Eukaryotic Cells In microbiology

Question 1

Protist

Answer 1

Refer to a diverse group of microscopic eukaryotic organisms who don’t have a shared evolutionary origin.
Protozoa are non photosynthetic motile organisms that are always unicellular

Question 2

Plankton

Answer 2

Microorganisms that drift or float in water moved by currents.
Zooplankton- motile and non photosynthesis
Phytoplankton-photosynthetic

Question 3

Trophozoites

Answer 3

During the feeding and growth part of their life cycle. These feed on small particulate food sources such as bacteria. Some Protozoa exist exclusively in the trophozoite form, others develop to a encapsulated cyst stage when environmental conditions are too harsh for trophozoites.

Question 4

Encystment

Answer 4

Process by which a trophozoite becomes a cyst. A cyst is a cell with a protective wall.

Question 5

Excystment

Answer 5

When conditions become more favorable, these cysts are triggered by environmental cues to become active again.

Question 6

Schizogony

Answer 6

The nucleus of a cell divides multiple times before the cell divides into many smaller cells. The product is called Merozoites and they are stored in the structures known as schizonts.

Question 7

Syngamy

Answer 7

Protozoans produce Haploid gametes that fuse through syngamy

Question 8

Ciliates

Answer 8

A group of protozoan that reproduce through conjugation.

Question 9

Pellicle

Answer 9

All protozoan have a plasma membrane (plasmalemma) and have some bands of protein just inside the membrane that add rigidity forming a structure called the pellicle

Question 10

Ectoplasm

Answer 10

Some protozoan have distinct layers of cytoplasm under the membrane. This is the outer gel layer (with micro filaments of actin)

Question 11

Endoplasm

Answer 11

Sol (fluid) region of cytoplasm in the ectoplasm layer. These structures contribute to complex cell shapes in some protozoan whereas others have more flexible shapes.

Question 12

Cytostome

Answer 12

Those that have a specialized structure for taking in food through phagocytosis

Question 13

Cytoproct

Answer 13

Those that have specialized structure for the exocytosis of wastes.

Question 14

Holozoic

Answer 14

Protozoa that ingest whole food particles through phagocytosis

Question 15

Saprozoic

Answer 15

Ingest small soluble food molecules

Question 16

Pseudopodia

Answer 16

“False feet” to attach the cell to the surface then allow cytoplasm to flow into the extension this moving themselves forward

Question 17

Contractive vacuoles

Answer 17

Organelles that can be used to move water out of the cell for osmotic regulation (salt and water balance)

Question 18

Amoebozoa

Answer 18

The supergroup of protozoan that use amoeboid movement. Actin microfilaments produce pseudopodis into which the remainder of the protoplasm flows thereby moving the organism.

Question 19

E. Histolytica

Answer 19

Medically important, transmitted by cysts in feces and is the primary cause of amoebic dysentery

Question 20

Eumycetozoa

Answer 20

Are a group of organisms called slime molds. Slime molds can be divided into 2 types: cellular slime molds and plasmodia’s slime molds

Question 21

Cellular slime molds

Answer 21

Exist as individual amoeboid cells that periodically aggregators into a mobile slug. The aggregate then forms a fruiting body that produces haploid spores.

Question 22

Plasmodia’s slime molds

Answer 22

Exist as large multi nuclear amoeboid cells that form reproductive stalks to produce spores that divide into gametes.

Question 23

Dictyostelium discoideum

Answer 23

Cellular slime mold that has been an important study organism for understanding cell differentiation because it has both single celled and multicelled life stages with the cells showing some degree of differentiation in the multicelled form.

Question 24

Chromalveolata

Answer 24

This supergroup is united by similar origins of its members plastids and includes the apicomplexans, ciliates, diatoms, and dinoflagellates among other groups.

Question 25

Apicomplexans

Answer 25

Are intra- or extracellular parasites that have an apical complex at one end of the cell. The apical complex is a concentration of organelles, vacuoles, and microtubules that allows the parasite to enter the host cells.

