Lab #2: Mussels Flashcards
Scientific name, phylum, and class for Blue Mussels
Mytilus Edulis
Phylum = Mollusca
Class = Bivalvia
What are bivalves?
= organisms possessing two valves or shells
What and how (the major process) do mussels feed?
–> They eat plankton
–> SUSPENSION FEEDING
Pathway of plankton ingestion and excretion by mussels
- Inhalant siphon
- Ctenidia
- Labial Palps = SORTING
4A. Components sorted as NON-food released as pseudofeces through the INHALANT SIPHON
4B. Components sorted as food = go to mouth
5. GI tract
6. Anus
7. Exhalant siphon
What are ctenidia?
Ctenidia are comb-like or feather-like gills
–> Respiratory organs that also play a role in filtering ingested food
What is the organization of ctenidia?
The ctenidia are divided into two demibranches that are connected by ciliated filaments
What is the direction of flow in the ctenidia?
Ingested food moves from the posterior (siphon end) to anterior (mouth end) end through the demibranches and filaments
–> Some particles may move from dorsal to ventral (top to bottom) through the filaments to the opposite demibranch and then continue in the anterior to posterior direction
THEN the food that is sorted in the labial palps as NOT FOOD (pseudofeces) gets sent ANTERIOR to POSTERIOR to be released at the inhalant siphon
A = Inhalant Siphon
B = Ctenidia
C = Bysuss
D = Foot
E = Inner Labial Palp
F = Anterior Adductor Muscle
G = Mouth
H = Outer Labial Palp
I = Posterior Adductor Muscle
J = Anus
K = Exhalant Siphon
Denote the anterior, posterior, dorsal, and ventral ends of the mussel
Note: To remember dorsal vs ventral, think of a DORSAL FIN = on the back of whales, therefore dorsal refers to the spinal area!
What are the byssal threads for in mussels?
To aid in attaching to rocks
What is a standard curve?
A graph that depicts the relationship between the concentration of a known substance and its measured response
–> The slope of this graph can be then used to determine the concentration of an unknown sample using its measured response
What was the standard curve for the mussel filter feeding experiment?
X-Axis = Concentration (of known samples)
Y-Axis = Absorbance of the known conc. sample
How to create a standard curve:
- Plot the points for the different known conc. samples and their observed response (Ex: absorbance)
- Add a line of best fit to the points (make sure R2 is high)
- Use the line equation from the standard curve to determine unknown conc. from measured response
How did we use standard curve to determine unknown conc. of algae in solution? Show calculations
The standard curve line equation (y=mx+b) could be used to determine the unknown conc.
B (y-int) we set to ZERO
Y = absorbance and X = conc.
M = slope of line of best fit
–> We want to plug in Y from the unknown conc sample, using the M value from the standard curve and SOLVE FOR X
As time went on, did the absorbance of the algae solution increase or decrease?
What did this signify?
The absorbance of the solution DECREASED over time as the solution was becoming more cleared of particles = less substances in the solution to absorb the light
–> Signified that the mussels were filter feeding successfully! (water was becoming motr coear)
What is a serial dilution?
A serial dilution is a step-wise series of dilutions, where the dilution factor stays the same for each step
–> Ex: Dilute a solution 4x and then dilute that diluted solution 4x to get a 16x dilution and then dilute that dilution 4x to get a 64x dilution…
What pieces of info are needed in order to conduct a serial dilution?
- Concentration of stock solution (non-diluted/reference soln.)
- Dilution factor
- Required FINAL VOLUME
What is the transfer volume in serial dilutions?
How much of the stock solution must be added to the diluent to create the wanted dilution
AND then how much of each diluted solution needs to be added to diluent in order to generate subsequent dilutions
the amount of sample you physically transfer to create the next dilution step
What is the diluent in serial dilutions?
The substance that a given concentrated sample is being diluted into
How do you calculate transfer volume for serial dilution?
(Desired Final Vol. / Dilution Factor) = Transfer vol.
How to determine the amount of diluent to add to each tube in a serial dilution?
Diluent vol. = (Desired final vol.) - (Transfer vol.)
How can you determine concentration of a given dilution in a serial dilution?
Divide the initial concentration (of the undiluted sample) by the dilution factor for the given dilution you want to calculate the concentration for
Serial dilutions are _________
Exponential
–> Each subsequent dilution is just the previous dilution times the dilution factor
Ex:
1st dilution = 4x
2nd dilution = 4 x 4 = 16x
3rd dilution = 4 x 4 x 4 = 64x
4th dilution = 4 x 4 x 4 x 4 = 256x
ETC..
How to balance centrifuge with trio of tubes vs a pair of tubes
Trio of tubes = FORM TRIANGLE (7 spaces between each tube)
Pair of tubes = PLACE EQUIDISTANT (11 spaces between the tubes)
