Transcript Unit 2 Module 1 Characteristics of Living Things

Finding Order in Diversity
Biology is divided into different fields
because of the wide diversity of
organisms.
There are about 1.5 million species that
have been identified and named so far;
scientists estimate there are between 2
and 100 million additional species that
have not yet been discovered.
Unit 2 Notes
1
Finding Order in Diversity
Because there are so many organisms,
biologists use a classification system to
name organisms and group them in a
logical manner.
Why isn’t it good enough to use common
names of organisms?
Unit 2 Notes
2
Finding Order in Diversity


Taxonomy – discipline of classifying
organisms and giving each a universally
accepted name
We currently use a system of binomial
nomenclature - introduced by Carolus
Linnaeus, an 18th-century Swedish
botanist.
Unit 2 Notes
3
Binomial Nomenclature

Each species is assigned a two-part
scientific name, always written in italics,
first name capitalized, second in lower
case. Linnaeus’s system is hierarchical
(made up of levels).
Unit 2 Notes
4
Linnaeus’s System
1.
2.
3.
4.
5.
6.
7.
Kingdom – Linnaeus’s largest & most inclusive
category
Phylum – several different classes that share
important characteristics (like a backbone)
Class – group of similar orders
Order – group of similar families
Family – genera that share many
characteristics
Genus – group of closely related species
Species – group of similar organisms that can
breed and produce offspring
Unit 2 Notes
5
Linnaeus’s System
Grizzly bear Black bear
Giant
panda
Red fox
Coral Sea star
Abert
squirrel snake
KINGDOM Animalia
PHYLUM Chordata
CLASS Mammalia
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos
Unit 2 Notes
6
Memory Device

It helps to have a memory device to
remember the order of Linnaeus’s
categories. Here’s one that’s widely
used to remember the groups from
largest to smallest:
King Philip Came Over For Good Soup
[Kingdom-Phylum-Class-Order-Family-Genus-Species]
Unit 2 Notes
7
Memory Device

Can you think of another
sentence that would work
better for you? Use the space
on your notes page to come up
with your own memory device.
Unit 2 Notes
8
Panthera leo?
There’s a ws to go with this make sure you have it.
Unit 2 Notes
9
Kingdoms and Domains




Linnaeus divided organisms into 2 kingdoms –
Animalia and Plantae.
Scientists now consider these to be
inadequate to represent the full diversity of
life.
Now We have six Kingdoms
First, scientists agreed that microorganisms
needed their own kingdom (Protista).
Unit 2 Notes
10
Kingdoms and Domains


Then, mushrooms, yeasts, and molds
were grouped into Kingdom Fungi, while
bacteria were placed into Kingdom
Monera.
Recently, scientists have recognized
that bacteria were composed of two
distinct groups, now called Kingdoms
Eubacteria and Archaebacteria.
Unit 2 Notes
11
This makes the total number of
kingdoms 6.






1.Animalia
2. Plantae
3. Fungi
4. Protista
5. Eubacteria
6. Archaebacteria
Kingdoms and Domains

By analyzing molecules of various
organisms, a new taxonomic category
has arisen – the domain. This is a more
inclusive category than kingdom.
Unit 2 Notes
13
Three Domains
There are 3 domains:
1.
2.
3.
Eukarya – protists, fungi, plants, and
animals
Bacteria – corresponds to kingdom
Eubacteria
Archaea – corresponds to kingdom
Archaebacteria
Unit 2 Notes
14
Concept Map
Living
Things
are characterized by
Nucleus:
Eukaryotic
cells
and differing
Important
characteristics
which place them in
Cell wall
structures
such as a
nucleus
Domain
Eukarya
No nucleus:
Prokaryotic cells
which is subdivided into
which place them in
Domain
Bacteria
Domain
Archaea
which coincides with
which coincides with
Kingdom
Eubacteria
Kingdom
Archaebacteria
Kingdom
Plantae
Kingdom
Fungi
Unit 2 Notes
Kingdom
Protista
Kingdom
Animalia
15
Modern Evolutionary
Classification
Phylogeny – classification based on
evolutionary relationships among
organisms.
This study is based on Darwin’s ideas
about descent with modification.
Biologists now group organisms into
categories representing lines of
evolutionary descent rather than
physical similarities.
Unit 2 Notes
16
Modern Evolutionary
Classification

Cladistic analysis – looks at derived
characters (evolutionary innovations) new characteristics that develop within
a group over time


This involves analyzing genetic similarities
Cladogram – diagram based on derived
characters to show evolutionary
relationships among a group of
organisms
Unit 2 Notes
17
Cladogram
Appendages
Crab
Conical Shells
Barnacle
Limpet
Crab
Barnacle
Limpet
Molted
exoskeleton
Segmentation
CLASSIFICATION
BASED ON VISIBLE
SIMILARITIES
Unit 2 Notes
18
Cladogram
Appendages
Crab
Conical Shells
Barnacle
Limpet
Crustaceans
Crab
Gastropod
Barnacle
Limpet
Molted
exoskeleton
Segmentation
Tiny free-swimming larva
CLASSIFICATION
BASED ON VISIBLE
SIMILARITIES
CLADOGRAM
Unit 2 Notes
19
Genetic Similarity


Genetic similarity – can be used to
determine evolutionary relationships
using DNA sequence analysis.
Molecular clock – using DNA
comparisons of mutations to estimate
how long two species have been evolving
independently of each other.
Unit 2 Notes
20