Transcript Principals of General Zoology (Zoo-103)

Lecture 13: Animal Classification ‫تصنيف احليوان‬
Systematic/Taxonomy ‫علم التصنيف‬
 Systematic includes taxonomy, which is the naming ‫ تسمية‬and
classification ‫ تصنيف‬of species and groups of species.
 Taxonomy: is that branch of biology dealing with the identification ‫ تعريف‬and
naming ‫ تسمية‬of organisms.
 Aristotle ‫( أرسطو‬ancient Greek philosopher) began the science of taxonomy.
 Carolus Linneus ‫( كارلوس لينياس‬1700s) (Swedish botanist) classified all thenknown organisms into two large kingdoms:
a) Kingdom Plantae ‫المملكة النباتية‬
b) Kingdom Animalia ‫المملكة الحيوانية‬.
 Robert Whittaker in 1969 proposed five kingdoms: Plantae, Animalia, Fungi,
Protista, and Monera.
 Recent studies suggest that three domains be employed: Archaea, Bacteria,
and Eukarya
Animal Taxonomy
 Linneus classified species ‫ النوع‬as the
smallest unit, and that each species nested
within ‫ يندرج تحت‬a higher category
 Species is a Latin word meaning “kind” or
“appearance ‫”الشكل الظاهري‬.
 Differentiation between species based on:
a)- Morphological differences ‫اختالفات شكلية‬
b)- The potential to interbreed ‫ القدرة على التزاوج‬with each
other in nature to produce fertile offspring ‫جيل خصيب‬
Traditional Classification ‫التصنيف التقليدي‬
 Traditional Classification ‫التصنيف التقليدي‬: depends on both
common ancestry ‫ النًّسب‬and the amount of differences
among groups.
 The traditional , dating to Linneaus view, is that birds
have feathers ‫ريش‬, reptiles have scales ‫حراشيف‬, and
mammals have hair ‫شعر‬.
 Linneus placed each of these groups in a separate
class within the Phylum Chordata ‫شعبة الحبليات‬.
Binomial nomenclature ‫التسمية الثنائية‬
)‫(االسم الثنائي للحيوان‬

Linneus developed the concept of binomial
nomenclature, whereby scientists could communicate
clearly.

Under the binomial system, each species is assigned a
two-part latinized name ‫اسم التيني من قسمين‬, (a binomial):
1.
2.
3.
4.
The first part, the genus ‫الجنس‬, is the group to which a species
belongs.
The second part, refers to the species ‫ النوع‬within the genus.
The first letter of the genus is capitalized and both names are
italicized and latinized.
For example, Linnaeus assigned to humans the scientific name
Homo sapiens, which means “wise man”.
Systematic position of human ‫الوضع التقسيمي لإلنسان‬
 Kingdom:
 Phylum:
 Class:
 Order:
 Family:
 Genus:
 Species:
Animalia ‫المملكة الحيوانية‬
Chordata ‫شعبة الحبليات‬
Mammalia ‫طائفة الثدييات‬
Primates ‫رتبة الرئيسيات‬
Hominidae ‫عائلة البشر‬
Homo
‫الجنس البشري‬
sapiens
‫اإلنسان‬
Scientific name: Homo sapiens (The Wise Man ‫)اإلنسان العاقل‬
Three Kingdoms of life
3 Eukaryota
There are three Kingdoms of life"
1)- Bacteria (Eubacteria),
2)- Archaea,
3)- Eukaryota (Fungi, Protesta,
Plantae & Animalia)
1
Viruses are not considered living
organisms.
2
1- Prokaryotes (bacteria & archaea)
 Current taxonomy recognizes
two prokaryotic domains
(Kingdoms): domain Bacteria and
domain Archaea.
 Bacteria and archaea exist so
early in life and are very
different.
 At the same time, they
both are structurally
organized at the
prokaryotic level.
1- Prokaryotes (bacteria & archaea)
 Prokarytes exist in habitats ‫البيئات‬
that are too cold, too hot, too salty,
too acidic, or too alkaline for any
eukaryote.
•
Prokaryotes often interact with
other species of prokaryotes or
eukaryotes with complementary
metabolisms ‫للتكامل األيضي‬.
•
These relationships called (symbiosis ‫ )تبادل المنفعة‬in three types:
1.
Commensalism ‫المعايشة‬: one partner receives benefits ‫ المنفعة‬while
the other is not harmed or helped by the relationship.
2.
Parasitism ‫التطفل‬: one partner, the parasite, benefits at the
expense of the host.
3.
Mutualism ‫تبادل المنفعة‬: both partners benefit from each other.
A)- Archaea
 Archaea are extremophiles,
“‫ ”محب للظروف القاسية‬of extreme
environments and can be classified
into:
a)- Extreme halophiles ‫محب للملوحة‬:
 live in such saline places as the
Great Salt Lake and the Dead Sea.
 Some species require an extremely
salty ‫ شديدة الملوحة‬environment to grow.
b)- Extreme thermophiles ‫ محب للحرارة‬live
in hot environments.
 The optimum temperatures for most
thermophiles are 60 - 80°C.
B)- bacteria
 Bacteria is considered as the most known prokarotes.
 The major bacterial taxa (species) are now accorded kingdom
status by most prokaryotic systematists ‫علماء التصنيف‬.
 Different types of diseases are caused by bacteria including
cholera, many sexually transmissible diseases ‫األمراض الجنسية المعدية‬,
and certain types of food poisoning ‫التسمم الغذائي‬.
 However, more bacteria are beneficial ‫مفيدة‬.
 Bacteria in our intestines ‫ أمعائنا‬produce important vitamins.
 Bacteria recycle CO2 and other chemical elements between
organic matter and the soil and atmosphere.
 Bacteria often live in close association among themselves and
with eukaryotes in symbiotic relationships ‫عالقة تبادل منفعة‬.
Harmful prokaryotes (Pathogenes ‫)املُْمرضات‬
 Some pathogens produce disease by invading
the tissues of the host.
 More commonly, pathogens cause illness by
producing poisons, called exotoxins ‫السموم الخارجية‬
and endotoxins ‫السموم الداخلية‬.
 Pathogenic prokaryotes cause about half of all human
disease.
 The actinomycete that causes tuberculosis is an
example of this source of symptoms.
Beneficial prokaryotes (‫)النافعة‬
 Humans have learned to exploit the diverse metabolic
capabilities of prokaryotes, for scientific research and
for practical purposes.
 Prokaryotes are used to solve environmental
problems.
 Humans also use bacteria as metabolic “factories” for
commercial products ‫المنتجات التجارية‬.
 The application of organisms to remove pollutants
from air, water, and soil is bioremediation ‫ُمنَقٍّيات أحيائية‬