Curriculum Map 57 - BIOLOGY JUNCTION

Biology Study Guides Summary of Links

Biology Study Guides
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Safety & Equipment		Chromosomes		Flat & Round Worms Unsegmented Worm Review
	Study of Life Intro to Biology Review Chapter 1 Introduction		Taxonomy Taxonomy Review Cladogram Practice		Mollusks Mollusk Review
Chemistry Chemistry Review		Evolution Evolution Review		Annelids Annelid Review
	Biochemistry Biochemistry Review	Viruses Virus Review		Arthropods Arthropod Review
Cells Cells – Units of Life Cells & Their Functions Cell Review Cell Study Guide		Bacteria & Viruses Bacteria & VirusesBacteria Review		Insects Insect Review
Homeostasis & Transport Handout – TRANSPORT Cell Membrane Review Transport Study Guide		Fungi Fungi Review		Echinoderms Echinoderm Review
	Photosynthesis Photosynthesis Review		Protists Protist Review		Fish Fish Review
	Photosynthesis & Respiration Photosynthesis & Cell Respiration		Mosses & Ferns		Amphibians Amphibian Review
	Cellular Respiration Cell Respiration Review		Seed Plants		Reptiles Reptile Review
	Nucleic Acids Nucleic Acid Review		Plant Structure & Function		Birds Birds Review
	Cell Growth & Division Cell Cycle & Mitosis Cell Reproduction Review		Introduction to Animals Intro to Animals Review Invertebrate Table		Mammals Mammal Review
	Genetics Genetics flashcards Genetics Review		Sponges & Cnidarians Review Worksheet	Ecology Ecology Review Cycles Worksheet Biogeochemical worksheet
	1st Semester 2003 2nd Semester 2003		1st Semester 2004 2nd Semester 2004		1st Semester 2006 1st Semester 2012

Biology I

PreAP Biology

Strawberry DNA

Strawberry DNA Extraction

Adapted from a lab by C. Sheldon

Introduction:

DNA is found in cells from Animals and Plants. DNA is a double stranded macromolecule composed of nucleotide bases pairing Adenine with Thymine and Guanine with Cytosine. DNA can be extracted from cells by a simple technique with household chemicals, enabling students to see strands of DNA with the naked eye.

Purpose:

To extract DNA from the fruit of a strawberry plant

Safety Precautions:

Do not eat or drink in the laboratory.
Wear Apron & Safety Goggles.

Materials / Equipment (per student group):

1. heavy duty zip-lock baggie

2. 1 strawberry (fresh or frozen and thawed)

3. cheesecloth

4. funnel

5. 100 ml beaker

6. test tube

7. wooden coffee stirrer

8. DNA Extraction Buffer (One liter: mix 100 ml of shampoo (without conditioner), 15 g NaCl, 900 ml water OR 50 ml liquid dishwashing detergent, 15 g NaCl and 950 ml water)

9. Ice-cold 95% ethanol or 95% isopropyl alcohol

Procedure:

1. Place one strawberry in a zip lock baggie and carefully press out all of the air and seal the bag.

2. Smash the strawberry with your fist for 2 minutes.

3. Add 10 ml extraction buffer to the bag and carefully press out all of the air and seal the bag.

4. Mush again for one minute.

5. Filter through cheesecloth in a funnel into beaker. Support the test tube in a test tube rack.

6. Discard the extra mashed strawberry.

7. Pour filtrate into test tube so that it is 1/8 full.

8. Slowly pour the ice-cold alcohol into the tube until the tube is half full and forms a layer over the top of the strawberry extract.

9. At the interface, you will see the DNA precipitate out of solution and float to the top. You may spool the DNA on your glass rod or pipette tip.

10. Spool the DNA by dipping a pipette tip or glass rod into the tube right where the extract layer & alcohol are in contact with each other. With your tube at eye level, twirl the rod & watch as DNA strands collect.

