05: A Survey of Eurkaryotic Cells and Microorganisms Flashcards
(44 cards)
1
Q
Eukaryotic Microbes
A
2
Q
Eukaryotic Cell
A
3
Q
Organization of Eukaryotic Cell
A
- Eukaryotic cell
- External structures
- Boundary of cell
- Organelles and other components within the cell membrane
- External structures
- Glycocaly
- Capsules
- Slimes
- Glycocaly
- Boundary of cell
- Cell wall
- Cell/ cytoplasmic membrane
4
Q
Flagella
A
- Locomotor Appendages
- Long, sheathed cylinder containing microtubules in a 9+2 arrangement
- Covered by an extension of the cell membrane
- 10× thicker than prokaryotic flagella
5
Q
Cilia
A
- Locomotor Appendages
- Similar in overall structure to flagella, but shorter and more numerous
- Found only on a single group of protozoa and certain animal cells
- Function in motility, feeding, and filtering
6
Q
Glycocalyx
A
- An outermost boundary that comes into direct contact with environment
- Usually composed of polysaccharides
- Appears as a network of fibers, a slime layer or a capsule
- Functions in adherence, protection, and signal reception
- Beneath the glycocalyx
- Fungi and most algae have a thick, rigid cell wall
- Protozoa, a few algae, and all animal cells lack a cell wall and have only a membrane
7
Q
Which part of the Eukaryotic cell is responsible for contacting the outside environment and signaling between cells?
A. Flagella
B. Cell Wall
C. Glycocalyx
D. Cell Membrane
A
C. Glycocalyx
8
Q
Functions of Internal Structures within the Eukaryotic Cell
A
9
Q
Rough Endoplasmic Reticulum
A
- originates from the outer membrane of the nuclear envelope
- extends in a continuous network through cytoplasm
- rough due to ribosomes
- proteins synthesized and shunted into the ER for packaging and transport
- first step in secretory pathway
10
Q
Smooth Endoplasmic Reticulum
A
- closed tubular network without ribosomes
- functions in nutrient processing, synthesis, and storage of lipids
11
Q
Golgi Apparatus
A
- Modifies, stores and packages protiens
- Consists of a stack of flattened sacs called cisternae
12
Q
Lysosomes
A
- Synthesis and transport machine
- Vesicles containing enzymes that originate from Golgi apparatus
- intercellular digestion of food particles
- protection against invading microbes
13
Q
Vacuoles
A
- Synthesis and transport machine
- Membrane bound sacs containing particles
- digested
- excreted
- stored
14
Q
Phagosomes
A
- Synthesis and transport machine
- Vacuoles merged with a lysosome
15
Q
Mitochondria
A
- Function in energy production and storage (ATP)
- Cristae
- Spherical organelle with an outer membrane and an inner membrane with folds
- Cristae membranes
- hold the enzymes and electron carriers of aerobic respiration
- Divide independently of cell
- Matrix
- DNA and prokaryotic ribosomes are contained in the spaces around the cristae
16
Q
Chloroplasts
A
- Convert the energy of sunlight into chemical energy through photosynthesis
- Found in algae and plant cells
- Thylakoids
- Outer membrane covers inner membrane folded into sacs stacked into grana.
- Carry pigments (chlorophyll and others)
- Primary producers of organic nutrients for other organisms
17
Q
The Eukaryotic organelle that is responsible for transporting vesicles inside the cells is the
A. Golgi
B. Smooth Endoplasmic Reticulum
C. Rough Endoplasmic Reticulum
D. Nucleus
A
A. Golgi
18
Q
Kingdom Fungi
A
- Majority are unicellular or colonial
- few have cellular specialization
- 100,000 species divided into 2 groups:
- Macroscopic fungi (mushrooms, puffballs, gill fungi)
- Microscopic fungi, with two morphologies
- Hyphae – long filamentous fungi or molds
- Yeast – round ovoid shape, asexual reproduction
19
Q
Hyphae
A
- Long, threadlike cells that make up the bodies of filamentous fungi, or molds
- Some present various textures of mycelia
- Array of color differences macroscopically due to spores
20
Q
Yeasts
A
- Cell distinguished by
- round to oval shape
- mode of asexual reproduction
- Presents a cell wall
- lacks locomotor organelles
- It grows swellings on its surface called buds
- which then become separate cells
21
Q
Yeasts
A
- Some form a pseudohypha, a chain of yeasts formed when buds remain attached in a row
- Because of its manner of formation, it is not a true hypha like that of molds
22
Q
Filamentous Fungi (molds)
A
- cottony, hairy, or velvety texture
- Woven intertwining mass of hyphae called mycelium;
- may be divided by cross walls (septa)
- Vegetative hyphae – digest and absorb nutrients
- Reproductive hyphae – produce spores for reproduction
23
Q
Sporangiospores
A
- Asexual Spore Formation
- Sporangium
- formed by successive cleavages within a saclike head
- Spores initially enclosed but released when the sporangium ruptures.
