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Bios 1130
Bacteria
Lab 1
Introduction
Prokaryotes, or bacteria, play a significant and vital role in the processes of life on earth.
These include contributing to the functioning of organisms and ecosystems. Many bacteria
are beneficial to animals and aid in the digestion of cellulose for herbivores and produce
nutrient products for humans in the form of vitamin K and B12. Plants form symbiotic
relationships with certain nitrogen fixing bacteria, where nitrogen gas is captured and
converted into ammonium product which the plant can use. In addition bacteria are
massive recyclers, returning nutrients back into the ecosystem with decomposition of
almost any type of material, organic or inorganic. However bacteria can also be very
harmful to organisms. Some common diseases caused by bacteria are the bubonic plague,
Lyme disease, tooth decay, as well as certain types of infections common to humans and
animals.
Bacteria are very small single-celled organisms, usually ranging from 0.2 – 10 micrometers
in diameter. They have a simple internal structure and have a DNA region with ribosomes
and enzymes. They also have a cell wall composed of a polymer called peptidoglycan. The
common internal structure and lack of species specific anatomy and development makes it
difficult to classify bacteria. Scientists have turned to certain characteristics of bacteria to
differentiate between species. These characteristics include cell shape, habitats, nutrient
needs, mobility, colonization type and staining types. Scientists have also realized that
bacteria species are highly specific for a certain range of living conditions and nutrient
resources.
Objectives
In lab today you will be:
1. Exploring bacteria using some of the techniques used in microbiology to determine
if bacteria are gram negative (-) or gram positive (+).
2. Determining certain shapes of bacteria using prepared slides.
3. Investigating where bacteria live and form a hypothesis and execute data collection.
Gram Staining
Certain bacteria are able to absorb a dye called crystal violet in their cell walls. Other
bacteria will not absorb the dye and this gives scientists a tool to help determine the
possible species of bacteria they are investigating. Bacteria that are able to absorb this dye
are called Gram positive (+) and those that cannot are called Gram negative (-). Certain
antibiotics will work with Gram positive and some only with Gram negative.
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You will be testing for Gram negative and Gram positive bacteria, using crystal violet dye on
a total of four given bacterium. The bacteria tested will be Bacillus cereus (B), Micrococcus
luteus (M), Escherichia coli (E) and Serratia marcescens (S).
Procedure
1. Wash two microscope slides with soap and water and pat dry with a lens wipe.
Using a marker, label one slide with B on the left and E on the right. Mark the second
slide with M on the left and S on the right. These initials will help keep track of
which bacterium you are staining.
2. Place one loop of distilled water on each slide, keeping the drops separate. Flame a
bacterial loop and let it cool. With the loop, scrape a portion of colony off the agar
plate surface and spread the sample with the distilled water drop on the slide. Do
not to mix the drops on the slide. Reheat the loop and continue the same procedure
for each of the samples of bacterium, transferring a total of four samples onto the
two slides. Let the slide dry at air temperature.
3. When dry gently heat the slide by passing it through a low flame two times. This is
known as heat fixing and the bacterial cells will adhere to the slide surface.
4. Protect your hands from the stain by wearing gloves provided. Place a drop of
crystal violet on each bacterial sample. After one minute, rinse the slide with a
gentle flow of water.
5. Next add a drop of Gram’s iodine reagent. After one minute rinse with water.
6. Using a bottle of acid alcohol (20% acetone in Ethanol) and gently drop the alcohol
on the stained area until the solvent running off is colorless. Rinse the slide with
water.
7. Place a drop of safranin on the surface. Let stand for 1 minute. Safranin is a
counterstain that allows you see Gram negative bacterial cells. Rinse slide with
water.
8. Blot the excess water using bibulous paper. Do not press with too much force as the
slide will break. Start with the 4X objective and progress through the other
objectives, finally examining your slides using the oil immersion objective.
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Sketch what you observe from each slide. Note the cell shape and which species was Gram
negative or positive.
Slide B, E
Slide M, S
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Bacterial Shapes
As you can see, bacteria have certain shapes that aid in their identification. Most common
shapes are cocci, which are spherical, some are rod-shaped bacilli and some are a corkscrew shape known as spirilla.
Procedure
1. Obtain prepared slides as indicated by instructor. Using oil immersion, observe the slides
and sketch what you see.
2. Compare your sketches to posters presented in lab.
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Bacterial Habitats
On almost any surface or within any environment you will find certain species of bacteria
that thrive there. Some bacteria live near thermal vents on the sea floor and still others can
live in conditions where there is no oxygen. Some bacteria are even able to live in oil and
use that as a nutrient resource. You will be investigating where bacteria live whether it is in
the classroom, campus, and laboratory or even on your body.
Procedure
Before you begin, formulate a hypothesis for your investigation. State your hypothesis here.
H0:
1. Obtain a sterile swab and determine a sample site.
2. Swab the site by gently rolling the swab across the surface.
3. Obtain a petri dish with agar and gently rub the swab across the surface. If you
would like to sample a different area use another clean swab and save space on the
agar plate.
4. Incubate overnight and look at the petri dishes next lab session.
Bacterial Lab 1 written by
Renae L. Rust, M.S.
June 2010
5
Questions
1. What are some common ways to differentiate between bacterial species? Why is it
difficult to determine species differences?
2. Which of the prepared bacterium was Gram negative? Which was Gram positive? Why is
being able to tell the difference important?
3. If you were given an unknown species of bacterium, how would you go about identifying
it? Would you be able to identify the bacterium down to the species level using the methods
you learned in lab today?
4. For the bacterial swab, explain your observation (why did you choose that sample
site(s)), detail your method, analyze your results (explain colony number, how many
different, etc.) and draw a conclusion. Was your hypothesis rejected or accepted? Type
this up and staple to the lab when turned in.
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BIOS 1130
Protists
Lab 2
Introduction
Protists are ancient eukaryotic organisms and many have evolved single celled complex
structures and life histories. Most protists are unicellular, however, there are several algae
that are colonial and form multicellular structures. Protists inhabit aqueous type
environments that can range from ponds and lakes to moist soil and into hosts. In gaining
nutrients, protists can be predatory where they actively hunt and engulf their food by
phagocytosis. Others absorb their food and are commonly found as either parasites or as
symbionts with other organisms. Still others have the ability to produce their own food
through the process of photosynthesis and contain chloroplasts within their cellular
structure. Protists that are photosynthetic are commonly grouped as algae and protists that
ingest food are called protozoa. These organisms play a large role in many ecosystems,
with algae protists forming the base of the trophic levels in marine and aquatic ecosystems.
The diversity of protists is immense and classification is in a state of flux with the advent of
molecular genetics. In the laboratory we will follow the grouping example shown in Biology
with Physiology, Life on Earth 8th ed., chapter 20, table 20-1. We will be working with several
examples of protists in the lab that represent several groups.
Objectives
1. Study each protest representative and distinguish certain characteristics relevant to
the group.
2. Compare nutrient needs and methods to gain, locomotion and life history of protists.
Protist Representatives
Group…………………………..Representative Genus
Amoebozoans……………….Amoeba
Euglenozoans……………….Euglena
Stramenopiles………………Diatoms
Aleveolates…………………..Paramecium
Spirostomum
Vorticella
Green algae……………….….Various algae
Pond Sample………………...variable
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Procedure
You will be making several slides of protists and observe each using a microscope. Sketch
each protist, write your observations and answer the questions in the space given.
