Lecture 2 and text (pg. 1,2,12-14)
1. What are some properties of life?
Growth and Development
Order - ordered structure
2. Evolution is the "overarching theme in biology".
Regulation of body processes
Fundamental Questions on the
Origin of Life
How could complex organic molecules form abiotically?
How could metabolism and replication evolve simultaneously?
How could cell membranes develop?
How could all of this happen so fast?
Life arose about 3 to 4 b
The Greatest Threat to Biodiversity
A. Habitat Loss
agriculture, cities, industrial processes, global
B. Introduced Species
global travel, species freed from natural constraints
Zebra mussels, purple loosestrife
Selection requires genetic variation
How does genetic variation arise?
o point mutations
like mouse example where chromosomes change
we have 46 chromosomes
- sexual reproduction
o mixes genes into new combina
Allopratric Speciation - physical separation
Isolating mechanism is geographic
Sympatric Speciation - even though gene flow is possible, some factor prevents
Gene flow is a barrier to sympatric
Descent (Unity) with Modification (Diversity)
Natural Selection explains diversity, therefore diversity would be maintained between
However, it would reduce variation within a
Evolution - the change in the genetic composition of a
Modern Views of Biodiversity
Current Hierarchical System
Both genus and epithet and in the species name
eg) Canis lupus - wolf
Zea mays - corn
Hierarchical Systems can be shown as
Everything else in the plant not vascular tissue or dermal tissue
Basic cell type
Shoot - includes stem and leaves
Leaf: blade and petiole
Root - underground portion of the plant
Shoot Apical Meristem
Evolution of Multicellularity
Benefits of Multicellularity
Recall our plucky little eukaryotic cell.
It's MOC can run flagellae or cilia giving the cell mobility, OR they can produce the spindles used in
mitosis. But NOT both at the same time.
Tissue - integrated group of cells with a common function or structure
Made up of one cell type:
Made up of more than one cell type
Three Tissue Regions