EukaryotaEukaryota

11 22

33

ProkaryotaProkaryota

Lecture 14: Animal ClassificationLecture 14: Animal Classification

In the five-kingdom system of In the five-kingdom system of classification, the eukaryotes were classification, the eukaryotes were distributed among four kingdoms: distributed among four kingdoms: ProtistaProtista, , PlantaePlantae, , FungiFungi, and , and AnimaliaAnimalia..

Protists are eukaryotes and thus Protists are eukaryotes and thus are much more complex than the are much more complex than the prokaryotes.prokaryotes.

The first eukaryotes were The first eukaryotes were unicellular.unicellular.

eukaryotic and multi-cellular eukaryotic and multi-cellular animals originated from protists.animals originated from protists.

2- Kingdom 2- Kingdom ProtistaProtistaاألولياتاألوليات

((Eukaryotic uni-/multi-cellularEukaryotic uni-/multi-cellular))

Protista (Protista (mostly unicellular eukaryotesmostly unicellular eukaryotes) ranging from uni-celled microscopic ) ranging from uni-celled microscopic members, simple multi-cellular forms, and complex giants like members, simple multi-cellular forms, and complex giants like seaweedsseaweeds البحر البحر حشائش .. حشائش

• Still,“Still,“protistprotist” is used as ” is used as a term for a great diversity of a term for a great diversity of eukaryotic kingdoms.eukaryotic kingdoms.

• Most of the 60,000 known Most of the 60,000 known protists are unicellular, but protists are unicellular, but some are colonial some are colonial مستعمراتمستعمرات and and others multiothers multi--cellular. cellular.

• Many protists form resistant Many protists form resistant cells (cells (cysts cysts حوصلةحوصلة) that can ) that can survive harsh conditions. survive harsh conditions.

ProtistsProtists

A)- NutritionA)- Nutritionالتغذيةالتغذية ::Most protists are Most protists are aerobicaerobic التنفس التنفس هوائية with mitochondria for , with mitochondria for , هوائية

cellular respiration.cellular respiration.Some protists are Some protists are photoautotrophsphotoautotrophs with chloroplasts. with chloroplasts.Still others are Still others are heterotrophsheterotrophs that absorb organic molecules that absorb organic molecules

or ingest larger food particles.or ingest larger food particles.A few are A few are mixotrophsmixotrophs, combining photosynthesis and , combining photosynthesis and

heterotrophic nutrition.heterotrophic nutrition.Protists may include photosynthetic species, heterotrophic Protists may include photosynthetic species, heterotrophic

species, and mixotrophic species.species, and mixotrophic species.

Characters of ProtistsCharacters of Protists األوليات األوليات صفات صفات

B)- MovementB)- Movementالحركةالحركة :: - - Most protists move with flagellaMost protists move with flagellaاألسواطاألسواط or ciliaor ciliaاألهداباألهداب

during some time in their life cycles.during some time in their life cycles. - The eukaryotic flagella are not homologous to those - The eukaryotic flagella are not homologous to those

of prokaryotes.of prokaryotes.

The eukaryotic flagella are extensions of the The eukaryotic flagella are extensions of the cytoplasm with a support of the cytoplasm with a support of the 9 + 2 microtubule 9 + 2 microtubule systemsystem..

Cilia are shorter and more numerous than flagella.Cilia are shorter and more numerous than flagella.Cilia and flagella move the cell with rhythmic power Cilia and flagella move the cell with rhythmic power

strokes, analogous to the oars of a boat.strokes, analogous to the oars of a boat.C)- ReproductionC)- Reproductionالتكاثرالتكاثر :: - Reproduction and life cycles are highly varied- Reproduction and life cycles are highly variedمتنوعمتنوع among protists.among protists. Mitosis occurs in almost all protists. Mitosis occurs in almost all protists. - Some protists are asexual- Some protists are asexualالجنسيةالجنسية .. - Others are primarily asexual but can also reproduce sexually occasionally.- Others are primarily asexual but can also reproduce sexually occasionally.

ProtistsProtists

F)- ImportanceF)- Importanceاألهميةاألهمية ::Many protists are symbiontsMany protists are symbiontsمتطفلةمتطفلة that that

inhabit the body fluids, tissues, or cells inhabit the body fluids, tissues, or cells of hostsof hostsالعائلالعائل ..