Question 26

Cryptosporidium Pravin

Answer 26

Causes intestinal symptoms and can cause epidemic diarrhea when the cysts Contaminate drinking water

Question 27

Theileria (babesia) microti

Answer 27

Transmitted by the tick causing recurring fever that can be fatal and is becoming a common transfusion transmitted pathogen in the US

Question 28

Toxoplasma Gondi

Answer 28

Causes toxoplasmosis and can be transmitted from cat feces, unwashed fruit and vegetables, or from undercooked meat. Can be associated with serious birth defects, pregnant women need to avoid exposure to car feces.

Question 29

Ciliates

Answer 29

Are large very diverse group characterized by the presence of cilia on their cell surface. Cilia is used for locomotion and often for feeding, some forms are non motile.

Question 30

Micronucleus

Answer 30

In ciliates is diploid, somatic, and used for sexual reproduction by conjugation

Question 31

Macronucleus

Answer 31

In ciliate derived from micronucleus, it becomes polyploid and has a reduced set of metabolic genes.

Question 32

Balantidium Coli

Answer 32

The only parasitic chili ate that affects humans by causing intestinal illness

Question 33

Oomycetes

Answer 33

Also called water molds. We’re once classified with fungi. But they actually differ from fungi. They have cell walls of cellulose and are generally diploid whereas fungi are typically haploid.

Question 34

Excavata

Answer 34

Supergroup including primitive eukaryotes and many parasites with limited metabolic abilities. These organisms have complex cell shapes and structures, often including a depression on the surface of the cell called an excavate.
Includes subgroups fornicata, parabasilia, and evglenozoa

Question 35

Formicata

Answer 35

Lack mitochondria but have flagella. Includes giardia lamblia, a widespread pathogen that causes diarrhea illness and can be spread through cysts from feces that contaminate water supplies

Question 36

Parabasalia

Answer 36

Are frequent animal endosymbionts, they live in the guts of animals like termites and cockroaches. Have basal bodies and modified mitochondria (kiretoplastids). Also have a large complex cell structure with undulating membrane and often many flagella.

Question 37

Trichomonads

Answer 37

Include pathogens such as trichomonas vaginalis, which causes the human sexually transmitted disease trichomoniasis. Doesn’t have Sx in men but they can’t transmit it. Women have vaginal discomfort and discharge and cause complication in pregnancy.

Question 38

Euglenozoa

Answer 38

Are common and include photosynthetic and non photosynthetic species. Typically not pathogenic. Cells have 2 flagella, a pellicle, a stigma (eyespot) to sense light, and chloroplasts for photosynthesis. The pellicle is made of a series of protein bands surrounding the cell, supports the cell membrane and gives cell shape.

Question 39

Algae

Answer 39

Are autotrophic protists that can be unicellular or multicellular. Found in supergroups chromalveolata and archaeplastida. They’re responsible for production of 70% oxygen and organic matter in aquatic environment.

Question 40

Algal blooms

Answer 40

Occur when algae grow quickly and produce dense populations, can produce high concentrations of toxins that impair liver and nervous system diction in aquatic animals and humans.

Question 41

Pyrenoids

Answer 41

Algal cells can have one or more chloroplasts that contain structures, pyrenoids, to synthesize and store starch.

Question 42

Primary chloroplasts

Answer 42

Have 2 membranes. One from the original Cyanobacteria that ancestral eukaryotic cell engulfed and one from the plasma membrane of the engulfing cell.

Question 43

Chromalveolata and archaeplastida

Answer 43

Algae and Protozoa are mixed into these supergroups.

Question 44

Dinoflagellates

Answer 44

Fall within supergroup Chromalveolata. Mostly marine organisms and are an important component of plankton. Have a variety of nutritional types: phototrophic, heterotrophic, or mixotrophic.

