Introduction to Eukaryotes (copy)

characteristics of eukaryotes

1. have a nucleus

2. have membrane-bound organelles

3. more complex and larger than prokaryotes

nucleus

consists of nuclear envelope, chromatin and nucleolus

nuclear envelope

membrane enclosing the nucleus

• protein-lined pores allow material to move in and out

chromatin

DNA + associated proteins

nucleolus

condensed region where ribosomes are formed

peroxisome

metabolizes waste

cytoskeleton

network of microtubules, intermediate filaments, microfilaments that maintain cell shape

centrosome

microtubule-organizing center

microtubules

1. form mitotic spindle

2. maintain cell shape

intermediate filaments

protein fibers that hold organelles in place

microfilaments

fibrous proteins that form the cellular cortex

lysosome

digests food (proteolytic digestion)

rough endoplasmic reticulum (ER)

1. associated with ribosomes

2. makes secretory and membrane proteins

smooth endoplasmic reticulum (ER)

makes lipids

golgi apparatus

modifies proteins

mitochondria

produces energy (ATP)

vacuole

sac which acts as storage area

cytoplasm

jelly-like fluid that organelles are suspended in

difference between the nucleus of prokaryotes and eukaryotes

Eukaryotes have a true nucleus (nuclear membrane + nucleoli), while prokaryotes have no nuclear membrane or nucleoli.

difference between ribosomes of prokaryotes and eukaryotes

Prokaryotes contain smaller-sized ribosomes (70S), while eukaryotes contain 80S and 70S ribosomes.

difference between chromosome (DNA) in prokaryotes and eukaryotes

Prokaryotes have a single, circular chromosome and lack histones. Eukaryotes have multiple, linear chromosomes with histones arrangement.

eukaryotic appendages

1. flagella

2. cilia

   • may or may not be present

flagella

long appendages present singly or in groups that move cell through a whip-like motion

composition of flagella

1. tubulins

2. microtubules

How are cilia different from flagella?

1. shorter

2. more numerous

3. move more rapidly

chloroplast

chlorophyll-containing organelle found in phototropic eukaryotes

T/F: Chloroplast are not readily visible with a light microscope.

False: Chloroplasts are relatively large and readily visible with a light microscope.

composition of chloroplast

1. two phospholipid bilayer membranes

2. 70S ribosomes + DNA

thylakoid

series of flattened membrane discs that contain chlorophyll and other components needed for photosynthesis

endosymbiosis

process where one prokaryote lives inside the cell of another organism to the benefit of both

endosymbiosis hypothesis/theory

Mitochondria and chloroplasts are thought to have evolved from bacteria that were engulfed by larger cells.

primary endosymbiosis

when a bacterium is engulfed by another free-living organism

secondary endosymbiosis

when the product of primary endosymbiosis is engulfed and retained by another free-living eukaryote

• led to extreme diversity in algae and eukaryotes

six biological kingdoms

1. plantae

2. fungi

3. animalia

4. protista

5. bacteria

6. archaea

parasite

an organism that lives on or within a host organism

• gets its food from or at the expense of its host

three main classes of parasites

1. protozoa

2. helminths

3. ectoparasites

general features of protozoa

1. unicellular

2. animal-like

3. motility

4. anaerobic

5. form cysts

How do protozoa feed?

1. phagocytosis or pino

2. enter via specialized site/structure

reproductive strategy of protozoa

binary fission (asexual reproduction)

general features of protista

1. eukaryotic

2. unicellular

3. microscopic or macroscopic

How do protista feed?

1. heterotrophic

2. phototropic

3. combination

environments for protista

1. aquatic

2. terrestrial

3. suitable hosts (if parasites)

reproductive strategies of protista

1. binary fission

2. multiple fission

3. sexually by conjugation

classification of protista

1. animal-like

2. plant-like

3. fungi-like

animal-like protista

1. Sarcodinians

2. Ciliaphora

3. Zooflagellates

4. Sporozoa

Sarcodinia

free living protists that inhabit aquatic and soil environments

locomotion strategy of Sarcodinia

pseudpodia

mode of nutrition of Sarcodinia

phagocytosis on bacteria, other protists, and organic materials

entameoba

parasites of vertebrates and invertebrates

• type of Sarcodinia

How are Entamoeba transmitted?

forms cysts

• person to person

What disease is caused by Entamoeba histolytica?