These symbiotic relationships span the These symbiotic relationships span the continuum from mutualism to continuum from mutualism to parasitism.parasitism.

Some parasitic protists are important Some parasitic protists are important pathogens of animalspathogens of animals للحيوان للحيوان ممرضات , , ممرضاتincluding those that cause potentially including those that cause potentially fatal diseases in humans.fatal diseases in humans.

ProtistsProtists

G)- Example of Protista:G)- Example of Protista: Systematic PositionSystematic Position التقسيمي التقسيمي الوضع الوضع KingdomKingdom: Protista : Protista األولياتاألوليات Subkingdom: ProtozoaSubkingdom: Protozoa ) عويلم ) مملكة ( تحت عويلم ) مملكة تحت

الحيوانية الحيوانية األوليات األوليات Phylum: Protozoa Phylum: Protozoa األوليات األوليات شعبةشعبة الحيوانيةالحيوانية

Subphylum: MastigophoraSubphylum: Mastigophora شعبة شعبة تحت تحت ) السوطيات) ( شعيبة السوطيات) شعيبة

example: example: EuglenaEuglenaاليوجلينااليوجلينا a singlea single--celled mixotrophic celled mixotrophic الغذاء الغذاء متعدد ,protist, protist متعددcan use chloroplasts to undergo can use chloroplasts to undergo photosynthesisphotosynthesis if if

light is available light is available or live as a or live as a heterotrophheterotroph by absorbing organic by absorbing organic

nutrients from the environment.nutrients from the environment.Reproduce asexually by “Reproduce asexually by “binary fissionbinary fission”. ”. Sometimes Sometimes form resistant cells (form resistant cells (cystscysts) that can ) that can

survive harsh conditions. survive harsh conditions.

Protists (e.g. Protists (e.g. EuglenaEuglena))

سوطسوط

مستشعر مستشعر ضوئيضوئي

فجوة فجوة منقبضةمنقبضة

بالستيدة بالستيدة خضراءخضراء

حبيباتحبيبات

النواةالنواة

الغشاء الغشاء البالزميالبالزمي

أشرطة أشرطة بروتينيةبروتينية

EuglenaEuglena

بقعة بقعة عينيةعينية

1. Protists use flagella (1. Protists use flagella (flagellates) for movement for movement

2-2- Trypanosoma Trypanosomaالتريبانوسوماالتريبانوسوما

TrypanosomaTrypanosoma : is : is symbiotic and include symbiotic and include pathogenic parasites. pathogenic parasites. causes African causes African sleeping sickness.sleeping sickness.Systematic PositionSystematic Position

KingdomKingdom: Protista: ProtistaSubkingdom: ProtozoaSubkingdom: ProtozoaPhylum: ProtozoaPhylum: ProtozoaSubphylum: Subphylum: MastigophoraMastigophoraexample:example: Trypanosoma Trypanosoma It is It is pathogenic parasitepathogenic parasitecauses African sleeping causes African sleeping sicknesssickness

األفريقي النوم األفريقي مرض النوم مرض

3. Parasitic Protists: Protists: Apicomplexans القمة القمة معقدة معقدة

All apicomplexans are parasites of All apicomplexans are parasites of animals and some cause serious human animals and some cause serious human diseases.diseases.The parasites are tiny infectious cellsThe parasites are tiny infectious cells صغيرة صغيرة خاليا خاليا with a (sporozoites) with a complexcomplex of organelles of organelles (sporozoites) ممرضةممرضةspecialized for penetratingspecialized for penetratingاختراقاختراق host cells and host cells and tissues at the tissues at the apexapexقمةقمة of the sporozoite cell.of the sporozoite cell.

Most apicomplexans have life cycles with both Most apicomplexans have life cycles with both sexualsexual and and asexualasexual stages and often require stages and often require two or more different host species for two or more different host species for completion.completion.

PlasmodiumPlasmodium, the parasite that causes , the parasite that causes malaria, spends part of its life in malaria, spends part of its life in mosquitoes and part in humans.mosquitoes and part in humans.

