micro lab exam 1

scolex of echinoccocus

Knob-like anterior end of a tapeworm; has suckers and hook-like parts that serve as organs of attachment to the host on which the tapeworm is parasitic

What are pure cultures?

Source with only ONE species of bacteria

trypanosoma

Structure: unicellular movement: motile location: in blood disease: -causes African sleeping sickness. -in US= Chagas disease

when should you flame sterilize your inoculating Loop

before and after each use

When should you wash your hands?

before and after lab

Sterilization

destruction of all forms of microbial life

where in the environment are bacteria and fungi found?

everywhere

developing countries

in which parts of the world are liver fluke infections common?

um

micrometers

what information do you include on the petri dish

name date class section and description of specimen, table number

Helminths

parasitic worms - echinoccocus (dog tape worm) - clonorchis (chinese liver fluke) - trichinella ( roundworm)

saccharomyces reproduce asexually by budding. What is a bud?

parent's cell forms a protuberance on its outer surface. as the bud elongates the parent cells nucleus divides and one nucleus migrates into the bud. cell wall material is then laid down between the bud and parent cell, and then the bud eventually breaks away

What is a local infection?

pathogens limited to a small area of the body

how should a test tube be picked up and held in your hand

picked up by the bottom tube portion and held in your non-dominant hand

Filamentous fungi: Vegetative hyphae

present and grows entire life of organism; functions to absorb food/nutrients from surrounding environment)

What does "ubiquity" mean?

present everywhere

what is meant by aseptic techniques

procedures to prevent contamination

what is the name for the infection caused by aspergillus?

pulmonary aspergillus

ocular lens (eyepiece)

remagnifies the image formed by the objective lens

What is the proper disposal procedure for contaminated broken glass?

spray with microban, then place in biohazard bag by picking it up with forceps or with a dustpan to be autoclaved

part of the microscope that moves when you adjust the course Focus knob

stage

trichomonas

structure: unicellular movement: motile disease: STD- trichomonasis= transmitted by sexual contact location: vagina movement: flagella (have 2)

plasmodium

structure: unicellular movement: motile disease: causes malaria-transmitted by mosquitos. -infects RBC and WBC

Saccharomyces ( Brewer's Yeast )

structure: unicellular, non-filamentous. function: makes beer and bread. location: frequently found as a white powdery coating on fruits and leaves. reproduction: asexual by budding. human pathogen: Candida albicans- attaches to human epithelial cells as a yeast but usually requires pseudohyphae to invade deeper tissues. (causes thrush)

how should a test tube be carried from your lab bench to the lab cart after use

test tube rack

Why sterilize media and instruments?

to Destroy all life forms of microbial life

how do arthroconidia differ from conidia? how will you identify them?

conidia are not enclosed in a sac, can spread easily. arthroconidia are in sacs

fine focus knob

used to make fine adjustments to the stage

stage adjustment knobs

used to move the slide on a mechanical stage in vertical and horizontal directions

RBC and WBC

which 2 types of human cells are infected by plasmodium?

where are yeast normally found in nature?

white powdery coating on fruits and leaves

how does a tapeworm feed?

The tapeworm feeds off the food that the host is digesting. It uses this nutrition to grow

list 2 safety precautions that should be taken in the lab regarding clothing and appearance

long hair should be tied up or pulled back. always wear closed toed shoes

list the steps in order that you would have to take to obtain a sample of bacterial culture from a test tube

1. hold test tube and non-dominant hand and remove the cap with the pinky of the dominant hand. 2.flame sterilize the lip of the test tube. 3. hold test tube at a 45 degree angle and insert the loop at an angle. 4. flame sterilize the test tube again then cap it and place in test tube rack. 5. transfer bacterial culture from loop into a petri dish or a test tube

how would you now prepare your microscope for storage and put it away

1. move objective to an empty slot. 2. lower stage. 3. remove slide from the stage clips and place on slide rack. 4. turn off microscope. 5. wipe down microscope with lens papers. 6. disconnect cord and place in drawer. 7. rotate the oculars to face the arm of the microscope. 8. pick up microscope by arm and base and place it in the cabinet with the arm facing the door of the cabinet

what is the total magnification when using the 10x objective?

100x

if a specimen viewed with the 40x objective has a length that is about 1/2 of the diameter of the field of view, what is the approximate length of specimen

460/2= 230um

coccus

A spherical bacterium. Round

Filamentous fungi:aerial hyphae

Aerial hyphae (present only when organism is reproducing; functions to lift and disperse spores)

What is an opportunistic pathogen?

An infectious microorganism that is normally a commensal or does not harm its host but can cause disease when the host's resistance is low

give the name of a yeast that is a human pathogen

Candida albicans

which trypanosome disease is most relevant to the US?

Chagas' disease, also known as American trypanosomiasis, is a protozoan disease of the cardiovascular system

trichinella ( roundworm)

Found in pork, can be fatal. location: adult form is found in the muscles of the small intestine of the host. Hosts: humans and animals. passed on: by ingesting undercooked pig meat. prevention: cook and freeze pig meat

coccidioides (C. immitis)

Fungi. location: dirt reproduction: asexual human disease: valley fever

Penicillium

Fungi. stained purple

illuminator

Illuminates the specimen for viewing

part of the microscope you are allowed to adjust to control the amount of light passing through the specimen

Iris diaphragm

Basic structures of filamentous fungi

Mostly found underground ◦ Made up of microscopic tubular threads called hyphae (singular: hypha) ◦ Entire network of hyphae called mycelium

coarse focus knob

Moves the stage up and down for focusing

why are trypanosome infections difficult to treat?

Sleeping sickness is notoriously difficult to treat considering the toxicity and complex administration of the drugs currently available for treatment. Furthermore, parasite resistance to existing drugs is always a risk.

Sporangiospores

Spores formed in a sac (sporangium)

How do fungal spores differ from bacterial endospores?

Unlike fungal spores, where one fungus can make many spores, bacterial endospores are a "one cell makes one endospore" affair. Endospores exhibit no signs of life, however when the environment returns to a favorable state for bacterial growth the bacterial endospore will germinate and return to a normal state

Filamentous fungi have both vegetative and aerial hyphae. explain the differences in structure and function between these two types of hyphae.

Vegetative hyphae (present and grows entire life of organism; functions to absorb food/nutrients from surrounding environment. Aerial hyphae (present only when organism is reproducing; functions to lift and disperse spores)

intermediate host

a host that gives food and shelter to immature stages of a parasite

which human disease is caused by trypanosomes?

african sleeping sickness

what is a systemic infection?

an infection throughout the body

definitive host

an organism that harbors the adult, sexually mature form of a parasite

what is the relevance of penicillium to humans?

antibiotic, food, drugs

what is a mature ( gravid ) proglottid? how is it involved in tapeworm reproduction?

are found at the end of the strobila and contain the fully developed uterus full of eggs.

Part of microscope that must be facing the cabinet door when you put your scope away

arm

are sporangiospores sexual or asexual. how are they formed?

asexual, formed within a sporangium of Rhizopus

arthroconidia

barrel shaped... shaped from fragmentation of the hyphae. from coccidioides

Rhizopus

bread mold. disease: Rhizopus- pulmonary infection. function: fermentation, lactic acid

how do humans contract Clonorchis?

by eating raw crayfish

how is this trypanosome species transmitted to humans?

by tsetse fly

where in the U.S does this disease commonly occur?

ca, san juaquin

a single microorganism...

cannot be seen with the naked eye

why cant chinese river fluke be transmitted in the US?

cannot be transmitted because its inter- mediate hosts are not in the United States

plasmodium is an obligate intracellular parasite. what does this mean?

cannot reproduce outside their host cell, meaning that the parasite'sreproduction is entirely reliant on intracellularresources

iris diaphragm

controls the amount of light passing through the specimen. (has numbers on it right below the stage)

both penicillium and aspergillus have conidiophores. How do the 2 conidiophores differ from one another?

different color. aspergillus= green, more fan shaped penicillium= purple/blue, looks like a witches broom

echinoccocus

disease:Cystic echinocccosis transmission:By ingesting food, water or soil contaminated with stool from infected dogs. This might include grass, herbs, greens, or berries gathered from fields. By petting or handling dogs infected with the Echinococcus granulosus tapeworm

Proglottids of echinoccocus

each segment in the strobila of a tapeworm, containing a complete sexually mature reproductive system.

how is rhizopus of relevance to humans?

fermentation, alcohol, lactic acid

part of the microscope you must use when the 40s and the 100 X objectives are in place

fine focus knob

what must be done to you used test tubes and any other glassware before they are left on the back cart

flame sterilized and be free from any Sharpie markings and tape

Condenser

focuses light through the specimen

What is mycosis?

fungal infection

Aspergillus

fungi. location: decaying vegetation, compost piles.

rotating nosepiece

holds the objective lenses

stage

holds the specimen

Fluke eggs are introduced into water by means of feces from an infected host. ... Newly hatched worms, termed cercariae,leave the snail host to live inside fish, the second intermediate host

how do eggs of the fluke leave their host?

How is valley fever contracted?who is more susceptible to it?

inhaling dirt, people over 60, weak immune systems

for plasmodium which organism is the definitive and intermediate host?

intermediate: mosquitos definitive: rbc, wbc

what should never be used to wipe the objectives and other glass surfaces of your microscope?

kimwipes or paper towels

objective lens

lenses that magnify specimen with different powers. 10x, 40x, 100x

why should you hold test tubes at a 45 degree angle when the cap is removed and why you should only crack the lid of a petri dish

less surface area is being exposed if test tube is at a 45 degree angle. to prevent contamination from the air entering the expirememt

how is the petri dish placed in metal sleeve to be incubated and stored

lid down and base and labeling on top

where do you label the Petri dish

on the bottom portion

visible growth derived from a single, original microorganism ◦One colony contains billions of cells ◦All cells within a colony are genetically identical

single colony

sporangiophore

specialized hyphae where sporangia are found

protozoa

trypanosoma, plasmodium trichomonas

on off switch

turns the microscope on and off

what human disease is caused by coccidioides?

valley fever