Amoebozoans
Habitat
Amoebas are found in both fresh water and seawater as well as in soil. They generally live as
bottom dwellers and actively hunt for food that includes algae, bacteria, other protozoans,
rotifers and many other microscopic organisms.
Features
Amoebas have an outer cell membrane called the plasmalemma, which has fringed, fine
hairlike projections. These are thought to help the amoeba adhere to a surface as well as
nutrient particles. The cytoplasm enclosed by the plasmalemma and is differentiated into a
thin, peripheral rim of stiff ectoplasm and an inner, more fluid, endoplasm. The ectoplasm
will appear clear (called the hyaline cortex) due to its lack of subcellular organelles. The
endoplasm will contain an abundance of organelles.
The Amoeba will move by changing its shape and thrusting out portions of its cellular body
called pseudopodia. The pseudopodia will anchor to a surface and motile force will pull the
rest of the cell forward. The grasping end of the pseudopodia is called a hyaline cap.
Amoeba Drawing
Sketch Amoeba and note if you see any pseudopodia. Watch the movement for a few
minutes and sketch three sequences of drawings indicating movement and shape at each.
Does amoeba have an anterior or posterior end? Does it change direction and extend
pseudopodia at all points on its body?
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Euglenozoans
Habitat
Euglenas are common in still waters and ponds where there is a rich abundance of organic
matter. Often they give a greenish cast to the water color and can even be found in
extremely wet soil areas.
Features
Euglena is usually pear-shaped with a blunt anterior end. They range 35 – 65 µm in length
and are green in color. Chloroplasts are scattered throughout the cellular body and a
nucleus is located centrally. Euglena is propelled by a flagellum that also allows it to turn
and rotate. When Euglena stop propulsion, their body will contract in place, something
called a euglenoid movement.
The body is covered with a flexible pellicle that is secreted by the clear ectoplasm that
surrounds the endoplasm. The eyespot, or stigma, is a red pigmented spot that shades a
swollen basal area of the flagellum. This is light sensitive, and Euglena will move toward
light conditions ideal for photosynthesis. Euglena maintains osmoregulation with a large
contractile vacuole that empties into a reservoir. Nutrition is holophytic, where
photosynthesis provides nutrition. Extra food is stored in paramylon starch granules
throughout the body and chloroplast areas.
Euglena reproduces by longitudinal fission, and can reproduce in this manner even when
in an encysted state.
Euglena Drawing
Sketch the Euglena, note organelles and label. Use available posters to help identify
organelles.
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Stramenopiles
Habitat
Diatoms can be found in fresh and seawater. The cell wall consists of two valves made of
silica. When a diatom dies, the silica does not disintegrate. It accumulates as sediment and
this is where we harvest diatomaceous earth, a fine powdery material used as abrasive in
some toothpaste and other polishes.
Features
Diatoms have golden-yellow color due to carotenoid and xanthophyll pigments, which
mask the green of chlorophylls present. They form part of phytoplankton, which are single
celled photosynthesizers that are found in the upper portion of lakes and oceans. They are
vital for providing large amounts of oxygen in the atmosphere and form the producer
trophic level in aquatic and marine ecosystems.
Diatom Drawing
Sketch several diatoms. Are they living examples? What part of the cellular body are
you drawing?
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Aleveolates
Habitat
Paramecium are found in fresh, slow moving water that contains vegetation and decaying
organic matter. Spirostomum are found in fresh water, while Vorticella prefers stagnant
ponds and streams, where it clings to vegetation.
Features
Paramecium are slipper shaped, transparent and colorless. Paramecium often appear green
in color as they consume algae and store it in vacuoles, giving them a green color. They are
active and can swim at the rate of 1-3 mm per second. They have an oral groove that
extends obliquely from the anterior end to approximately the middle of the cell body. This
groove opening acts as a mouth and the extension into the body as the gullet. Cilia line this
opening and help in bringing bits of food. Cilia also cover the body and aid in movement.
Spirostomum have a long, cylindroid body with a flattened shape. They possess the fastest
rate of contraction known in any living cell. They have a water expelling vesicle at the rear.
Some species possess cilia for movement.
Vorticella is a solitary sessile (stationary) ciliate. They have a long stalk that can contract
into a spiral shape when disturbed. The body has a bell shape with a flared rim
(peristome). Cilia are found on the peristome and helps filter bits of food into the cell. The
nucleus will have an elongated U-shape as a macronucleus and a smaller micronucleus.
Vorticella can reproduce with fission, but have been seen to bud as well.
Paramecium Drawing
Sketch a detailed drawing of a Paramecium. How does it move? Is it a predator? Does it
have an eye spot?
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Spirostomum Drawing
Sketch a Spirosomum. Do they differ in physical appearance to one another? Why
would rapid contraction be beneficial? Do they move in a direction or stay in one
place?
Vorticella Drawing
Sketch a Vorticella. What is the shape of the cell? Does this change? How does Vorticella
move? How does it gather its food?
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A Sample of Pond Water
Take a sample of water collected from a pond and sketch as many different protists as you
can find. Are there other organisms such as insects present? Did you find any
Paramecium, Euglena, Vorticella? How many different types do you see?
Protist Lab 2
written by
Renae L. Rust, M.S.
June 2010
13
Questions
1. Compare and contrast the varying features of the examples of protists in lab. Make sure to
look at locomotion, food finding strategies, body structure and habitat.
2. State at least one unique feature for each group that defines that group.
3. Which of the protists have asexual reproduction? Which have sexual? Read your text for
further information.
4. What is the benefit to staying anchored versus being able to move freely? Which were
anchored? Which could move freely?
5. How could pseudopodia be helpful or harmful to an amoeba? Does it have cilia to help it
move?
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BIOS 1130
Organization of the Animal Body
Lab 3
Introduction
Multicellular organisms are composed of a complex system of cells that differentiate into
specific tissue types. Examples include epithelial tissues, glands and connective tissues. An
organ can have multiple tissue types where each contributes a specific function that then
adds up to the overall function of the organ itself. Structures of organs include kidneys,
bladder and the stomach. When multiple organs act in concert to the functioning of a
system, this is known as an organ system. The circulatory, digestive and respiratory
systems are each composed of several organs.
Tissues are derived during animal development from three tissue layers: ectoderm,
mesoderm and endoderm. It is from these embryonic tissue layers that all body tissues
develop.
In lab we will be looking at slides representing four categories of tissue types derived from
ectoderm, mesoderm and/or endoderm. These are epithelial tissue, connective tissue,
muscle tissue, and nerve tissue. These tissue types are integrated into organs and usually
all four will be found in a single organ.
Objectives
1. Identify and describe the four main categories of tissues.
2. Identify tissues in mammalian skin.
3. Relate tissue types to organ anatomy.
Epithelial Tissue
Epithelial tissue can be a single layer of cells called simple epithelium or multiple layers of
cells called stratified epithelium. They generally cover or line an external or internal
surface. Epithelial layers may be derived from embryonic ectoderm, mesoderm or
endoderm. If epithelial cells are flat they are called squamous. If they are cube-shaped they
are called cuboidal. Tall, prism shaped cells are called columnar. An important property of
epithelial tissues is that they are constantly replaced by mitotic cell division.
1. Obtain two slides, one showing simple epithelium and another showing stratified
epithelium. Sketch each and label.
