Category: Curriculum Map
Annelid
Annelids
Segmented Worms
All Materials © Cmassengale
Phylum Annelida
Characteristics
- Includes duster worms, earthworms, & leeches
- Abundant in all habitats
- Have a true coelom fully lined with mesoderm
- Body divided into external segments called metameres (metamerism)
- Metameres correspond to internal segments
- Have a one-way digestive system with a mouth & anus
- Well developed brain & sensory organs
- Fluid-filled coelom provides hydrostatic skeleton
- Most have external bristles or setae that aid movement
- Setae may be modified into flashy appendages called parapodia
PARAPODIA
- Includes 3 classes based on number of setae & presence or absence of parapodia
- Classes of segmented worms — Oligochaeta, Polychaeta, & Hirudenia
Class Oligochaeta
Characteristics
- Have no parapodia & few setae
- Includes earthworms
EARTHWORM
- Bodies may have over 100 metameres
- Internal partitions called septa
- Distinct anterior & posterior ends
- Cephalization (head with sense organs) shows specialization for burrowing
- Have both circular & longitudinal muscles for movement
- Have external, saddle-shaped structure called clitellum that forms a cocoon containing eggs & sperm
- Prostomium or lip digs through soil as earthworm feeds on organic matter
- Pharynx is a muscular organ behind the mouth to help suck in food
- Food temporarily stored in crop, ground in gizzard, and digested & absorbed in intestine
- Wastes called castings pass out through anus
- Closed circulatory system with 5 pairs of aortic arches or hearts
- Dorsal blood vessel carries blood posteriorly to cells & ventral blood vessel returns blood anteriorly
- Secrete mucus to keep skin moist so oxygen will dissolve & diffuse into body
- Long tubules called nephridia filter wastes from blood & excrete it through pores
- Simple brain, no eyes, & dorsal and ventral nerve cords
- Sensitive to light, touch, moisture, chemicals, temperature, & vibrations
- Hermaphrodites exchange sperm & cross-fertilize
- Sperm sacs store the worm’s own sperm & seminal receptacles store exchanged sperm
Class Hirudenia
Characteristics
- No setae or parapodia
- Includes leeches
- Have anterior & posterior suckers for attachment
LEECH
- Some suck blood from hosts, while others are scavengers or predators
- Mouth’s of blood-sucking leeches with chitinous teeth & secrete anticoagulant
- Found in freshwater
- Flattened dorso-ventrally
- Hermaphrodites that cross-fertilize
Class Polychaeta
Characteristics
- Marine
- Includes sandworms & clamworms
- Have paddle-like parapodia to move
- Take in oxygen through parapodia
- Some are free-swimming predators with strong jaws to feed on small animals
- Many live commensally with sponges, mollusks, & echinoderms
- Well-developed head with antenna & specialized mouthparts
SANDWORM
Amylase on Starch Lab
| Enzyme Amylase Action on Starch |
INTRODUCTION:
In this experiment you will observe the action of the enzyme amylase on starch. Amylase changes starch into a simpler form: the sugar maltose, which is soluble in water. Amylase is present in our saliva, and begins to act on the starch in our food while still in the mouth.
Exposure to heat or extreme pH (acid or base) will denature proteins. Enzymes, including amylase, are proteins. If denatured, an enzyme can no longer act as a catalyst for the reaction.
Benedict’s solution is a test reagent that reacts positively with simple reducing sugars like maltose, but will not react with starch. A positive test is observed as the formation of a brownish-red cuprous oxide precipitate. A weaker positive test will be yellow to orange.
MATERIALS:
| Cornstarch Distilled water Saliva Vinegar Benedict’s qualitative solution 3 graduated cylinders (10mL) 250-ml beaker Stirring rod 3 test tubes (16 x 125mm) Test tube rack Wax pencil Water Bath |
 |
PRE-LAB:
Add 1g of cornstarch to a beaker containing 100ml of cold distilled water. While stirring frequently, heat the mixture just until it begins to boil. Allow to cool.
PROCEDURE:
1. Fill the 250-mL beaker about 3/4 full of water and place on the hot plate for a boiling water bath. Keep the water JUST AT BOILING.
2. Mark 3 test tubes A, B and C. “Spit” between 1 and 2 mL of saliva into each test tube.
3. Into tube A, add 2 mL of vinegar. Into tubes B and C, add 2 mL of distilled water. Thump the tubes to mix.
4. Place tube B into the boiling water bath for 5 minutes. After the five minutes, remove from the bath, and place back into the test tube rack.
5. Add 5 mL of the starch solution to each tube and thump to mix. Allow the tubes to sit for 10 minutes, occasionally thumping the tubes to mix.
6. Add 5 mL of Benedict’s solution to each tube and thump to mix. Place the tubes in the hot water bath. The reaction takes several minutes to begin.
OBSERVATIONS:
Tube A: Starch + saliva treated with vinegar (acid)
-
- Was the test positive or negative? _______________________
What does this indicate?__________________________________________________
____________________________________________________________________
____________________________________________________________________
Tube B: Starch + saliva and water, treated in a boiling water bath
-
- Was the test positive or negative? _______________________
What does this indicate?__________________________________________________
____________________________________________________________________
____________________________________________________________________
Tube C: Starch + saliva
-
- Was the test positive or negative? _______________________
What does this indicate?__________________________________________________
____________________________________________________________________
____________________________________________________________________
QUESTIONS:
1. What is the function of an enzyme?
2. Where does a substrate attach to an enzyme?
3. If an enzyme is present in a reaction, less ________________ _________________ will be needed to get the reaction started.
4. What is a common suffix found at the end of most biological enzymes?
5. Most enzymes are macromolecules called ________________.
6. Define denaturation of proteins.
7. Name 3 things that can denature or unfold an enzyme.
8. In this lab, what weak acid denatured the protein?
9. What was the purpose of placing one test tube in a hot water bath?
10. What happens to enzymes in your body whenever you run fever?
Antibiotic Resistant Lab
Antibiotic resistance of bacteria
Procedure Using a sterile loop, pick an isolated colony from you bacterial plate. Try to find one that grew well but is all by itself. Move the colony (don’t scoop up the agar) to a new plate. 
Using a moist, sterile, cotton swab, spread the bacteria around on the plate.
The goal is to get an complete, even, coverage of bacterial growth on the plate (called a “lawn”). Remember to open the plate only minimally, using the lid as an “umbrella” to prevent contamination (see image below). Label each plate on the bottom (agar contaning side) and store it for examination during next week’s lab.Each new prepared plate will receive four paper discs containing antibiotics. We will be using several different types of Antibiotics and/or antimicrobials.
(please fill in which antibiotics you used below)
- 1
- 2
- 3
- 4
The antibiotic discs come in a little tube-like dispenser. To remove the discs take a sterile toothpick
and push out a disc into your plate. Use the toothpick to gently press the disc onto the agar. Once you have added the five antibiotic discs to your plates, make sure the plates are labelled and store them in the back of the lab until next week.
If the bacteria are susceptible to the antibiotic a zone of inhibited growth will be evident next week. Measuring the size of this zone is a relative indication of the effect of the antibiotic on the particular bacteria.
Bacteria possess several characteristics that enable them to become resistant to antimicrobial drugs:
- Asexual reproduction
- Short generation times
- High mutation rates
Some Information on Antibiotics
Questions –
1. Name two ways (1. and 2. ) that common human practices towards antimicrobials aids bacteria in becoming resistant.
2. Name two reasons your Physician will perform cultures such as the ones you have done in this lab.
4. How are materials are collected for cultures?
5. Why is neccesary to use sterile technique when obtaining cultures?
