Chapter 29 Flashcards
Bacteria that live within other cells and perform specific functions for their host cell
Endosymbiotic bacteria
Name two supporting evidences for the endosymbiotic theory
Both mitochondria and chloroplasts both contain their own DNA
Both replicate by binary fission not mitosis which supports their bacterial origin
Unlike plants, fungi, and animals protists are not ___
monophyletic
Protist cell surfaces are very diverse. Name 2 mentioned in the text
Amoebas - surrounded by plasma membrane
Diatoms -glassy shell
Protist movement is chiefly by ___ or ____
flagellar rotation
pseuopods
Protists that ingest visible particles of food by pulling them into intracellular vesicles called food vacuoles or phagosomes
Phagotrophs
Protists that ingest food in soluble form are called
osmotrophs
Protists that are both phototrophs and heterotrophs
mixotrophs
Asexual reproduction of protists involves ____ but often the nuclear membrane remains intact.
mitosis
When a cell splits into two halves after mitosis. Usually the daughter cell is smaller but later grows to full size
budding
When cell division is preceded by several nuclear divisions. This allows cytokinesis to produce several individuals almost simultaneously
schizogony
Some protists reproduce by the union of two haploid cells
Sexual reproduction
The great advantage of multicellularity is
it fosters specialization
___, ___, and ___ are grouped as Excavata based on cytoskeletal and DNA sequence similarities showing evolutionary relatedness. Most have a groove on the side of their bodies used for feeding.
Diplomonads
Parabasalids
Euglenozoans
Unicellular move with multiple flagella Lack mitochondria Have two nucleii Example is Giardia
Excavata: Diplomonads
Some live in the guts of termites and digest cellulose
Another example is the protist that causes the STD Trichomonas vaginalis
Have undulating membranes for locomotion
Lack mitochondria
Flagellated
Excavata: Parabasalids
Possess mitochondria
Some have chloroplasts others are heterotrophs
Some have the ability to become heterotrophs in the absence of light
Contain a pellicle
Reproduction occurs by mitosis
Excavata: Euglenozoa: Euglenids
Interlocking proteinaceous strips arranged in a helical pattern form a flexible structure
Pellicle
Two flagella are attached, one is long and has a row of fine hairs along one side. A second shorter flagellum is located within the cell’s reservoir. Contains contractile vacuoles. Contains a light sensitive stigma that helps it move towards light. Contain many small chloroplasts.
Excavata: Euglenozoa: Euglena
- single mitochondria in each cell that contains two types of DNA
- example is Trypanosome which causes sleeping sickness and Chagas disease
Excavata: Euglenozoa: Kinetoplastids
Alveolates include ___, ___, and ____ all of which have a common lineage but diverse modes of locomotion
Dinoflagellates
Apicomplexans
Ciliates
A second branch of Chromalveolates is the _____ including Brown Algae, Diatoms, and Oomycetes
Stramenopila
- most are photosynthetic
- two flagella
- live in marine and fresh water
- encased in plates made with silica
- have chlorophylls a and c and carotenoids
- ex) red tide
- reproduce mainly asexually but can reproduce sexually under starvation
Chromalveolata: Stramenopila: Dinoflagellates
- Spore-forming parasites of animals
- have a unique arrangement of fibrils, microtubules, vacuoles, and organelles at one end of the cell
- Example is Plasmodium which causes malaria
Chromalveolata: Alveolata: Apicomplexans
Ciliates have a ____, a tough but flexible outer covering that enables them to squeeze through or move around obstacles
pellicle
Divide by mitosis and are essential for the physiological function of the well known ciliate Paramecium
Macronucleus
Used in ciliates for sexual reproduction
Micronucleus
Like most ciliates, Paramecium undergoes sexual reproduction known as
conjugation
- photosynthetic
- unicellular
- double shells made of opaline silica
- chlorophyll a, c, and carotenoids
Chromalveolata: Stramenopila: Diatoms
- Either a parasite or saprobes
- Motile spores called zoospores with two unequal flagella
- found in water and have terrestrial relatives
- ex) Phytophthora infestans which caused the potato famine
Chromalveolata: Stramenopila: Oomycetes
- No flagella
- Have both haploid and diploid life phases
- Used as a thickener for ice cream and cosmetics
- Commonly called red algae
Archaeplastida: Rhodophyta
- Lineage of green algae
- Have an extensive fossil record
- Chlorophylls a, b, and carotenoids
Archaeplastida: Chlorophytes
- Unicellular chlorophytes
- two flagella at the anterior end
- haploid
- reproduce asexually and sexually
- able to retract its flagella and settle as an immobile organism if its habitat dries out
Archaeplastida: Chlorophytes: Chlamydomonas
a hollow sphere made up of a single later of 500-60000 cells each having two flagella. Only a small number of the cells are reproductive.
Archaeplastida: Chlorophytes: Volvox
A multicellular chlorophyte that has identical gametophyte and sporophyte generations that consist of flattened sheets two cells thick.
Archaeplastida: Chlorophytes: Ulva
Evidence from rRNA and DNA sequences favors ___ as the green algal clade most closely related to land plants
Charophytes
Use pseudopods for locomotion but are distinct from the Amoebozoans
Rhizaria
- Secrete glassy exoskeletons made of silica
- Unicellular
- Radial or bilateral symmetry
Rhizaria: Radiolarians
- Heterotrophic
- Marine protists
- Resemble tiny snails
- Responsible for lime stone deposits
- Their small shells are called tests
- Have small cytoplasmic projections called podia
Rhizaria: Foraminifera
- Primarily soil protists
- Rely on flagella or pseudopods
- May have ingested a green alga as recently as 60MYA
Rhizaria: Cercozoa
- Move using a pseudopod
- Found in soil and fresh water
- Few are human pathogens
Amoebozoa: Amoebozoa
A non-walled multinucleate mass of cytoplasm that resembles a moving mass of slime
Plasmodium
The structure in which spores of Plasmodium are porduced
sporangium
Fungi and animals are more closely related to each other than to plants because they share a common ancestor which leads them to be grouped as
Opisthokonta
