The Science of Biology

Chapter1

Chapter 1: The Science of Biology

• What makes something “alive”?– 1. Cellular organization– 2. Order– 3. Sensitivity– 4. Growth,development, and reproduction– 5. Energy Utilization– 6. Evolutionary adaptation– 7. Homeostasis

Hierarchical OrganizationAtoms Molecules Macromolecule

Tissue Cell OrganelleOrgan Organ system Organism

Community Species PopulationEcosystem Biosphere

Two Types of Reasoning Scientists Use

• Deductive Reasoning

• Inductive Reasoning

Scientific Method

Darwin Was a Pretty Cool Guy… I Mean Just Check Out that Beard!

The Galapagos Islands- Disney World for Scientists

• Darwin found a lot of evidence to support his theory on the Galapagos Islands- specifically in the finches.

Only the Strong Survive?

• Darwin and Malthus

Who’s that Wallace Guy Anyway?

• A man named Alfred Wallace concurred with Darwin’s theory of evolution via natural selection.

• This lit a fire under Darwin and led him publish his findings

Modern Evidence Supporting Darwin’s Theory

• 1. The fossil record• 2. The age of Earth- 4.5 billion years as opposed to a

few thousand as thought in Darwin’s Time• 3. Genetics supports Darwin’s Theory• 4. Comparative Anatomy- Homologous and Analogous

structures• 5. Molecular evidence- comparing genomes ( the

sequences of genes) in species• 6.Molecular Clocks- Similarities in DNA of related

individuals• 7. Phylogenetic Trees- the sequences of genes are used

to construct these

Constructing a Phylogenetic Tree

• Most Related= Smallest number of Amino Acid differences

• Least Related= Largest number of Amino Acid Differences

# of Differences

Animal

50 Chicken

10 Monkey

70 Frog

30 Dog

0 Human

Important People In the Cell Thory

• Robert Hooke• Anton van Leeuwenhoek• Matthias Schleiden and Theordor

Schwann

Cell Theory

• All organisms are composed of one or more Cells

• Cells are the smallest living things and the basic units of all live

• All cells come from other cells ***Is this always true***

The molecular Basis of Inheritence

• DNA- Encodes all of the information in a cell

• Gene- larges sequences of nucleotides making a discrete unit of information

• Genome- the entire set of DNA instructions that specifies a cell

Structure and Function

• Underlying theme of biology• Function is highly dependant on structure

Why is it important to relate the structure of something with its function?

Evolutionary Change

• All organisms are classified into three main domains and then further classified from there

Evolutionary Conservation

• All living things descended from a simple cellular creature about 2.5 billion years ago.

• Some characteristics of the earliest organism have been preserved in all living things

• Examples?