Prelab:

Take a look at the sketch of the plant cell below. The chromosomes (which are made of DNA) are in the nucleus. This is the only place where DNA is located.

Now match the procedure with what it is doing to help isolate the DNA from the other materials in the cell.

_____1. Break open the cell	A. Squish the fruit to a slush
_____2. Dissolve cell membranes	B. Filter your extract through cheesecloth
_____3. Precipitate the DNA (clump the DNA together	C. Mix in a detergent solution
_____4. Separate organelles, broken cell wall, and membranes from proteins, carbohydrates, and DNA	D. Layer cold alcohol over the extract

DNA Extraction Table

	AMOUNT ADDED OR OBTAINED	INITIAL COLOR	PURPOSE
BUFFER (soap-salt mixture)
STRAWBERRY
COLD ALCOHOL
DNA

SKETCH OF TEST TUBE WITH CONTENTS

Questions:

1. Where can DNA be found in the cell?

2. Discuss the action of the soap (detergent) on the cell. What is the purpose of the soap in this activity?

3. What was the purpose of the Sodium Chloride? Include a discussion of polarity and charged particles.

4. Why was the cold ethanol added to the soap and salt mixture?

5. Describe the appearance of your final product?

6. Draw a diagram of DNA containing 5 sets of nucleotide bases labeling the hydrogen bonds between the bases.

Sponge & Cnidarian Study Guide

Study guide for Sponge, Cnidarians, & Ctenophores

·         Know relatives of the jellyfish
·         How are sponges different from other animals
·         Know characteristics of all invertebrates
·         Know characteristics of sponges
·         What is the function of collar cells in sponges
·         What are spicules
·         Know characteristics of adult sponges
·         Be able to explain skeletal support of sponges
·         How do sponges obtain their food
·         What helps draw water into a sponge
·         What is the function of amebocytes in sponges
·         How does excess water leave a sponge
·         What is the purpose of gemmules in sponges
·         What is a hermaphrodite
·         How can sponges reproduce
·         Know animals that capture prey by using nematocysts
·         What are the 2 distinct life stages of cnidarians
·         Describe nematocysts
·         What organisms have tentacles with stinging cells
·         Know examples of cnidarians
·         Describe the life of a planula larva
·         Know the life stage that is dominant in sea anemones
·         What organisms would be anthozoans
·         Know the dominant life stage of jellyfish
·         Know the main characteristics of ctenophores

BACK

Squid Dissection

Squid Dissection

Objectives:

As a result of this lesson, students will be able to:

Locate and identify major external and internal features and organs of a squid.
Understand and use basic dissection techniques and terms.
Critically examine the functions of several squid features and organs.

Teaching Notes: This lab is a very thorough dissection of a squid and can be adapted to different grade levels. Teachers should try the lessons, considering which parts are most appropriate for their students and curriculum. The descriptions use complex dissection terminology. Be certain students understand the vocabulary of dissection prior to beginning the lab.

These lessons were tested with middle school students ages 11 to 13. They followed procedures and understood concepts well. The skills necessary to do all steps in the dissection are within the normal ability range of middle school students.

Materials:

squid*
scissors
toothpicks (for probes and pointers)
drawing paper
forceps
hand lens (5x recommended)
small cups (ketchup cups work well)
dissecting pan (or lunch trays)
paper towels
diagram of squid
wash bottle
microscope (optional)
dissecting scopes (optional)
slides (optional)
slide covers (optional)

*Look for squid at the local supermarket in the seafood and frozen foods sections. You may have to order it in advance. For areas that have them, you can also go to the local fish market or oriental food stores, or you can deal directly with fishermen.

Teaching Notes: Squid specimens tend to deteriorate rapidly. Keep all squid frozen until the morning before dissection. Thaw the squid in the refrigerator. If the entire dissection cannot be completed in one day, do the external activities while the specimens are still partly frozen, and the internal activities the next day after squid are thawed.

