ib bio intro to cells/lab 4 quiz (unit 2)

anton von leeuwenhoek

developed 1st microscope, saw “animalcules”

robert hooke

while looking at cork, coined the term “cell”

robert brown

noted that plant cell nuclei were important to the viability of cells

jakob schleiden

noted that all plants are made up of cells

theodor schwann

noted all animal tissues are made up of cells

rudolf virchow

added info about cell division

what are the 3 points of cell theory?

1. all living things are made up of cells 

2. cells are most basic unit of life

3. cells come from pre-existing cells

what are the basic functions of life?

requires energy, respond to environment, homeostasis

excrete

getting rid of nitrogenous waste

most prokaryotic cells are _________

1^-10 mm

most eukaryotic cells are __________

10^-100 nm

which eukaryotic cells have an atypical structure compared to others?

skeletal muscle, fungi, giant algea, red blood cells

whats the limit a light microscope can resolve to?

1 nm

under a light microscope, how can we see colorless chemicals?

we can add stains that bind to them

if the light source is powerful enough what will some chemicals do?

some chemicals will fluoresce if the light source is powerful enough

cross section TEM

used for transmission of electron microscopy

how do you hold a microscope?

one hand grasping the arm, the other under the base

what happens during cross-sectional TEM?

an electron beam (short wavelengths) is magnified by elector magnets and the sample is preserved

surface SEM

used for scanning and creates a highly focused electron beam

what happens during surface SEM?

an electron beam bounces off a metal plated specimen to the detector

what is the pro to electron microscopes?

better resolution and magnification

what are the cons to electron microscopes?

only black and white images, practicality, preparation always kills the cells

the bigger the cell gets, the __________

smaller the surface area

what type of relationship do cell size and surface area have?

they have an inverse relationship

what happens as the volume increases?

the cell requires more nutrients and produces more heat and waste

which increases faster in a cell: surface area or volume?

volume

why is it called a ‘compound microscope’?

the image is produced using the ocular lens times the objective lens

what part of the microscope moves when you turn the coarse adjustment?

the body tube

what motion does the fine adjustment produce?

it adjusts the stage

fine adjustment

making small, precise movements to sharpen the focus of a specimen

coarse adjustment

adjusts the height of the stage to try and focus onto the specimen

diaphragm

adjusts amount of light shining through

why is fine adjustment used for high power?

distance between object and stage is small, and the coarse adjustment does not focus clear enough

What power is better for scanning

Low objective because you are able to get a better field of view and focus on the image better

What is an advantage of an electron microscope over a light microscope?.

An electon microscope has a higner resiution than a light micrascope

What is an advantage of a light microscope over an electron microscope?

The light microscope does not klicells while an electron microscope does

fine adjustment

Precise focus adjustments on the specimen being observed

Revolving nosepiece

Switches objectives from high to low power