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Questions
a. Where can simple epithelium found? Where is stratified epithelium found?
b. Identify the shapes of the cells that are seen on the slides.
c. Why is it that epithelial cells are constantly replaced?
Connective Tissues
Connective tissues have cells that are widely separated by a matrix of extracellular
substances. This matrix contains fluids and flexible protein fibers, the most abundant being
collagen. The cells secrete the protein fibers found in the matrix as well as fluids as needed.
Connective tissues are further categorized into three main categories: loose connective,
fibrous connective and specialized connective tissues. Examples of loose connective
tissues are membranes and skin. Fibrous connective tissues are densely packed and form
tendons and ligaments. Specialized connective tissues include cartilage, bone, fat, blood
and lymph. All connective tissues are derived from the mesoderm.
2. Obtain slides that show loose, fibrous and specialized connective tissues. Sketch and label
each.
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Questions
a. Where can lose connective tissue be found? Fibrous? Specialized?
b. What is another name for the bone cell? What type of deposits do these cells secrete?
c. Why is blood considered to be a connective tissue?
Muscle Tissue
Muscle tissue may be either striated, where you can see a banding pattern, or smooth,
where no banding can be seen. Muscle tissue contracts, causing movement. Striated muscle
tissues include skeletal and cardiac muscle types. The skeletal muscle moves the skeleton
and the diaphragm and is composed of muscle fibers formed by the fusion of several cells
end-to-end. Cardiac muscles, found in the wall of the heart, are attached by intercalated
discs. Smooth muscle is found in the skin and the walls of organs such as the stomach,
intestine, and uterus. Muscle tissue is derived from the mesoderm.
3. Obtain slides for skeletal, cardiac and smooth muscles. Sketch and label.
Questions
a. Which muscle tissue is voluntary? Which is involuntary?
b. What organs have skeletal muscle? What organs have smooth?
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Nervous tissue
Nervous tissue allows for response to stimuli in the external and internal environment.
Nervous tissue is found in the central nervous system which includes the brain and spinal
cord. It also composes the peripheral nervous system, which integrates into every organ
in the body. Nervous tissue is further broken down into neurons, which generate electrical
signals, and glial cells, which support neurons. Nervous tissue is derived from the
ectoderm.
4. Obtain a slide showing a nerve cell and supporting glial cells. Sketch and label the
structures.
Questions
a. Why is nervous tissue found in every organ in the body?
b. What are specific functions of glial cells?
Organ Systems
1. Color the attached organ systems. For each organ system name at least two tissue types
that can be found in that system.
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BIOS 1130
Skeletal Systems
Lab 4
Introduction
Skeletal systems support and protect an animal. They also assist in locomotion by working
with antagonistic muscles, those that work in pairs to contract and relax, giving movement
to a section of the body. There are three main types of skeletal systems: hydrostatic
skeletons, exoskeletons, and endoskeletons. Hydrostatic skeletons use incompressible
fluids suspended in the interior of an animal, worms and mollusks are examples of
hydrostatic skeletons. Antagonistic muscles push the fluid and cause it to flow which causes
movement of the animal body. Exoskeletons cover the exterior of an animal, insects, spiders
and crustaceans. This type of skeleton has varying degrees of thickness and rigidity and is
made of chitin, a sugar polymer. Endoskeletons are found within the animal body and are
found in chordates (vertebrates and notochord animals) and enchinoderms (sea stars).
Objectives
1. Study, compare and be able to describe the three types of skeletal systems.
2. Compare three vertebrate skeletons and identify similar structures and placement.
3. Study bone structure and composition.
Hydrostatic Skeletons
Many invertebrates, such as roundworms, cnidarians and annelids (worms) use fluid and
muscle contractions to move. Circular muscles of a worm contract (pull together) while
longitudinal muscles relax causing a stretching of a worm. If the longitudinal muscles
contract, the circular muscles will relax, causing a “bunching” of the worm.
1. Study the movements of a worm with the dissecting microscope. Sketch the shapes as you
notice the changes. Use tweezers to gently prod the worm and observe it's movements.
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Questions
a. Can you see the flowing movement that indicates fluid within?
b. Is there a transition of long and bunched shaping? Describe.
c. Is the fluid denser as the muscles act upon it?
Exoskeletons
Exoskeletons are characteristic of several phyla, especially Arthropoda. Arthropodans
include spiders, insects, crawfish and millipedes. In addition to support, the exoskeleton
also prevents water loss, aids in protection of soft internal structures and serves as a point
of attachment for internal muscles. The tough shell is composed of chitin, a polysaccharide.
Chitin can be altered in its density and thickness, and at the joint areas a thinning of chitin
occurs which allows flexibility. These are called pleural membranes. Pleural membranes
can also be found on the abdomen, allowing expansion. This type of skeleton is the most
common of animals.
2. Obtain four different insect samples collected from the field. Sketch each and observe
their joints using a dissecting microscope.
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Questions
a. Write the differences you see regarding the hardness of each exoskeleton. Why would it
be beneficial to have a lighter exoskeleton? More dense?
b. Can you see if the exoskeleton changes in thickness around the joint areas? Indicate on
your drawing where you can see this.
c. Do flying insects have harder exoskeletons? Describe the differences between flying
insects and observe whether their wings are covered by the exoskeleton.
Endoskeletons
Endoskeletons are characteristic of vertebrates. They are composed of three connective
tissue types: cartilage, bone and ligament. Cartilage cells (chondrocytes) produce a thick
collagen matrix and are sparsely nourished since there is no direct blood supply. Bone is
composed of calcium phosphate deposits that are added to collagen fibers. Bone has three
types of cells: osteoblasts (that aid in growth), osteocytes (maintenance), and osteoclasts
(break-down of bone). Bones that support limbs consist of a hard, dense area called
compact bone and a more spongy internal area called cancelous bone. At the ends of these
bones is cartilage which aids in smooth movement and cushioning. Inside the bone you will
find a hollow area where marrow (medullary cavity) produces red blood cells and
immune cells. Bones are connected with ligaments (bone-to-bone) and tendons (muscle-tobone). Either end of a long bone is referred to as epiphysis and the mid section as the
diaphysis. Periosteum layers over the bone surface and contain osteoblasts for bone
growth. Growth plates, called epiphyseal disks are seen at the head of the bone and extend
the bone as the animal grows. Small holes in the bone called foramina allow blood vessels
to bring nutrients to bone cells.
3. Obtain a beef leg bone that has been cut longitudinally in half. Sketch the bone and label
as indicated in questions.
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Questions
a. Label the structures: foramina, compact bone, cancerous bone, epiphysis, diaphysis,
medullary cavity, periosteum.
b. What is the benefit of having an integrated blood supply? How would this help if a bone
was broken?
c. Which bone cells are more likely to be present in young animals? Which would be more
present in older animals?
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Skeletal Comparisons
Vertebrates have similar structures, modified over time via natural selection as different
species evolved from a common ancestor. An internal skeleton is composed of an axial
skeleton (head and spine) and an appendicular skeleton (limbs and pelvic area). A
pectoral girdle consists of bones that attach the front limbs to the axial skeleton. A pelvic
girdle consists of the pelvis, which attaches hind limbs to the axial skeleton.
4. Observe the frog, bird and human skeletons. Sketch the areas as indicated in questions.
Questions
a. Compare a bird skeleton and a human skeleton. List and sketch five skeletal differences
associated with locomotion. Explain how each is involved in locomotory movement
(walking, flying).
b. List some of the sketch skeletal differences associated with the locomotion of a frog
versus that of a human. Make a rough sketch to illustrate these differences.