Squid may have tentacles or arms missing. Individual squid vary internally, and their relative maturity determines which organs are formed well enough to be seen clearly, and which have lost (or have yet to gain) their shape and coloration. Please advise students that they may not see everything shown in the enclosed diagram. Tissue shrinks and organs become misshapen quickly. To help maintain the freshness of the specimen, cover it with a wet paper towel as you work so it does not dry out so quickly.

Finally, this lesson is a tactile experience. You may want to explore this aspect through sensory activities, written descriptions, poetry, and/or artwork. Encourage students to experience the many textures found inside and outside the squid’s body. Moving fingertips along the suckers is suggested as well – the suckers do not scrape or hurt if you are gentle with them.

Procedure

Orientation:

Place the squid with the dorsal (back) side up in the dissecting pan. This means put the side with the funnel down and the fin side up. Make sure the tentacles and arms are towards you. Locate the head, eyes, beaks (mouth), arms (8), two longer feeding tentacles, fins, mantle, and skin. Use the hand lens to examine the suckers on the tentacles and arms as well as the spots on the skin, which are chromatophores.

What are the differences between arm and tentacle suckers? Where are the suckers located on the feeding tentacles as compared to the location of the suckers on the arms?

How do you account for the different locations of the suckers on the tentacles and the arms? What are chromatophores?

The Mouth and Beaks: Locate the dark beaks in the center of the mouth.

Open and close the beaks, noting how the ventral beak overlaps the dorsal beak. How is this different from a parrot’s beak? Before you pull out the beaks, imagine what they will look like on the inside. With tweezers, remove the beaks and place beaks together with dark pointed parts opposite one another. Manipulate them (open and close) as if the squid were eating. What makes them work in this way?

In order to remove the radula (a ribbon with rows of teeth on a tongue-like muscle) from inside the mouth, make small incisions in the edge of the mouth. With tweezers, locate the small, folded, plastic-like radula between beaks and remove it. It is usually very small, yellow or white in color. What is the radula’s function? Store the radula and the beaks in water in a small cup if you are going to do a microscopic examination.
Funnel:
Turn the body over, ventral side up, and locate the funnel (a deflated fleshy tube located at the base of the head). A squid swims by squirting water from the mantle through the funnel. The direction it swims depends on which way the funnel is aimed. Move the funnel and note its flexibility.
External Anatomy:
Orient the squid so that the tentacles are away from you, at the top of the dissection tray. Spread out the arms, tentacles, and fins. Draw and label the external parts of the squid: arms, tentacles (have suckers only at the tips), head, eyes, fins, mantle, funnel, tail, suckers, beaks (where each would be found on an intact squid) and mouth. If something cannot be seen, draw an arrow to show where it should be.

If you have time, slice open an eyeball and locate the lens, pupil, retina, and iris (colored part of the eye). Look for the creamy white brain between the eyeballs. For assistance in identifying these parts, refer to the illustration below.
Opening the Mantle:
Keep the squid on its back (the side opposite the funnel). Using forceps, lift up the opening to the mantle behind the funnel (near the head) and separate the mantle from the internal organs. Close the forceps firmly so as to “pinch” the mantle flesh to keep it taut, cut along the ventral midline of the mantle, from its opening all the way to the tail. Be careful to keep the scissors lifted away from the internal organs so they are not damaged.
Locating and Removing Reproductive Organs:
Locate the gonad (reproductive organ) in the posterior end (refer to diagram for shape and location).

Upon opening female specimens, the large, firm, white nidamental glands are seen first. Males do not have nidamental glands. The glands lay on top of the other internal organs. These glands create the gelatinous matrix that envelops the eggs. In order to proceed further, carefully remove these glands. In females the eggs are jelly-like in a conical sac at the posterior end of the mantle. The male genital duct is a white, fluid-filled sac in the posterior end of the mantle. The sperm are stored in thin tubes in an elongated sac behind and along one gill.
Gills:
Find the gills. These are the long, feather-shaped organs that are attached to the sides of the mantle and extend along the anterior half of the mantle. Identify the gill hearts, one on the posterior end of each gill (these are small, flat and white). Questions: Why are they white and our hearts are red or purple? The squid has a third heart (the systemic heart) that pumps blood to the rest of the body.