24
Q
Conidiospores (conidia)
A
- Asexual Spore Formation
- Free spores not enclosed by a spore-bearing sac
25
Sexual Spore Formation
* Spores are formed following fusion of two different strains and formation of sexual structure
* Zygospores
* ascospores
* basidiospores
* Sexual spores and spore-forming structures are one basis for classification
26
Fungal Classification
Kingdom Eumycote
* subdivided into several phyla based upon the type of sexual reproduction:
* Phylum Zygomycota
* zygospores; mostly sporangiospores and some conidia
* Phylum Ascomycota
* ascospores; conidia
* Phylum Basidiomycota
* basidiospores; conidia
* Phylum Chytridomycota
* flagellated spores (Effects frogs)
* Fungi that produce only Asexual Spores (Imperfect)
27
Phylum I
Zygomycota
* Sexual spores: zygospores
* Asexual spores: mostly sporangiospores, some conidia
* Hyphae are usually nonseptate. If septate, the septa are complete
* Most species are free-living saprobes; some are animal parasites
* Can be obnoxious contaminants in the laboratory, food spoilage agents, and destructive to crops
* Examples of common molds:
* Rhizopus, a black bread mold
* Mucor
* Absidia
* Circinella
28
Phylum II
Ascomycota
* Sexual spores: most produce ascospores in asci
* Asexual spores: many types of conidia, formed at the tips of conidiophores
* Hyphae with porous septa
* By far the largest phylum.
* Macroscopic mushrooms to microscopic molds
* yeasts
29
Phylum II
Ascomycota Examples
* *Penicillium:* one source of antibiotics
* *Aspergillus:* common airborne mold that may be involved in respiratory infections and toxicity
* *Candida pseudohyphae:* yeast used in making bread and beer
* *Pneumocystis (carinii) jirovec*i: pathogen of AIDS patients
* *Histoplasma:* cause of Ohio Valley fever
* *Trichophyton:* cause of ringworm
* *Coccidioides immitis:* cause of Valley fever;
* *Candida albicans:* cause of various yeast infections
* *Stachybotrys:* toxic mold
30
Phylum III
Basidiomycota
* Many members are familiar macroscopic forms
* mushrooms and puffballs
* number of microscopic plant pathogens
* rusts and smuts
* attack and destroy major crops
31
Phylum IV
Chytridimycota
* Members of this phylum are unusual, primitive fungi commonly called chytrids.
* cellular morphology ranges
* single cells to clusters and colonies
* They generally do not form hyphae or yeast-type cells
* presence of special flagellated spores
* zoospores and gametes.
* Most chytrids are saprobic and free-living in soil, water, and decaying matter.
* Not known to cause human disease
* Known to be serious frog pathogens
32
Roles of Fungi
Adverse Impact
* Mycoses
* allergies
* toxin production
* Destruction of crops and food storages
33
Roles of Fungi
Beneficial Impact
* Sources of antibiotics
* alcohol
* organic acids
* vitamins
* Decomposers of dead plants and animals
* Used in making foods
* genetic studies
34
Fungi are generally classified according to their
A. Type of sexual spore
B. Type of asexual spore
C. Type of hyphae
D. Type of habitat
C. Type of hyphae
35
Algae
* eukaryotic organisms
* usually unicellular and colonial
* photosynthesize with chlorophyll
36
Protozoa
* unicellular eukaryotes
* lack tissues
* share similarities
* cell structure
* nutrition
* life cycle
* biochemistry
37
Algae
* Photosynthetic organisms
* Microscopic forms are unicellular, colonial, filamentous
* Macroscopic forms are colonial and multicellular
* Contain chloroplasts with chlorophyll and other pigments
* Cell wall
* May or may not have flagella
* Most are free-living in fresh and marine water – plankton
* Provide basis of food web in most aquatic habitats
* Produce large proportion of atmospheric O2
* Dinoflagellates can cause red tides and give off toxins that cause food poisoning with neurological symptoms
38
Protozoa
* Diverse group of 65,000 species
* Vary in shape, lack a cell wall
* Most are unicellular; colonies are rare
* Most are harmless, free–living in a moist habitat
* Some are animal parasites and can be spread by insect vectors
* All are heterotrophic–lack chloroplasts
* Cytoplasm divided into ectoplasm and endoplasm
* Feed by engulfing other microbes and organic matter
* Most have locomotor structures–flagella, cilia, or pseudopods
* Exist as trophozoite–motile feeding stage
* Many enter a dormant stage during unfavorable conditions for growth and feeding–cyst
* All reproduce asexually, mitosis or multiple fission; many also reproduce sexually– conjugation
39
Pathogenic flagellates:
Trypanosomes
* Genus *Trypanosoma*
* T. brucei – African sleeping sickness
* T. cruzi – Chaga’s disease
* Long, crescent-shaped cells with a single flagellum
* Occur in the blood during infection
* Transmitted by blood-sucking vectors
40
Infective amoebas:
Entamoeba
* *Entamoeba histolytica* – amebic dysentery
* Ingested cysts germinate in the small intestine
* Trophozoites migrate to the large intestine and grow
* They can invade the liver, lungs, and skin
* Common symptoms include gastrointestinal disturbances
41
Parasitic Helminths
* Multicellular animals, organs for reproduction, digestion, movement, protection
* Parasitize host tissues
* Have mouthparts for attachment to or digestion of host tissues
* Most have well-developed sex organs that produce eggs and sperm
* Fertilized eggs go through larval period in or out of host body
42
Flatworms
* flat, no definite body cavity
* digestive tract a blind pouch
* simple excretory and nervous systems
* Cestodes (tapeworms)
* Trematodes or flukes
* flattened, nonsegmented worms with sucking mouthparts
43
Roundworms (nematodes)
* round
* complete digestive tract
* protective surface cuticle
* spines and hooks on mouth
* excretory and nervous systems poorly developed
44
Parasitic helminths reproduce by:
A. Cysts
B. Spores
C. Eggs and sperm
D. All of the above
C. Eggs and sperm