Skeletal Systems Lab 4 written by:
Renae Rust, M.S.
Summer 2010
23
BIOS 1130
Muscles
Lab 5
Introduction
Muscles allow for movement of the animal body and internal components of many organ
systems. They are extensively innervated for control, and hormones can also be used for
further response. Skeletal muscles are responsible for voluntary locomotion and limb
movement. Skeletal muscle cells are long and striated and composed primarily of actin and
myosin protein fibers. These muscles are nearly always found arranged as antagonistic
pairs that move the skeleton by contractions. Muscles that contract to straighten, or
increase an angle at a joint, are called extensors. Muscles that cause a “bend” or decrease in
angle are called flexors. In vertebrates, skeletal muscle is further composed of red and
white muscle types. Red muscle allows for long duration of use (think marathon runner). A
continuous blood supply is provided to maintain a constant source of oxygen, and therefore
energy. White muscle is called “fast acting” muscle and allows for short term, powerful
bursts of contractions due to a large amount of stored glycogen. Lactic acid is produced in
large amounts because of the anaerobic use of the sugars. Smooth muscle is responsible for
the involuntary movement of the gut, blood vessels, pupils and reproductive systems. The
heart is composed of cardiac muscle where the cells are short, branched systems that are
bound by tight junctions where electrical signals spread across cells creating independent
contractions.
Objectives
1. Identify and describe the three main muscle types, skeletal, smooth and cardiac.
2. Study fetal pig muscle structure and relate it to function.
3. Test your muscle strength and compare. (Vernier, grip strength comparison, #16)
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Skeletal Muscle
Skeletal muscle has many nuclei within each cell (multinucleated) with long myofilaments
running lengthwise. The filaments are further divided into actin and myosin protein fibers.
These fibers slide over one another during a muscle contraction. Muscle cells are packaged
into sarcomeres, joined together by tight z-lines at the border of each sarcomere. Notice
the banding patterns that are known as striations.
Obtain a skeletal muscle slide. Sketch and label where nuclei are found and the pattern of
the actin and myosin.
Smooth Muscle
The smooth muscle looks very different from the skeletal muscle. The cells are spindle
shaped and lack striations. Smooth muscle has slow contractile movement that is
controlled by the autonomic nervous system and various hormones.
Obtain a smooth muscle slide. Sketch a smooth muscle cell, note the position of the nuclei,
actin and myosin filaments.
Cardiac Muscle
This muscle type is found in the heart and has branched cells. The cells are connected by
intercalated disks that allow electrical pulses to spread between cells.
Obtain a cardiac muscle slide. Sketch and label where the nuclei are found and look closely
at the pattern of fibers.
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Fetal Pig Dissection
A fetal pig has been dissected for you by your instructor.
Roughly sketch the muscles shown and identify with terms given below.
Internal oblique – abdominal constriction
Deltoideus – aids in flexing humerus
Extensors – extend and rotate wrist and digits
Triceps – upon contraction forelimb extends
Tensor fasciae latae- extends the leg
External oblique – constricts abdomen
Latissimus dorsi – moves foreleg
Trapezius – draws scapula medially
Fetal Pig Sketch
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Questions
1. What similarities of the muscle types share? Do they all have actin and myosin?
2. How does the branching of cardiac muscle help in heart function?
3. From the fetal pig dissection, list the muscles that act as flexors and as extensors.
Why would some muscles have to be large? How do they function in movement?
4. With a partner find and describe at least two antagonistic pairs found on the human
body. If necessary find a poster of human muscle anatomy for help.
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BIOS 1130
Nervous System, part I
Lab 6
Introduction
The function of the nervous system is to detect stimuli and produce a response in the form
of an action or behavior. This is accomplished via electrical currents that travel through and
along special cells called neurons. These are specialized cells that maintain a constant
electrical voltage potential across their membranes. Each neuron is composed of a cell
body, dendrites, axons and a synaptic terminal. The cell body is the “decision” and
integration portion of the cell. Incoming signals from dendrites (projections that are
connected to the cell body), are processed and sent out to the axons (long conductors of the
outgoing signal). At the end of the axon is the synaptic terminal, where the signal is
transmitted another neuron’s dendrite. A synapse can also connect with a muscle or gland
cell. The synapse portion is separated by a gap between the ending axon synaptic terminal
and the receiving dendrite or cell. Specific chemical transmitters will either excite or inhibit
the receiver, thus continuing the electrical signal or ending it. When a neuron is stimulated,
this entire series of events is called an action potential.
There are three types of neurons that affect response and behaviors in organisms. These
are: sensory neurons (which respond to external or internal stimuli), interneurons
(which receive signals from many sources and process the information for proper relay),
and motor neurons (which activate muscles or glands after input from interneurons or
sensory neurons).
Almost all bilateral organisms have clusters of neurons (ganglia), usually sensory, at one
end of the body with nerves, or bundled axons, extended and integrated throughout the
body of the organism. The increasing complexity of an organism gives rise to cephalization
of the ganglia in the head region. The human brain is a complex evolutionary product that
has extensive specialization of ganglia. The human nervous system is composed of a central
nervous system (CNS) and a peripheral nervous system (PNS). The CNS is composed of
the brain and spinal cord. The brain is the main processor and decision maker with input
from internal and external stimuli. The spinal cord is a main-line conductor for incoming
and outgoing electrical signals to and from the brain. The spinal cord is a thick grouping of
axons that integrate into the brain. The PNS consists of nerves and smaller outside ganglia,
innervating the body. The PNS is split into motor neurons (voluntary muscle and gland
communication) and sensory neurons (signals to CNS from sensory neurons). Motor
neurons are divided into the somatic (skeletal muscles) and autonomic nervous system
(involuntary response innervations: heart, smooth muscle, etc.). The autonomic nervous
system is then separated into the sympathetic and parasympathetic divisions. The
sympathetic division handles the “stress” response by getting the body ready to fight or flee.
The parasympathetic division functions during a relaxing time, and directs maintenance and
normal functioning of internal organs. See figure 38-7, Biology with Physiology 8th ed. Life on
Earth, for a summation of the mammalian nervous system organization.
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Objectives
1. Dissect a worm and identify nervous structures.
2. Study a neuron and understand anatomy and electrical signal initiation and
pathway.
3. Study a model of the spinal cord and identify sensory nerve input and nerve output.
4. Study the anatomy of a brain and identify and understand structures as indicated.
5. Engage your frontal and temporal lobes with problem solving and memorization.
1. Worm Dissection
Procedure
1. Obtain a worm, dissecting pan and scalpel.
2. Carefully cut the worm from end to end, cutting just the skin and not tissue
3. Pin the worm open using the skin, clear the central portion of tissue.
4. Sketch and identify the cerebral ganglion, subpharyngeal ganglion and ventral
nerves. Example pictures can be seen in the lab.
29
2. Neuron Anatomy and Signal Conduction
Procedure
1. Using a microscope, look at the neuron slide and compare it to the poster on display.
Sketch a neuron, label and describe these structures: dendrites, cell body, axon,
synaptic terminal, node, myelin cell (swan cell).
2. Describe the events and indicate in your sketch the process of an action potential by
labeling the voltage in the cell body during resting potential, threshold, action
potential back to resting potential. You can find this described on page 763 in
your text and also by looking at figure 38-2.