Challenge: Why does it have separate hearts for the gills alone?
Digestive Tract:
The long, silvery dark tube on the bottom of the liver (but appearing to be on top of the liver because of the squid’s inverted position) is the ink sac. Be careful not to break it open. Locate the stomach and caecum. These lie together as one white, silky-looking tube, like a deflated bladder and a coiled sack. The bunched up organs that look like human intestines are digestive ducts for the squid. If you are curious about the liver, wait to cut it open until the end of the dissection. It contains a lot of brown, oily liquid which may obscure other organs. If possible, open the stomach and examine its contents. Many squid will have bits of partially digested crustaceans (pink and white pieces), or tiny fish scales and bones.
Removing the Ink Sac:
Find and carefully remove the silvery-black ink sac that lies connected to the intestine. To do this, pinch the opening of the sac (near the back of the funnel) with forceps while gently pulling up and cutting the connective membrane along its length. After cutting about 1/3 to 1/2 of it, hold the sac with your fingers and pull the sac off the liver. Be careful not to puncture it. Squid ink stains clothing and skin. Place the sac in a small cup for later use with the gladius (pen).
Removing the Gladius (Pen):
The gladius is a long, clear feather-shaped structure used to support the mantle and for organ attachment. It and the cranium, or brain case, make up the “skeleton” of the squid. It feels like plastic and is made of tissue similar to a shrimp shell. There are two ways to remove it: from the tail or from inside the cut-open mantle. To remove it from inside the open mantle, grasp the head and organs firmly, and rotate them to the side with your left hand while holding on to one side of the mantle with your right hand and pulling away gently. Pulling the gladius out is like removing a splinter from your skin. You may need to cut away connective tissues that hold the gladius in place.

The gladius is revealed, lying along the dorsal midline of the mantle.

Grab the forward end of the gladius and pull it carefully from its slot in the mantle. It may be helpful to have one person hold down the lower mantle while the other removes the gladius. To remove from the tail end, rotate the organs to one side, cutting connective tissues. Make sure the mantle is slit along the internal dorsal midline all the way to the tip of the tail. Pry out the tail end of the gladius and pull straight back, away from the body.
Writing with the Gladius (Pen) and Squid Ink:
Cut one end of the ink sac open and press it against the bottom of the cup with forceps or toothpick. You can also hold one end and push the ink out with your finger, as you would toothpaste from a tube. This will release the ink. Dip the pointed tip (the anterior end) of the gladius into the ink, filling the tip with the dark fluid. Then, using only the ink-filled tip of the gladius, write your name on your squid illustration or paper. If there is enough ink, create and write the name of your dissected squid under its picture. If the ink seems dry and pasty, add one drop of water at a time to create fluid ink. Though this is an unusual way to write, squid ink was actually used to write and draw in ancient times, and it is used today in some cultures. Unfortunately, it tends to fade over time (except from your clothes!).
Internal Anatomy:
Draw, label, and identify the function of the following internal parts of the squid:
- stomach
- caecum
- hearts (systemic and gill)
- gills
- reproductive organs
- ink sac
- liver (digestive gland)
- gladius
- brain
- eyeball
Microscope Slide Option:

The following parts of the squid make excellent specimens for microscopic study:
- eggs from the ovaries
- suckers
- nidamental glands
- tips of arms and tentacles
- spermatophores
- connective membranes (thinly-sliced: mantle, fin, arm muscle)
- radula
- stomach contents
- liver fluids
- skin and chromatophores
- portions of the eye
- beak
Teaching Note: Most of these are useful only for a dissecting microscope.

