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Short tubes extending outwards from cell
membrane
◦ Like short hairs covering single cells
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Made of “microtubules” or “filaments”
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Like small, hollow straws or thin fibers
Can produce great amounts of force
Require the use of energy to move
80 – 100 nm (nm = billionth of a meter)
 i.e., very small compared to other organelles
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Present in all types eukaryotic cells
◦ Most cells don’t have cilia
◦ Can be present in some animals, plants fungi; more
common in animals
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In general, use cilia to move cell or move
objects along side the cell
Demo: hold up your arms!
Cilia are useful for a variety of tasks
◦ Help single-celled organisms move through water
or other liquids
◦ Help some aquatic organisms filter feed
 move water/food into mouths, into feeding cells, etc.
◦ Moving mucus up respiratory tract in vertebrates
◦ Move water along gills in many aquatic organisms
◦ Communication between cells, possibly
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Cilia can be like the legs of a millipede
◦ All work together to help the insect move
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Or, cilia can be like moveable arm hairs
◦ Could control movement of air, fluids next to skin
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Or, cilia can be like simple antennae
◦ Useful for basic communication?
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Without cilia:
Many single-celled organisms couldn’t move!
You’d drown in your own mucus!
 (cilia move mucus out of your lungs)
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Aquatic organisms’ gills wouldn’t work!
Filter-feeders might starve!
Cells couldn’t communicate!
What could be worse than immovable,
drowning-in-mucus, silent cells that can’t
breathe? Keep the cilia!
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Primary Ciliary Dyskinesia (PCD)
◦ Uncommon disease in which cilia lining trachea and
lungs malfunction
◦ Can cause
 Chronic, recurring infections in lungs, sinuses, ears
 Infertility (cilia-like flagella in sperm don’t work)
 Swelling in brain
 Organ displacement
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List main points here – summarize
Then take questions
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Cover ALL requirements in 3-5 min
◦ Less than 3 min, probably incomplete
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More than one slide per requirement - ok
Bullets with BRIEF INFO!
OK to use color, pictures, backgrounds, fonts
to enhance slides
◦ Don’t overdo it.
◦ Keep format consistent
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May use notes during your presentation
Practice eye contact, voice, difficult words
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It is very, very important that, while you have
plenty of information in your slides, your writing is
not so lengthy and wordy (containing run-on
sentences, for example), that students are so busy
reading it they forget to listen to you and miss
everything you’re saying so your slide becomes not
helpful and distracting. Oh, and please don’t read
from the screen word for word.
Instead, try brief bullets
◦ Containing information that you explain
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Make sure it’s easy to read!
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Make text at least 24 font
 Animations
are ok, but please
don’t have too many or a lot of
different types
Keep
font size
similar
Thanks!