Questions (answer on a separate sheet of paper)
a. What is the purpose of the myelin cell? What is the purpose of nodes?
b. What conducts signals faster, a thick or thin axon?
c. What can cause conduction to be even faster for a neuron?
d. What two neurotransmitters might be released from a synaptic terminal?
e. What molecules and ions are responsible for negative and positive charges? What
charge is held in greater concentration within the cell during resting potential?
30
3. Spinal Cord
Procedure
1. Study the model of the spinal cord and sketch.
2. Label and describe these areas: white matter, central canal, gray matter, dorsal
root, dorsal root ganglion, ventral root, peripheral nerve. Page 773 in your text
can help with this.
The spinal cord can handle simple reflexes that are immediate and might take too long for
the brain to process. It also can send a instant command to a given signal. A common
example is the pain-withdrawal reflex arc. Here, a signal of pain is detected by a sensory
receptor and is relayed through the dorsal root and into the spinal column. There an
interneuron takes over and immediately sends a response to the motor neuron which in
turn, stimulates the muscle. This response is rapid. The same signal is sent to the brain via
the spinal cord at the same time, but the response is delayed. This allows for further
correction after the initial response, even to the point that the quick response can be
overridden.
Questions (answer on a separate sheet of paper)
a. Is the dorsal root ganglion part of the PNS or CNS? What type of neuron is it?
b. How and why is the spinal cord protected?
c. Where do you find interneurons within the spinal cord?
d. What is the purpose of a reflex arc?
31
4. The Brain
Procedure
1. Study and sketch the brain from the model in lab.
2. Label and describe these areas: hindbrain, cerebellum, pons, medulla, midbrain,
forebrain, thalamus, limbic system, cerebral cortex.
3. For the cerebral cortex area, label these areas: frontal lobe, parietal lobe, occipital
lobe, temporal lobe.
32
5. Problem Solving and Memorization
Procedure
1. For one minute study the string of numbers as shown in the next page of this lab, then
write what you remember without looking again. Record your answer here.
2. Look at the five riddles in lab and write your answers here.
3. Listen to your partner read the paragraph given in lab. When they are done, write down
the first and last word of the paragraph here.
Nervous System Lab 6
Written By:
Renae L. Rust M.S.
For Metropolitan Community College
Summer 2010
33
Number Sequence
276489730879200986453886289119922000064738294762524
Riddles
1. What can fill a room but takes up no space?
2. What has a mouth but cannot eat what moves but has no legs and what has a bank but
cannot put money in it?
3. If a rooster laid a brown egg and a white egg, what kind of chicks would hatch?
4. How many times can you subtract the number 5 from 25?
5. If you have it, you want to share it. If you share it, you don't have it. What is it?
Paragraph
“Damage to the cortex from trauma, stroke, or a tumor results in specific deficits such as
problems with speech, difficulty reading, or the inability to sense or move specific parts of
the body. Most brain cells of adults cannot be replaced, so if a brain region is destroyed,
these deficits may be permanent. Fortunately, however, training can sometimes allow
undamaged regions of the cortex to take control over and restore some of the lost
functions.” (Audesirk, et. al. 2008)
34
BIOS 1130
Nervous System, part II
Lab 7
Introduction
The body processes outside stimuli in a variety of ways. We can hear, taste, feel, see or smell
the outside environment and respond to it appropriately. This is known as the sensory
system, and depending on the species, these senses can be simple or highly complex.
Sensory receptors are entire specialized cells (most often neurons) that produce electrical
signals in response to the outside environment. Common sensory receptors are
thermoreceptors (temperatures), mechanoreceptors (touch, pressure), photoreceptors
(light), chemoreceptors (smell and taste) and pain receptors. For vision, light passes
through the cornea and lens and is focused on the retina. On the retina, photoreceptors,
rods and cones gather light and pass an electrical signal to the optic nerve. The ear is
shaped to convert sound waves into electrical signals. Sound vibrations move hair cells that
turn movement into an electrical signal passed to the auditory nerve. Sound is measured in
decibels, and sounds above 80-100 decibels damage these hair cells permanently. Taste is
sensed by taste receptor cells organized in clusters of taste buds. These cells are bathed in
saliva solution that helps to dissolve foods. As the food is dissolved, special proteins bind to
molecules and produce an electrical signal.
Objectives
1. Dissect a sheep eye, identify structures and their function.
2. Explore the function of rods and cones.
3. Observe the inner ear and understand it functions.
4. Test neuromuscular reflexes (Vernier Physiology, 14B).
35
Anatomy of the Eye
Obtain a sheep eye and dissecting tools. Be sure to wear gloves. You may need to cut away
some muscle and membrane to expose the eye in order to cut it longitudinally. Once you
have two halves, place them in a shallow dish with some water. Sketch and identify parts
listed below and use your textbook, models, posters and notes to write function of the parts
next to the label.
Optic nerve, sclera, choroid, retina, cornea, lens, ciliary muscles, iris, pupil, vitreous
humor, aqueous humor, blind spot, macula lutea, fovea
Eye
After images experiment
The retina in human eyes is composed mainly of rods and cones varying in densities. Rods
sense light at any wavelength and work well even in dim light, but do not relay color.
Therefore they are only sensitive to the intensity of light. Cones sense specific wavelengths
of light and detailed information about the light. This gives cones the ability resolve specific
colors. This is why we can see details better than most species. The cones only process small
amounts of light and are densely packed in the fovea where incoming light is focused. Cones
perceive three types of color; red, green and blue. When an intense color is focused on for a
short time, the cones for that color, or color mix, will “bleach out”. If you focus on a white
screen afterwards you will see a complementary color afterimage until the bleached out
cones recover.
The instructor will show 3 color shapes (red, blue and green) on the screen in a dark
classroom, with a white screen shown after each color. Stare at the shapes for 20-30
seconds each and then immediately flip to a white screen. After each color slide, record the
color of the afterimage.
Slide Red _______________________
Slide Blue_______________________
Slide Green ______________________
36
Questions (answer on a separate sheet of paper)
1. Which set of cones were functioning after the red image? Blue? Green?
2. What do color do you predict to see if you stare at a purple image? Why?
Anatomy of the Ear
The ear not only allows for perception of sound, it can also call tell us the direction of sound,
the pitch (frequency), and loudness. The ear senses tremendous amounts of information
from sound alone and even has semicircular canals to determine spatial orientation. This
helps your brain determine if you are up, down, right, left and backwards and forwards. The
fluid in the canals will move with acceleration and hairs within the canals are able to sense
this change and convey the information to the brain. This is how spinning in circles can
confuse your senses for a short time.
Observe the model of the human ear and posters if available. Sketch and label the parts of
the ear using the terms listed below. Use your text, notes, and poster descriptions form lab
to explain the function for each.