Those that are photosynthetic use chlorophyll a and c2, have 2 flagella to whirl. Some have cellular plates (thecca)

Can produce neurotoxins

When population is dense it creates a “red tide” a harmful algal bloom

Question 45

Stramenopiles

Answer 45

Also fall under Chromalveolata. Includes the golden algae (chrysophyta) brown algae (phaecophyta) and diatoms. Have chlorophyll a and c1/c2 and fucoxanthin as photosynthetic pigments.

Diatoms have flagella and frustules? Outer cell walls of crystallized silica

Question 46

Archaeplastids

Answer 46

Include green algae, red algae, and land plants

Question 47

Green algae

Answer 47

Has chlorophyll a and b pigments, cellulose cell walls and starch as a carb. Storage molecule.

Question 48

Chlamydomonas

Answer 48

(Green algae) has a single large chloroplast, 2 flagella, and a stigma (eyespot), important in molecular biology studies

Question 49

Lichen

Answer 49

A combination of two organisms, a green algae or cyanobacterium and a ascomylete fungus, living in a symbiotic relationship. Can be found on rocks or epiphytes ( other plants)

Question 50

Lichen relationship

Answer 50

Mutualistic: fungus obtain photosynthates and algae grow in a drier environment

Question 51

Lichen uses

Answer 51

Used in foods and to extract chemicals as dyes or anti microbial substances or environmental indicators.

Question 52

Lichen structures

Answer 52

Body called thallus, and outer tightly packaged fungal layer called a cortex, and a inner loosely packaged fungal layer called a medulla. They use rhizines to attach to substrate

Question 53

3 major types of lichen

Answer 53

1) crustose lichens - lichen that are tightly attached to substrate giving them a crusty appearance
2) foliose lichens- those that have leaf like lobes, they may only be attached at one point in the growth form, and they also have a second cortex below the medulla.
3) froticose lichens- have rounded structured and an overall branched appearance.

Question 54

Fungi importance

Answer 54

Because they have medical relevance with some pathogenic species that cause mycoses (illness from fungi).
Some are opportunistic, causing infections when the hosts immune defense is compromised and don’t formally cause illness in those healthy.
Act as decomposers and critical for production of certain foods like cheese.
Also major source of antibiotics like penicillins.
Fungi are typically heterotrophic and saprozoic.

Question 55

Hyphae

Answer 55

Most multicellular fungi are made up of filaments called hyphae. They can form a triangles network called mycelium and form thallus (body) of fleshy fungi. They have walls between the cells Called septate hyphae. Hyphae that lack walls and cell membranes between the cells are called nonseptate or coenocytic hyphae.

Question 56

Budding yeast

Answer 56

Yeast are unicellular fungi. Budding yeast reproduce asexually by budding off a smaller daughter cell, the resulting cells may sometimes stick together as a short chain or pseudo hypha.

Question 57

Candida albicans

Answer 57

Is a common yeast that forms pseudohypha. It’s associated with various infections in humans (vaginal yeast, oral thrush, candidiasis of skin)

Question 58

Dimorphic

Answer 58

Some fungi are dimorphic, having more than one appearance during their life cycles. Can appear as yeast or molds, important for infectivity. Can change appearance in response to environmental changes such as nutrients, temperature.

Question 59

Chitin

Answer 59

Fungal cell walls contain chitin as opposed to cellulose. Final membranes have different sterols called ergosterols, which are often exploited as targets for anti fungal drugs.

Question 60

Fungi reproduction

Answer 60

Either through cross or self fertilization. Haploid fungi form hyphae that have gametes at the tips. 2 different mating types (+ or - type) are involved.

Question 61

+ and - type gametes

Answer 61

Cytoplasms of these types gametes fuse (plasmogamy) producing a cell with 2 distinct nuclei (dikaryotic cell). Later the nuclei fuse (karogamy) to create a diploid zygote.
Zygote undergoes meiosis to form spores that germinate to start the haploid stage, which creates more haploid mycelia.
Depending on the taxonomic group the spores are known as zygospores, ascospores, basidiospores.