KingdomKingdom: Protista: ProtistaSubkingdom: ProtozoaSubkingdom: ProtozoaPhylum: ProtozoaPhylum: Protozoa2- 2- Subphylum: SporozoaSubphylum: Sporozoaexampleexample: : PlasmodiumPlasmodium

المالريا المالريا بالزموديوم بالزموديوم

Subphylum: Sporozoa Subphylum: Sporozoa البوغياتالبوغيات

الطور الطور المعديالمعدي

الحويصالحويصالت الت

الجرثومالجرثوميةية

الحويصالت الحويصالت البيضيةالبيضية

Subphylum: Subphylum: CiliophoraCiliophoraالهدبياتالهدبيات ,, Protists use cilia Protists use ciliaأهدابأهداب for for movementmovement

The Ciliophora (ciliates), a diverse protist The Ciliophora (ciliates), a diverse protist group, is named for their use of cilia to group, is named for their use of cilia to move and feed.move and feed.

Most ciliates live in freshwater.Most ciliates live in freshwater.Their cilia coordinate movement.Their cilia coordinate movement.

Some ciliates are completely covered by Some ciliates are completely covered by rows of cilia, whereas others have cilia rows of cilia, whereas others have cilia clustered into fewer rows.clustered into fewer rows.

The specific arrangement of cilia adapts the The specific arrangement of cilia adapts the ciliates for their lifestyles.ciliates for their lifestyles.

األهداباألهداب

الفجوة الفجوة الغذائيةالغذائية

الميزاب الميزاب الفميالفمي

النواة النواة الصغيرةالصغيرة

النواة النواة الكبيرةالكبيرة

الفجوة الفجوة المنقبضةالمنقبضة

Subphylum:Subphylum: Ciliophora Ciliophora الهدبيات الهدبيات شعيبة شعيبة

ParameciumParamecium: has cilia along the oral groove: has cilia along the oral groove الميزاب الميزابdraw in fooddraw in food الفميالفمي الغذاء الغذاء يبلع that are engulfed by that are engulfed by يبلعphagocytosis, aphagocytosis, and expelsnd expelsويُخرجويُخرج accumulated water from accumulated water from the contractile vacuolethe contractile vacuole المنقبضة المنقبضة الفجوة .. الفجوة

ParameciumParamecium hashas two types of two types of nuclei, a large nuclei, a large macronucleusmacronucleus and usually and usually several tiny several tiny micronucleimicronuclei..ParameciumParamecium generally reproduce generally reproduce asexuallyasexually

by binary fission of the macronucleus, by binary fission of the macronucleus, rather than mitotic division.rather than mitotic division.

The micronuclei (with between 1 and 80 The micronuclei (with between 1 and 80 copies) are required for sexual processes copies) are required for sexual processes that generate genetic variation.that generate genetic variation.

ParameciumParamecium

4. 4. Subphylum: Subphylum: SarcodinaSarcodinaالسركوديناالسركودينا Protists use pseudopodia Protists use pseudopodia الكاذبة الكاذبة األقدام for movement and feedingfor movement and feeding األقدام

Sarcodina are protists use pseudopodia, Sarcodina are protists use pseudopodia, cellular extensions, to move and often to cellular extensions, to move and often to feed.feed.Most species are heterotrophs that actively Most species are heterotrophs that actively

feed on bacteria and other protists.feed on bacteria and other protists.Other species are symbiotic, including Other species are symbiotic, including

some human parasites.some human parasites.Amoebas are all unicellular and use Amoebas are all unicellular and use

pseudopodia pseudopodia to move and to feed.to move and to feed.• Amoeboid movementAmoeboid movement الحركة الحركة occurs by changes in occurs by changes in األميبيةاألميبيةmicrotubules and microtubules and microfilaments in the microfilaments in the cytoskeleton.cytoskeleton.

• Pseudopodia activity is directed Pseudopodia activity is directed toward food.toward food.

Amoebas inhabit freshwater and marine Amoebas inhabit freshwater and marine environmentsenvironmentsThey may also be abundant in soils.They may also be abundant in soils.

Most species are free-living heterotrophs.Most species are free-living heterotrophs.Some are important parasites. Some are important parasites. These include These include

Entamoeba histolyticaEntamoeba histolytica which which causes amoeboid dysentery causes amoeboid dysentery الدوسنتاريا الدوسنتاريا مرض in in مرضhumans.humans.

These organisms spread These organisms spread byby contaminated drinking contaminated drinking water, food, and eating utensils. water, food, and eating utensils.