Tympanic membrane, auditory ossicles, oval window, cochlea, malleus, incus, stapes,
vestibular canal, tympanic canal, round window, basilar membrane, organ of Corti,
tectorial membrane
Ear sketch
37
BIOS 1130
Nutrition and Digestion, Part I
Lab 8
Introduction
As living organisms we need nutrients in order to function. Nutrients include lipids,
carbohydrates, proteins, minerals, vitamins and water. These nutrients provide the
necessary energy needs and building materials to maintain cellular processes. The two
nutrients that are our main energy source are lipids and carbohydrates. Proteins are also
an energy source, although the metabolic pathway that converts protein to energy is more
complex than that of carbohydrates and lipids. When energy is released from these two
main energy sources, a certain amount of energy contained within is released. This is
measured as a calorie. A calorie is the amount of energy required to raise the temperature
of 1 gram of water by 1 degree Celsius. The caloric content in food is measured in
kilocalories (1000 calories) and is often noted with a capital “C” on packages (i.e. 1
kilocalorie = 1000 calories = 1 Calorie). The average human body needs 2000 Calories per
day to maintain metabolic activity and normal function. A person at rest burns 70 Calories
per hour. If we consume more than the calories needed per day we store the excess in the
form of fat. Each pound of fat has an average 3600 Calories. Fat storage is an important
adaptation for most organisms. Food can be ephemeral for most organisms, meaning that it
is unpredictable as to when, where and how much will be found. Therefore being able to
store excess food is imperative in most species.
Objectives
1. To explore metabolic activity, fat storage and caloric needs for a human.
2. To explore and compare the amount of calories in food samples.
38
Caloric Intake
1. You are going to estimate a typical day of energy use and intake. Use the table provided in
lab to calculate the number of calories you consumed for a 24 hour period. Next to that
write your general activity levels (pg. 686, table 34-1). Fill in the following table.
Table 1.
Food Consumed
Calorie Intake: _________
Calories
Activity
Calories burned
Calorie Use: __________ Difference: ________
Calculate the predicted metabolic rate (MR) for the average person. This is called the
Harris-Benedict Equation.
Females: 665 + (Weight, pounds x 4.35) + (Height, in. x 4.7) – (Age, years x 4.7) =_____
Males: 66 + (Weight, pounds x 6.23) + (Height, in. x 12.7) – (Age, years x 6.8) =______
Multiply this result by the factor that represents your typical activity level:
Sedentary (little or no exercise): 1.2
Light Activity (walking, some movement 1-3 times per week): 1.375
Moderate activity (walking, run 3-5 times per week): 1.55
Very active (running, basketball 6-7 times per week: 1.725
Extreme activity (daily hard exercise one or more hours per day): 1.9
Predicted MR calculated: ______________
39
Body-Mass Index
Calculate your body mass index (BMI) with the following equation and compare it to the
chart provided in lab. This is an obesity index and gives general guidelines on where an
average person stands for body fat mass. People that are weightlifters or have demanding
physical activities will have distorted BMIs and this should be taken into consideration.
BMI = Weight: lb. x 0.45 kg/lb./Height: (in. x 0.0254 m/in)2 = _______________
Questions
a. What is your MR? Do you consume more calories than needed? What is your BMI?
Calculate the ideal MR for your body (i.e. if your weight was ideal according to the BMI) and
write down the number.
b. How far away are you from an ideal weight? If you maintained your caloric intake
calculated from Table 1, what will be your weight 1 year from now? Remember it takes
3600 excess calories to create 1 lb of fat.
c. What activities could you do to maintain, lose or gain weight? Calculate a week of caloric
intake and a week of activity that burns calories and write the total here.
Calories in Food
2. Conduct “Energy in Food”, Vernier lab 1.1 from Biology with Computers.
40
BIOS 1130
Nutrition and Digestion, part II
Lab 9
Introduction
The digestive system developed for the breakdown and absorption of nutrients vital to
survival. Diversity of organisms has led to a diversity of food acquiring adaptations, and
ranges from the simple cellular level to a multi-organ system. Regardless of the complexity
however, all digestive systems accomplish five tasks during digestion: 1) Ingestion,
2) Mechanical breakdown of food, 3) Chemical breakdown, 4) Absorption,
5) Elimination of waste. Depending on the organism and its nutritional needs, these five
steps vary. In a simple organism such as a sponge, digestion occurs at the cellular level and
small particles of food are taken into cells by phagocytosis. Within each cell, absorption of
nutrient occurs and waste is eliminated by exocytosis. In more complex organisms that are
adapted to larger sizes of food, extracellular digestion occurs in a gastrovascular cavity.
Here the food is taken in through an opening (mouth) and placed in a hollow sac-like area
(cavity) where digestive enzymes are released by surrounding cells and chemical breakdown of the food is accomplished. Nutrients are then absorbed by special cells lining the
cavity. Any undigested pieces are expelled out of the same mouth. In this example there is
only one opening for both ingestion and elimination. For animals that have to feed
frequently and take in food multiple times a day in order to survive, a highly complex tube
has evolved. There is an opening for ingestion and a separate opening for elimination. In
between these two points can be a varying complexity of tissue and organ specializations
that process food. In all animals with tube digestion, an orderly system occurs to process
this food. This includes initial physical grinding of food, enzymatic breakdown (chemical)
during extracellular digestion and absorption of nutrients.
Complex animals such as mammals and birds have unique digestion adaptations for the
foods they acquire. Herbivores such as cows and sheep have several chambers to digest the
fibrous cellulose found in plants. The tube includes special compartments with digestive
bacteria and microorganisms to aid in digestion. The intestinal area is extremely long to aid
in as much absorption as possible from a food source that is resistant to breaking down.
Carnivores have a shorter intestinal area because their main food source is protein, which
is more easily broken down than cellulose. In either case these animals have digestive
adaptations that facilitate digestion of their particular foods. These include teeth structures,
stomach compartments, microorganism relationships, intestinal length and elimination
structures. Birds have gizzards that serve as the mechanical breakdown of ingested food
and can be compared to the teeth of herbivore and carnivore mammals. They also have a
multipurpose cloaca, which functions as a site for fecal elimination and reproduction.
Animals that eat both plant and animal matter are called omnivores, and they have a
combined similarity of digestive structures of herbivores and carnivores.
41
Objectives
1. Observing and comparing several digestive structures unique to vertebrates.
2. Study the mammal digestive system.
Comparison Digestion Structures
1. In lab are several skulls from various vertebrate animals. Find a skull of an omnivore,
herbivore and carnivore. Sketch the teeth, which are the first step in breaking down
foods.
Questions
a. For each skull explain why the teeth are shaped different from the others. Which of these
animals has features that allow them to ingest meat and plant matter? What dental
structures allow for this?
b. Why can’t carnivores crush plant material? Why can’t herbivores pierce and kill other
animals?
c. What other physical structures apart from teeth allow for the initial acquisition of
nutrients?
42
Mammalian Digestive Structures
2. Obtain prepared microscope slides for these structures as available in lab:
Salivary glands
Pharynx
Esophagus
Liver
Stomach
Gallbladder
Pancreas
Small intestine
Large intestine
Rectum
Choose three slides to sketch and label. NEXT go to the model of a human and sketch EACH
structure listed above and next to the sketch explain the function of each. Now go the fetal
pig and sketch the liver, stomach and small intestine. You may need to sketch on a separate
piece of paper.
43
Questions
a. Do the cells change in size and shape in the digestive system? From the slides that you
chose explain how those cells function.
b. What is the difference between the human and fetal pig in digestive structures you were
asked to sketch? Are their diets the similar?
c. What digestive structures have enzymes? Name the enzymes that are responsible for the
breakdown of proteins, fats, and carbohydrates.
d. What structures have an acidic solution? What structures have a basic solution? Why is
this important?
e. Observe the slide and model of the stomach ulcer and explain how ulcers develop.
f. Observe gallstones in lab. How did they form?
