Biology 112 - Lecture 1

What Does It Mean to Say That Something Is ALIVE? (5 aspects)

1. cells

2. replication

3. information

4. energy

5. evolution

cells

all living organisms are made up of membrane-bound cells.

replication

all LIVING organisms are capable of reproducing.

Information

all living organisms process HEREDITARY information , as well as info. from the environment.

Energy

all living organisms acquire and use energy

evolution

populations of organisms are continually evolving

Cell Theory

• All organisms are made of cells.

• All cells come from preexisting cells

Louis Pasteur’s hypothesis:

– Cells arise from cells
– Cells do not arise by spontaneous generation

Concluded that all-cells-from-cells hypothesis was
correct

common ancestry

All cells and all organisms are related

• Charles darwin

• Wallace 

Both proposed that all species are related by common ancestry

Descent with modification

- children of somebody will be different from each other, they will vary. Is a process*

or

Characteristics of species can be modified from generation
to generation

Evolution

- change in characteristics of population overtime. 

Natural selection

- how evolution occurs.

INDIVIDUALS VARY!!*

Population

A group of individuals of the same species
living in the same area at the same time

Requirements for natural selection:

1. Individuals vary in heritable characteristics

2. In a particular environment, certain heritable traits
help individuals survive better or reproduce more
than do other versions.

Acts on individuals →

Natural selection

Occurs in populations →

Evolutionary change

Within the population…

individuals might have better adaptations needed for the situation.

Fitness= more kids

Beneficial Characteristics= selection favors it more so more individuals will produce those genes

All organisms are related

• because all cells derive from other cells
  •A Phylogenetic tree attempts to clarify this
  relationship

Bacteria

..is a living organism

3 groups of all living things

• Eukaryotes- humans, animals, amoeba 

• Prokaryote - bacteria

• Archea - organism

A virus is

NOT (Not alive)

3 groups of all living things

• Eukaryotes- humans, animals, amoeba 

• Prokaryote - bacteria

• Archea - 

• Eukaryotic and prokaryotic cells differ in
  structure
  

Eukaryotes

• have a nucleus

• include: humans, animals, amoeba 

Prokaryotes

• lack a nucleus

• bacteria and archaea