Questions for further Investigation:
- Identify the differences between the tentacles and the arms. Why are they different?
- How are squid mouths and beaks like your jaw and teeth? How are they different?
- How does the squid use the funnel and mantle for locomotion?
- How does the squid obtain oxygen from the water?
- How do squid reproduce?
- Why are the chromatophores important to the squid?
- What are the relatives of the squid?
- What are the characteristics of cephalopods and of mollusks?
- Why is it difficult to identify stomach contents?
- What is the function of the fins?
- What organ systems are the same or different from vertebrates?
When finished, clean your area completely. Return all equipment and wash your hands. The squid odor will remain for a little while. Lemon juice will alleviate the odor if you find it offensive. To dispose of your specimen, wrap it in plastic or a zip-lock bag and throw it away. You may want to feed it to your cat, cut it up for fish bait, or even serve it as tonight’s calamari. Bon Appetite! Visit Clyde’s Kitchen on this website for tasty squid recipes!

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Starfish Dissection

Starfish Dissection

Introduction:

Echinoderms are radially symmetrical animals that are only found in the sea (there are none on land or in fresh water). Echinoderms mean “spiny skin” in Greek. Many, but not all, echinoderms have spiny skin. There are over 6,000 species. Echinoderms usually have five appendages (arms or rays), but there are some exceptions.

Radial symmetry means that the body is a hub, like a bicycle wheel, and tentacles are spokes coming out of it (think of a starfish). As larvae, echinoderms are bilaterally symmetrical. As they mature, they become radially symmetrical.

Most adult echinoderms live on the bottom of the ocean floor. Many echinoderms have suckers on the ends of their feet that are used to capture and hold prey, and to hold onto rocks in a swift current.

Sea Stars
Sea stars (group name Stelleroidea) are sometimes called starfish, though they are not real fish (they lack both vertebrae and fins). There are two sub-types of sea stars:

Asteroideas are the true sea stars and sun stars.
Ophiuroideas are brittle stars and basket stars.

The differences between the two sub-types lies in how the arms connect to the central disk. Ophiuroids have arms that do not connect with each other. There is a distinct boundary between arm and central disk. Asteroids have arms that are connected to each other. Also, it is harder to tell with asteroids where the central disk ends and the arms begin.

The sea star’s top surface (or skin) looks spiny if you examine it. If you look very closely you will notice that there are different types of growths on the surface. Some bumps are used to absorb oxygen, they are called dermal branchiae. Pedicellaria are pincher-like organs used to clean the surface of the skin. Barnacle larvae could land on a sea star and start growing if it were not for these organs.

How Do Sea Stars Move?
Each sea star had hundreds of tiny feet on the bottom of each ray. These are tube feet, or podia. These tiny feet can be filled with sea water. The vascular system of the sea star is also filled with sea water. By moving water from the vascular system into the tiny feet, the sea star can make a foot move by expanding it. This is how sea stars move around. Muscles within the feet are used to retract them.

Each ray of a sea star has a light sensitive organ called an eyespot. Though it can not see nearly as well as we do, sea stars can detect light and its general direction. They have some idea of where they are going.

Can Sea Stars Grow New Arms?
Given enough time, sea stars can grow back arms that have been damaged or removed. For a few species, the severed arm can grow back into a complete sea star! For most sea stars, however, a severed limb dies.

What Do Sea Stars Eat?
Sea stars eat many things. A sea star’s diet can include: barnacles, snails, sea urchins, clams, and mussels. A few species, such as the spiny star of the North Atlantic, eat other sea stars! Many sea stars eat mussels and clams in an interesting way. They surround the shell and use the suckers on their feet to pull the two shells (or valves) apart. The sea star has enough force in its arms to actually bend the shell! This creates an opening between the two shells that is only .01 inches wide. Using this tiny gap, the sea star puts its stomach into the clam’s shell and eats its insides. When it is done, nothing is left but an empty shell.

Materials:

Preserved starfish, dissecting pan, scissors, scalpel, forceps, T-pins, pencil, lab apron, safety glasses

Procedure: