1. Classifying Organisms

2. Finding Order in Diversity
Biology is divided into different fields because of the wide diversity of organisms.
There are about 1.5 million species identified
There are between 2 and 100 million additional species that have not yet been discovered.
You’ve probably heard of different branches of biology – botany, zoology, herpetology, entomology, etc. Biology is divided into different fields because there is 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 million and 100 million additional species that have not yet been discovered! That’s a lot of different organisms!

3. Finding Order in Diversity
Biologists use a classification system to name and group organisms in a logical manner.
Why isn’t it good enough to use common names of organisms?
With so many organisms out there, you can imagine how hard it would be to keep up with all of them. Biologists us a classification system to name organisms and group them in a logical manner. Why can’t we just use common names of organisms? (Pause) Well, common names vary from place to place. Sometimes there are even several different kinds of organisms that share the same common name in different parts of the country or the world. For instance, salamanders are small amphibians that sort of look like slimy lizards. However, when I was a little girl, my dad said he was going to trap the salamanders that were messing up our yard. What he was really trapping were gophers – small mammals that dig around under the ground and leave tunnels and holes. You can see how confusing it would be to use only common names!

4. Finding Order in Diversity
Taxonomy – discipline of classifying organisms and giving each a universally accepted name
Binomial nomenclature - introduced by Carolus Linnaeus, an 18th-century Swedish botanist.
There’s a special branch of biology that deals only with naming and classifying organisms. It’s taxonomy – the discipline of classifying organisms and giving each a universally accepted name. Currently, we use a system called binomial nomenclature. Bi means 2, nomen is the Latin word for name, clature refers to a system or process. So, binomial nomenclature means a two name naming system. Our system was introduced by Carolous Linnaeus, an 18th century Swedish botanist.

5. Binomial Nomenclature
Two-part scientific name
Italics
First name capitalized
Second name lower case.
Linnaeus’s system is hierarchical (made up of levels).
In our system of binomial nomenclature, each species is assigned a two part scientific name. The name is always written in italics, or underlined if you’re writing it. The first name (the genus name) is always capitalized, the second name is in lower case. There are several more levels in the naming system. After all, we need both small, specific categories and large, general categories. Linnaeus’s system is what we call hierarchical, or made up of multiple levels.

6. Linnaeus’s System
Kingdom
Phylum
Class
Order
Family
Genus
Species

7. Linnaeus’s System Grizzly bear Black bear Giant panda Red fox
Abert squirrel
Coral snake
Sea star
KINGDOM Animalia
PHYLUM Chordata
CLASS Mammalia
ORDER Carnivora
FAMILY Ursidae
GENUS Ursus
SPECIES Ursus arctos
Here’s the Linnaean classification of the grizzly bear. This time we’ll start from the top down. Notice all the different animals shown are members of kingdom animalia. There are others we could include, like insects. When you move to the phylum level, the sea star is eliminated, because sea stars don’t have a backbone. Class mammalia includes all the animals shown except the coral snake. Can you imagine a snake with hair? Order carnivora leaves out the squirrels, which are plant eaters. Family ursidae includes only the bears – so long, Mr. Fox! The genus ursus includes the grizzly and the black bear, but not the panda. And, finally, species Ursus arctos includes only the grizzly bear. The most important thing to remember here is that the more categories 2 organisms share, the more closely related they are. The most closely related ones are members of the same genus – like the dog and the coyote!

8. Evolutionary Trends
Animalia Phyla

9. Invertebrates vs. Vertebrates
95% of all species of animals are invertebrates
Other 5% of animals are vertebrates
Fishes, amphibians, reptiles, birds, and mammals

11. Cephalization
Cephalization - concentration of sense organs & nerve cells at the front end of the body
In general, the more complex an animal is, the more pronounced is their cephalization (head formation) 

12. Kingdom Animalia
General Information

13. Multicellular & Eukaryotic Organisms
Cells lack cell walls & are specialized to carry out different functions
Groups of specialized cells form tissues, which form organs and organ systems

14. Multicellular & Eukaryotic Organisms
Most animals have 4 types of tissues:
Epithelial
Muscular
Connective
Nervous

15. 7 Essential Functions 1. Feeding – HETEROTROPHIC Herbivores
Carnivores
Omnivores
Detritivores
Filter Feeders

16. 7 Essential Functions 2. Respiration
All animals respire (take in oxygen and give off carbon dioxide)
Gas exchange methods range from simple diffusion to complex tissues/organs

17. 7 Essential Functions 3. Circulation
Transport oxygen, nutrients, and waste among an animal’s cells
Small aquatic animals rely on diffusion
Larger animals have a circulatory system
Open C.S. - blood is pumped through a series of sinuses or cavities and comes in direct contact with tissues
Closed C.S. - blood is always contained within vessels

18. Open or closed circulatory system?
How do you know?

19. 7 Essential Functions 4. Excretion
Most animals have an excretory system to eliminate or neutralize ammonia (a primary waste product of cells)
Excretory systems vary from cells that pump water out of the body to complex structures like kidneys

20. 7 Essential Functions 5. Response
Animals respond to stimuli using nerve cells
Nervous systems are present in most animals
Simple nervous systems - networks of nerve cells
Complex nervous systems - include a brain which directs the whole organism

21. 7 Essential Functions 6. Movement
Sessile – attached to a surface; have muscles or muscle-like tissues that allow some movement – feeding by pumping water through the body
Motile – free to move by muscle contractions

22. Sessile or motile?
a. b.

23. 7 Essential Functions 7. Reproduction
Sexually – through the combining of haploid gametes
Creates and maintains genetic diversity in populations
Improves the ability to adapt to environmental changes
Asexually – through budding or fission

24. Early Development
Zygote
Blastula
Blastopore
Protostome
Deuterostome

25. Body Cavity
Acoelomate
Pseudocoelomate
Coelomate
Coelom

26. Symmetry Asymmetry – no apparent symmetry Bilateral Symmetry
Radial Symmetry
Bilateral Symmetry
Planes of symmetry
Plane of symmetry
Ventral side
Dorsal side
Posterior end
Anterior end
Asymmetry – no apparent symmetry