44
BIOS 1130
Urinary Systems
Lab 10
Introduction
The urinary systems functions to maintain a complex balance of water, salts, ions, nutrients
and blood pressure. In vertebrates the urinary system maintains homeostasis and
regulates the osmolarity of ions such as sodium, potassium, chlorine and calcium. A strict
water balance must also be kept as well as blood pH, glucose and amino acids. It also
secretes hormones, cellular waste and urea. The urinary system therefore is a filtration
system that excretes and reabsorbs to maintain balance in the system. An especially
important function of the urinary system is to deal with nitrogenous wastes created by
digesting protein. As the protein is digested, toxic ammonia is produced by the cells. The
blood will carry this waste to the liver where it is converted to harmless urea that is soluble
in water. From there it is filtered out by the kidneys and excreted. Structures of the human
urinary system include renal arteries, kidneys, renal vein, ureter, bladder and urethra.
In fish, the use of gills and active transport proteins that take in salt against a concentration
gradient is also part of their urinary system. Today you will be dissecting a fetal pig and a
fish and comparing the two different systems.
Objectives
a. Dissect fish and fetal pig and study and compare urinary systems.
b. Observe posters and models in lab of kidneys and nephron structures.
45
Fetal Pig
The instructor will demonstrate dissection of fetal pig. Identify the structures listed below
and use text, lab resources and notes to describe the function next to each term. You do not
have to sketch this system. Use the kidney and nephron models for additional
identification.
Renal arteries –
Renal veins –
Ureter –
Urinary bladder –
Urethra –
Calyxes –
Kidney –
NephronGlomeruli –
Bowman’s capsules –
Loop of Henle –
Proximal tubule –
Distal tubule –
Collecting duct -
Fish Dissection
Obtain a fish for dissection. Cut the fish along the midventral line from the anal region to the
pelvic fins. This will be a tough cut, try not to cut the internal organs. Make transverse cuts
on either end of bottom cut to open the side of the fish so all internal organs can be viewed.
Using the poster, notes, your text and resource texts in lab identify the gills and kidney.
46
Questions
1. List the steps of filtration for the mammalian and fish kidney systems. Name two
similarities and two differences for each.
2. Why do land vertebrate need to conserve water?
3. For a desert land animal the Loops of Henle that extend into the renal medulla are
longer in length than those found in humans. Why is this?
47
BIOS 1130
Homeostasis
Lab 11
Introduction
Animals regulate their internal environment in order to maintain optimal cell function
despite harsh physical and chemical conditions in their environment. At all times a body
has to function within a narrow range of temperature, water, salts, glucose, pH, carbon
dioxide and oxygen levels. Without constant monitoring and adjustment of these levels
many metabolic activities would either quickly run out of energy or denature vital enzymes,
causing system failures. The process by which a body maintains a narrow range of
conditions optimal for cellular function is called homeostasis. Many animals have adapted
to harsh environmental conditions by evolving a dynamic series of systems that maintain
homeostasis and rely on negative feedback loops to turn the systems on and off.
One aspect of homeostasis is temperature regulation adaptations. A narrow range of
intercellular temperature must to be maintained by organisms so that cells can adequately
use ATP, facilitate metabolic reactions of molecular breakdown and building, and to
maintain the hydrogen bonds found in proteins. As temperature increases metabolic
activity increases and energy use increases. Some organisms have adapted to rely upon
external temperatures to maintain internal temperatures, and actively seek warmer and
cooler areas in their environment to maintain an optimal temperature range with least
fluctuation. These types of animals are called ectotherms and include insects, fish, reptiles
and arthropods. These animals have a series of unique behaviors that allow them to
respond to the external environment in order to maintain internal temperature parameters.
Other animals are able to maintain a relatively constant internal optimal temperature and
have adapted to adjust temperature internally and expel heat or generate heat as needed.
These are known as endotherms. Endothermic animals require large amounts of energy to
maintain their internal heat and have adapted to take in large amounts of food. This is in
contrast to ectotherms which rely on the environment to take care of their temperature
needs.
Objectives:
1. To study ectotherm and endotherm temperature recovery rates.
2. To compare the two systems and understand the differences and similarities
between the adaptations for temperature regulation and homeostasis.
48
1. Ectotherm Recovery Rate
We are going to be freezing insects and observing recovery rates for several time intervals
(15, 30, and 60 minutes). Will the varying time intervals affect recovery rates of
temperature homeostasis? Write your hypothesis here:
Ho:
Procedure
1. Collect a total of 10 sweep net insect baggies.
2. Place all baggies in the freezer (even distribution) and take temperature of freezer.
3. Allow the baggies to remain in the freezer for 2 minutes.
4. Remove baggies and bring to lab room.
We will have to be quick about the next step…
5. Place insects on large plastic trays and separate from vegetation.
6. Sort insects into 3 total groups – SMALL, MEDIUM, LARGE. Normally we would measure
each insect and determine a length range and cutoff. However, time will not permit, so
this part is subjective. Have ONE person determine sizes to reduce error. We will pool
our collections into 3 large trays, one for SMALL, one for MEDIUM, and one for LARGE
insects.
7. The instructor will count an even number of insects for each tray and set aside the rest.
8. The insects will be placed in baggies and placed into the freezer for a 2 minute interval.
Record ambient air temperature in lab and record in table.
9. After 2 minutes, remove insects from freezer and immediately count the number of
active and inactive insects. Wait 5 minutes and count again. Record both values in table.
10. Repeat the freezing process again, but extend the freezer time to a total of 5 minutes.
Record beginning and end of 5 minute numbers again.
11. Repeat again for 7 minutes of freezing time.
12.
Table 1. Insect numbers and time intervals.
49
2. Endotherm Recovery Rates
Complete “Effect of Vascularity on Skin Temperature Recovery”, Vernier lab 16A from
Biology with Computers. Answer all questions
Questions. Graph and answer questions.
1. On a separate piece of paper, graph the insect Table 1. Place all 3 lines onto same
graph. Time will be on x-axis and insect number on y-axis. Use the entire graph
paper, label it as Figure 1, and add description. Title graph appropriately and write
your name and date on upper right corner.
2. Did you support your hypothesis for the ectotherm recovery rates? Did it take them
longer to revive as time increases? Would endotherms recover faster than the
insects if under same conditions? Infer this from the Vernier lab for comparison.
3. Which animal (ectotherm or endotherm) has to have a more constant environment?
Give an example of an ectotherm in a highly variable environment. What resource
other than temperature is necessary to life?
50
51
BIOS 1130
Circulatory System
Lab 12
Introduction
Cells need a constant supply of gases, nutrients and the ability to dispose of waste products
from metabolic activities. Simple animals such as sponges are able to use the external sea
environment as a “highway”, using sea water to move vital elements in and out of their cells
through special pores. More complex organisms have developed an internal solution that
successfully transports gases, nutrients and wastes. This is known as the circulatory system
and is made up of three major parts in all complex organisms:



A fluid, blood, which is a connective tissue and is the main transport system
Blood vessels, which are the containment walls for the blood to travel through
A heart, which is a pump that squeezes the blood through the vessels
A circulatory system can be open, such as seen in insects and other arthropods, or closed,
which is found in all vertebrates. It’s important to note that the more complex an organism,
the more complex the pump of the circulatory system. A vertebrate circulatory system has
several diverse functions to support organs, organ systems and cells. These are:
 Transport of gases, wastes, hormones and nutrients
 Regulation of body temperature
 Prevention of blood loss
 Protection of the body from microbes (immune system)
The blood, a connective tissue, circulates within a closed system and consists of plasma, red
blood cells, white blood cells, platelets and transported substances for cellular functions.
