Ch 1:Biology and the Tree of Life

• 1. They use energy to do work
• 2. They are made of cells
• 3. They carry and process information
• 4. They reproduce
• 5. They evolve

• 1. The cell theory
• 2. The theory of evolution bynatural selection

A generalized phenomenon

• *Pattern component(based on observation)
• *Process component(based on experimentation)

• All organisms are made of cells (pattern)
• and all cells come from preexisting cells (process)

Robert Hook

Yes

No

• *Cells grew with an open flask
• *Cells didn't grow when there was a neck attached to the flask

Characteristics of populations change over time(pattern)

Because..individuals with some heritable characterssurvive better and reproduce better than otherindividuals. This is known as natural selection.(process)

Dark moths were more visible.they got eaten by birds. white moths were more visible on dark tree trunks.they got eaten by birds.

Tree trunks became darker due to pollution The result: Population of moths changed from white to dark. Evolution by natural selection.

Artificial selection is when humans select certain individuals for the benefit of humans

.Example: farmers select maize for high protein,strawberries for high sugar content,animals for better meat quality,flowers for colors, fragrance….

The Evolutionary Tree (phylogenetic tree)

• 1. Domain Bacteria
• 2. Domain Archae
• 3. Domain Eukarya

• -Eukaryotic cells are nucleus bound
• -Prokaryotic cells don't have a nucleus and are smaller than Eukaryotic cells.

• -Believed to be prokaryotic type cell
• -Contained some RNA as genetic material
• -And surrounded by a membrane