Branches of Biology The many levels at which life can be studied include molecules cells organisms populations of a single organism communities of populations living in the same area and the biosphere Chapter 13 Key Concept ID: 562919
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Slide1
Levels of Organization OverviewSlide2
Branches of Biology
The many levels at which life can be studied include molecules, cells, organisms, populations of a single organism, communities of populations living in the same area, and the biosphere. (Chapter 1-3: Key Concept
p
. 20; Page 21 has a Levels of Organization Chart)Slide3
Levels of Organization
Key Concept page 192
The levels of organization in a multicellular organism are individual cells, tissues, organs, and organ systems. These levels of organization can be found on page 193 Figure 7-23.Slide4
Levels of Organization from Atom to Organism
Atom- basic unit of matter
Molecule- group of atoms; smallest unit of most chemical compounds
Organelle- any of a number of organized or specialized structures within a living cell
Cell- smallest unit of life
Tissue- a group of similar cells that perform a particular function
Organ- group of tissues that work together to perform closely related functions.
Organ systems- group of organs that work together to perform closely related functions
Organism- individual living thing Slide5
Levels of Organization in the BodySlide6
Levels of Organization- Population EcologySlide7
Levels of Organization- Population Ecology
Species- group of similar organisms that can breed and produce fertile offspring
Population- group of organisms of one type that live in the same area
Community-populations that live together in a defined area
Ecosystem- community and its nonliving surroundings (biotic and abiotic factors)
Biome- a group of ecosystems that have the same climate and similar dominant communities
Biosphere- the part of Earth that contains all ecosystems; the highest level of organization that ecologists studySlide8
Population Ecology Levels of OrganizationSlide9
Other types of organization in science are classification and taxonomy
Classification is a very broad term which simply means putting things into groups based on similarities.
Taxonomy means giving names to things.Slide10Slide11
Classification
Why classify?
To study the diversity of life, biologists use a classification system to name organisms and group them in a logical sense.
TAXONOMY!
Taxonomy
-Science of classifying organisms and assigning each organism a universally accepted name
.
By using a scientific name, biologists can be certain that everyone is discussing the same organism.
When the classify organisms, they organize them into groups that have biological significances. Slide12
Taxonomy
Science often requires smaller categories as well as larger more general categories.
In a good system of classification, organisms places into a particular group are more similar to each other than they are to organisms in other groups.
When taxonomists classify things, they use not only one but several characteristics to group organisms.
Taxonomists compare structure of modern-day life forms with those found in fossils.
Taxonomists also use information from biochemical analyses of organisms to compare and classify species. Slide13
Assigning scientific names
Common names vary among languages and even among regions within a single country.
Aristotle developed the first method of classification.
Species are classified on their similarities in structure, chemistry, and behavior.
Closely related species have similar DNA, and, therefore, similar proteins.
Sometimes behavioral patterns help taxonomists classify an organism. Slide14
Animal ClassificationSlide15
Linnaean Classification System
Created by Carl Linnaeus (1707-1778)
Before Linnaeus, organisms were classified based on their type of locomotion and physical characteristics
Problem? Names were too long, and people describe things differently.
Utilizes
binomial nomenclature-
a
two name
system (genus and species
)
Ex:
Homo sapiensSlide16
Scientific Name
First name is
the genus to which the organism
belongs.
Second
name
is
unique to each species within the genus.
Often Latinized description of some imperfect trait of the organism of where the organism lives.
3 Rules For Scientific Name
Italicized or underlined
Genus name is Capitalized
Species name is lower-case
Example:
Tursiops
truncatusSlide17
The 8 Taxonomic ranks. All living things have 8 names.
1)
Domain – Did
2)
Kingdom - King
3)
Phylum - Phillip
4)
Class – Come
5) Order - Over
6)
Family - For
7)
Genus - Good
8)
Species – SpaghettiSlide18Slide19
The Modern Classification System
Kingdom
Phylum
Class
Order
Family
Genus
Species
Largest taxonomic group consisting of closely related phyla.
A group of closely related classes.
A group of similar orders.
A group of similar families.
A group of genera that share many characteristics.
A group of closely related species, first part of the scientific name in binomial nomenclature.
A group of similar organisms that can breed and produce fertile offspring. Slide20
Human Taxonomic Classification
-Domain - Eukarya
-Kingdom -
Animalia
-Phylum - Chordata
-Class -
Mammalia
-Order -
Primatdae
-Family -
Hominidae
-Genus - Homo
-Species –
sapien
Subspecies -
sapienSlide21
Evolutionary Classification
Biologists now group organisms into categories that represent lines of evolutionary descent, not just physical similarities.
Evolutionary relationships are revealed by using structure, chemistry, and behavior for classification.
In other words, species placed within the same genus should be more closely related to one another than to species of any other genus.
Genera placed within a family should be more closely related to one another than to members of any other family. The same is true of all of the taxonomic levels, including kingdoms.
This strategy of grouping organisms together based on their evolutionary history is called evolutionary classification. Slide22
Phylogeny
The phylogeny of a species is its evolutionary historyPhylogenetic classification is useful because organisms belonging to the same group will chare certain characteristics.
Even though adults of certain species appear different, the larval stage of one species may resemble the adult stage of another. Slide23
Dichotomous Keys
Dichotomous key: A tool that allows the user to determine the identity of items in the natural world.
Based on characteristics and uses process of comparison and elimination.
Classification uses…
Homology – Similarities between organisms
Adapted traits may further subdivide species into subspecies.