Lab 1 Flashcards
Summarize the steps to use a microscope. (6 steps)
- clean microscope lenses and adjust the light intensity to 7
- secure the slide on the stage and center the specimen
- set the condenser
- focus (coarse) and center at 4x
- focus (fine) and center at 10x
- focus (fine) and center at 40x
What are 3 reasons your image is too dark or too bright after adjusting the iris diaphragm? (even after adjusting the light intensity)
- Slide isn’t correctly placed
- Dirt on the objective or ocular lenses
- Dirt on the microscope slide
What is the formula to find the actual size of an organism when looking at it under a microscope?
actual size = (diameter of field of view/ # of times the organism can fit across the field of view)
What is the actual diameter of field of view when using 4x, 10x, and 40x?
4x = 4.40 mm 10x = 1.75 mm 40x = 0.44 mm
What are the four structural features that all living cells have in common?
- plasma membrane
- cytoplasm
- DNA
- ribosomes
What are chains of prokaryotes called?
filaments
What are aggregates of prokaryotes called?
colonies
Do prokaryotes have a nucleus? What do they have instead? What is it’s function?
No. They have a nucleoid. It contains the DNA.
Do prokaryotes have organelles?
No.
Know the diff between TEM and generalized drawings.
YUP
Which is larger in size? Prokaryotes or eukaryotes?
Eukaryotes
Are eukaryotic organisms unicellular or multicellular?
They can be both.
Do all eukaryotes have a cell wall?
No not all.
Do animals have a cell wall? Do plants have a cell wall?
animals no. plants yes.
what color are central vacuoles under a microscope?
They are colorless.
What color are chloroplasts under a microscope?
Green.
What are cell contents called?
Cytoplasm
What color is a nucleus under a microscope?
Colorless.
What is the nuclear material of prokaryotes?
- no nuclear membrane
- usually one circular chromosome in a region called the nucleoid
What is the nuclear material of eukaryotes (specifically plants and fungi)?
- nuclear membrane present
- linear chromosomes
What is the nuclear material of eukaryotes (specifically animals)?
- nuclear membrane present
- linear chromosomes
What is the cell wall material of prokaryotes?
- polysaccharides
- amino acids
What is the cell wall of eukaryotes (specifically plants and fungi)?
- cellulose in plants
- chitin in fungi
What is the cell wall material of eukaryotes (specifically animals)?
-N.A. (absent)
Are there membrane bound organelles in prokaryotes?
No
Are there membrane bound organelles in eukaryotes (specifically plants and fungi)?
Yes
Are there membrane bound organelles in eukaryotes (specifically animals)?
Yes
What is another name for blue-green algae?
Cyanobacteria
What is the part on the outside of the cell wall of cyanobacteria that encases the filament?
-gelatinous sheath
Organisms differ in their ____ to organic pollution.
tolerance
How do you find relative total pollution index (rTPI)?
multiple the PI by the frequency.
How do you find TPI?
Add all of the rTPI.
What does a value of 4-5 TPI indicate on the pollution index?
High organic pollution.
What does a value of 2-4 TPI indicate on the pollution index?
Probable organic pollution.
What does a value under 2 TPI indicate on the pollution index?
Low organic pollution.
What numbers do frequencies fall between?
0-1
What does the sum of all frequencies have to add up to?
1.
What are the 4 types of microscopy?
- Fluorescence
- Confocal laser scanning
- Transmission electron (TEM)
- Scanning electron (SEM)
Describe fluorescence microscopy.
Fluorescent molecules absorb a particular wavelength of light and emit some of the absorbed light at a different wavelength. Fluorescent dyes can be bought but chlorophyll is a natural example. The images are viewed on a black background.
Describe confocal laser scanning microscopy.
A type of fluorescence microscopy using a laser light source on a very thin plane within a fluorescent specimen. Laser scanned specimens emit fluorescence that is detected in digital form and then the microscopes computer makes a thin image. Used on thick objects. Provides a 3D image.
Describe a TEM.
A beam of electrons is transmitted through a very thin section of the specimen. It has the best resolution of internal organization of cells and their organelles.
Describe a SEM.
A beam of electrons is scanned over the surface of a specimen. creates a 3D image of the surface of the specimen. This can be used to look at intact specimens such as insects.
What does the iris diaphragm do?
It adjusts the resolution.
What does the condenser do?
It focuses the light at the level of the specimen.
What are the two groups of prokaryotes?
- archaea
- bacteria
What are the four groups of eukaryotes?
- plants
- animals
- fungi
- protist
What is gelatinous outer covering found on some bacteria cells called?
glycocalyx
What is the function of glycocalyx?
It traps water and protects the bacteria from desiccating.
