropy of
the universeFriday, March 15, 13
Different Kind of Energy
Friday, March 15, 13
Friday, March 15, 13
Friday, March 15, 13
Friday, March 15, 13
Friday, March 15, 13
Friday, March 15, 13
Figure 2-56 Molecular Biology of the Cell (© Garland Science 2008)
COUPLED REACTIONS
Friday, March 15, 13
Exergonic and Endergonic Reactions
Friday, March 15, 13
Friday, March 15, 13
• Coupled Reactions• Activated Carriers
Friday, March 15, 13
Figure 2-69 Molecular Biology of the Cell (© Garland Science 2008)
Friday, March 15, 13
ATP is the most used Act. Carrier
Friday, March 15, 13
ANOTHER ENERGETIC CARRIER
Friday, March 15, 13
ANOTHER ENERGETIC CARRIER
Friday, March 15, 13