amoebic dysentery

• example of entamoeba

What disease is caused by Naegleria spp.?

primary amoebic meningoencephlitis

• example of entamoeba

What disease is caused by Acanthamoeba spp.?

keratitis

• example of entamoeba

general features of Ciliophora

1. complex, unicellular

2. defined shape

3. 2 nuclei

locomotion strategy of Ciliophora

cilia

reproductive strategy of Ciliophora

1. binary fission (asexually)

2. sexually by conjugation

general features of Zooflagellates

1. lack plastids

2. reduced mitochondria (anaerobic)

3. lack key enzymes

types of Zooflagellates

1. Diplomonads

2. Parabasalids

3. Euglenoids

4. Kinetoplastids

general features of Diplomonads

1. 2 nuclei

2. multiple flagella

example of Diplomonad

Giardia

• intestinal giardiasis

general features of Parabasalids

1. flagella

2. undulating membrane

3. may have gene from bacteria

example of Parabasalid

Trichomonas

• sexually transmitted

general features of Euglenoids

1. anterior pocket

2. 1 or 2 flagella

mode of nutrition for Euglenoids

1. heterotrophic

2. autotrophic

3. mixotrophic

example of Euglenoid

Euglena

general features of Kinetoplastids

1. 1 flagella

2. single large mitochondria associated with kinetoplast

examples of Kinetoplastids

1. Trypanosoma

2. Leishmania

general features of Sporozoa

1. have apical complex and apicoplast

2. parasitic for humans and animals

3. multiple life stages

apicoplast

non-photosynthetic plastid

reproductive strategy of Sporozoa

1. asexual reproduction

2. sexual reproduction

How are Sporozoa transmitted?

vector transmitted

• require 2+ different hosts

examples of Sporozoa

1. Plasmodium (malaria)

2. Cryptosporidium

3. Toxoplasma (toxoplasmosis)

Plasmodium spp. causes which disease?

malaria

vector of Plasmodium spp.

Anopheles mosquito

Leishmania spp. causes which disease?

visceral, cutaneous and mucocutaneous leishmaniasis

vector of Leishmania spp.

sand fly

Trypanosoma causes which diseases?

1. African trypanosomiasis

2. American trypanosomiasis/Chagas disease

vector of African Trypanosomiasis

Testse fly

vector of Chagas disease

Reduviid bug

Toxoplasma gondii causes which disease?

neonatal toxoplasmosis

How is Toxoplasma gondii transmitted?

ingestion of oocytes

plant-like protists

1. green algae

2. red algae

general features of green algae

1. contain beta carotene, xanthophylls, Chlorophyll A and B

2. cellulose cell wall

3. microscopic or macroscopic

4. unicellular or multicellular

5. motile or non-motile

How do green algae store food?

in the form of starch

environments of green algae

1. freshwater

2. soil

3. symbionts

4. layers near rock surfaces

general features of red algae

1. contains phycoerythrin, phycocyanin, Chlorophyll A

2. eukaryotic

3. mostly multicellular

4. double cell walls

What are the double cell walls of red algae made of?

1. agarose

2. agaropectin

reproductive strategy of red algae

1. asexual reproduction

2. sexual reproduction

general features of metazoan parasites

1. eukaryotic

2. multicellular

3. spend most/all of their lives in the host

4. possess bilateral symmetry, head, tail and tissue differentiation

What are metazoan parasites generally called?

helminths

classification of helminths

1. Nemathelminths (roundworms)

2. Platyhelminths (flatworms)

class of Nemathelminths (roundworms)

Class Nematoda (nematodes)

classes of Platyhelminths (flatworms)

1. Class Trematoda (Trematodes “flukes”)

2. Class Cestoda (Cestodes “tapeworms”)

general features of Nematodes (roundworms)

1. appear round in cross section (cylindrical bodies)

2. complete digestive tract

3. body covered with cutical

4. oral opening may have hooks or suckers

examples of tissue nematodes

1. Toxocara

2. Trichinella

How is Toxocara transmitted?

ingestion of embryonated eggs from dog or cat feces

How is Trichinella transmitted? (causes Trichinosis)

consumption of infected and unfrozen or poorly cooked meat

examples of filarial nematodes

1. Onchocerca

2. Wuchereria and Brugia

How is Onchocerca transmitted?

black fly

symptoms of Onchocerca

1. visual impairment

2. severe itching of the skin