Question 62

Glomeromycota

Answer 62

Some fungi species have substantial economic impact because of their ability to reduce crop yield.
This species include the mycorrhizal fungi, important symbionts with plant roots that can promote plant growth by acting like an extended root system. The fungi receive carbs from the plant and the plant benefit from increased ability to take up nutrients and minerals from the soil.

Question 63

Chytrids

Answer 63

Are extremely ecologically important. They’re generally aquatic and have flagellated motile gametes, specific types are implicated in amphibian declines around the world.

Question 64

Zygomycota

Answer 64

Mainly saprophytes with coenocytic hyphae and haploid nuclei. Use sporangiospores for asexual reproduction.
Uses zygospores for sexual reproduction have hard walls from fusion of reproductive cells from 2 individuals.

Important for food science and as crop pathogens.

Question 65

Rhizopus stolonifer

Answer 65

A bread mold that causes rice seedling blight.

Question 66

Mucor

Answer 66

Genus of fungi that can cause necrotizing infections

Question 67

Ascomycota

Answer 67

Include fungi used for food (edible mushrooms, morels, and truffles) others cause food spoilage and others are human pathogens.
Have septate hyphae and cup shaped fruiting bodies.

Species in genus aspergillus cause allergy and infection, useful in research and production of fermented alcohol like sake. Can be a contaminate in nuts and stored grains producing aflatoxin.

Some are dermatophytes, pathogenic fungi causing skin infection (athletes foot, ringworm).

Question 68

Basidiomycota

Answer 68

Basidia (club shaped) that produce basidiospores within fruiting bodies called basidiocarps.
Important decomposers and as food.

Question 69

Cryptococcus neoformans

Answer 69

Found as yeast. Cause lung infection when inhaled by weak immune system.

Question 70

Microsporidia

Answer 70

Unicellular fungi, obligate intercellular parasites. Lack mitochondria, peroxisomes, centrioles. Spores release polar tubules that pierce host cell membrane to allow fungi to enter.

Question 71

Parasitic helminths

Answer 71

Are animals that are often included within the study of microbiology because many species of these worms are identified by their microscopic eggs and larvae.
2 major groups: roundworms(nematoda) and flatworms(platyhelminthes)

Question 72

Monoecious

Answer 72

Have both male and female reproductive organs

Question 73

Diecious

Answer 73

Either male or female organs not both.

Question 74

Roundworms (nematoda)

Answer 74

Have a full digestive system. Some are intensional and eggs are identified in feces or around the Amy’s.

Pineorms are the most common in the US females lay eggs at night.
Hookworms (new and old world)
Trichinellosis contracted by eating undercooked meat, release larvae and they encyst into muscles.

Question 75

Flatworms (platyhelminths)

Answer 75

Flukes, schistosomiasis, and tapeworms (cestodes)

Question 76

Flukes

Answer 76

No segmented and have oral suckers. Attach to inner walls of intestines, lungs, large blood vessels, or liver. Babe complex life cycles with multiple hosts.

Question 77

Schistosomiasis

Answer 77

Second most serious parasitic disease. In freshwater snails. Immature form burrows through skin into blood. Migrate to lungs, liver, and other organs. Sx are anemia, malnutrition, abd. Pain, fluid buildup, and death.

Question 78

Tapeworms (cestodes)

Answer 78

Segmented, have suckers or hooks of scolex (head). Attach to wall of small intestine body made up of proglottids that contain repro structures detach when gametes are fertilized releasing gravid proglottids with eggs.

Host consumes egg then they hatch into larval form called oncosphere.
Migrates to a particular tissue or organ in intermediate host, and forms cysticerci.
Develop into adult tapeworm in digestive system
Larvae may migrate to skeletal or smooth muscle.