Objectives
1. Study and compare various animal heart models
2. Dissect a sheep heart and identify the structures within
3. Look at blood smears to observe the components of blood
52
Heart Models
Observe the vertebrate heart models displayed in the laboratory. Label and sketch the
internal structures of each model in the following space.
Questions
a. List the animal heart models by increasing complexity.
b. Why would there be a complete separation of chambers in the mammalian hearts?
c. Why do ectothermic animals have an incomplete separation of chambers?
d. In each heart label the ventricle, atrium and FLOW directions.
53
Heart Dissection
Obtain a heart for dissection and carefully make a cut along the pulmonary trunk to the
right ventricle (cut in half to see structures). Sketch the heart and identify the semilunar
valves and atrioventricular valves. When are each open? Closed?
You will see chordate tendinae (fine fibers) attached to the valves. These help prevent
valve flaps from “blowing back” from the high pressures developed when the ventricles
contract.
Identify the pulmonary veins and pulmonary artery. Which has oxygenated blood?
Identify the aorta and areas where the Purkinje fibers would be located. What is the
relationship between the two?
Trace the cycle of blood through the heart and write the steps here and show as arrow
directions with step numbers next to them on your drawing.
Blood Components
Obtain a blood slide and place under a microscope. Sketch and identify structures. Use the
posters to identify structures.
54
BIOS 1130
Immune System
Lab 13
Introduction
Pathogens or disease causing microbes, invade our bodies every day. These include viruses,
bacteria, parasites, fungi and protists. Animals have developed protective defenses against
these harmful microbes. These defenses include external barriers, internal defenses and
specific internal defenses. The skin is an external barrier as well as mucous membranes,
hair and secretions of fluid. White blood cells are found in the blood and respond to sites of
injury to engulf foreign particles. In an immune response, certain immune cells will
specifically target harmful microbes and “remember” the invader. Each line of defense
prevents an organism from constant exposure to environmental pathogens that ultimately
cause disease and death.
Today in lab you will be going online to http://www.cellsalive.com/toc_immun.htm. You
will explore pathogens and the functions of each aspect of the defenses against them in a
vertebrate. Explore each section and answer questions here and take the quiz presented at
the web site. Repeat the quiz until you answer all questions correctly. Write the correct
answers in the area provided here.
Questions
1. Which of the subject areas highlights an external defense barrier? Internal defense?
Specific internal defense?
2. Which is most destructive to our immune defenses? Why is it so destructive?
3. Which of these areas would have phagocytes and macrophages?
4. Describe the allergen reaction and why the reactions can be severe.
5. What is an antibody?
6. What is an antigen?
55
Correct answers for Quiz
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
56
BIOS 1130
Endocrine System
Lab 14
Introduction
The endocrine system is a complex array of communications between cells in response to
external environmental and internal stimuli. Imagine not getting a jolt of fear when you
happen upon a bear in the woods, or if you could not grow into an adult. Certain molecules
that are released by cells have the ability to carry messages between your cells. These
molecules can work locally, travel long distances or bridge a very short gap, as with neuron
transmitters. These hormones are responsible for physical, behavioral and homeostatic
responses and balances in your body. Endocrine hormones are released into the blood to
either travel long distances or short, but they are specific for certain cells and cause a
change due to the interaction. Endocrine hormones come from a specific cluster of cells
called glands and are not produced by all cells of the body. There are organ systems that
secrete endocrine hormones in response to stimuli, and in lab we will be studying several of
these systems.
There are three classes of vertebrate endocrine hormones:
Peptide – chains of amino acids
Peptide and amino acid hormones – hydrophilic – bind to receptors – transforms and
begins effect – second messenger – fast acting hormones usually, cause physical or
behavioral response to stimuli
Steroids – hydrophobic – go through the plasma membrane and bind to cytosol proteins or
DNA for gene regulation – can attach to some membrane surface receptors – long term
effects
Objectives
1. To study models of endocrine glands and identify certain hormones produced and
their functions.
2. To investigate endocrine disruption by researching scientific journals for an article
on endocrine disruption.
57
Mammalian endocrine system
Two basic types of glands –
 Exocrine secretes to outside and digestive tract – saliva, sweat, tears, milk, pancreas
and digestion-these have ducts to travel through.
 Endocrine secretes inside body (blood) – ductless, mass exodus, only certain masses
of cells.
1. Endocrine hormone glands
Find the following endocrine glands on the models provided in lab. Sketch the body,
indicating the location of each gland. List the hormones they excrete and its main function.
Hypothalamus
Pituitary
Thyroid-parathyroid
Pancreas
Sex organs
Adrenal glands
58
2. Endocrine Disruption
Find a scientific journal article on endocrine disruption. Your instructor will demonstrate
how to search online for articles.
Print article and attach to your lab and turn it in. Write a 1 page, double spaced, 12 point
font size summary attached with the article that you write. Include the hypothesis at the
top and your summary below that. Include your name, date, lab number on the paper.
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BIOS 1130
Animal Reproduction
Lab 15
Introduction
In reproduction, animals pass their DNA to offspring, continuing genetic lineage. This
process maintains balance in ecosystems, given that each population serves a functional
role. In order to replace themselves animals must undergo a cellular process that produces
either a haploid or diploid cell. Through cellular division offspring are formed and the
process repeats again. Animals either reproduce asexually (without a combination of DNA
from another animal) or sexually (a combination of DNA either from itself or with another
animal). Asexual methods use mitosis to regenerate offspring, buds, or new body parts.
Fission is the process of producing a regenerated limb or new offspring through mitosis. A
unique form of reproduction is parthenogenesis, where a female produces haploid
gametes through meiosis but does not fertilize. Offspring from this animal would be haploid
from a diploid mother. In sexually reproducing organisms a male and female will
recombine DNA and produce unique individual offspring. Fertilization, the process of a male
and female gamete combining, can occur outside the animal (in a wet environment) or
within the animal. Spawning is the process of releasing gametes into the aqueous
environment and by chance they will recombine. Fish and amphibians are common
examples of the spawning method. Internal fertilization occurs when sperm is placed
within the female reproductive tract where the egg will be fertilized. Mammals use internal
fertilization, and can include a complex series of behaviors, temporal signals or chemical
signals to initial sexual reproduction in the male and female. Humans have the ability to
reproduce at any time and have paired gonads, paired organs that produce gametes. These
structures also release hormones that affect the timing of puberty and gamete production
cycles.
Objectives
1. Study the anatomy of male and female pig reproductive structures
2. Compare the anatomy of human male and female structures from lab models and
posters
3. Compare slides of reproductive structures for cellular structural differences
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Male and Female Fetal Pig Reproductive System
Obtain a fetal pig for your group and determine if it is male or female by observing external
structures. Use posters to help you identify each. Follow the instructions and answer the
questions for the gender of your pig.
Male System
Locate the testes by first finding the inguinal canal. Using the diagram provided identify
the epididymis, vas deferens and penis. Sketch the general shape of each structure and
label. Locate the seminal vesicle, bulbourethral gland and sketch and label.
Questions
a. What are produced in the testis? Describe the maturation of sperm beginning with
spermatagonia and list accessory cells.
b. What are the functions of the seminal vesicles and bulbourethral gland?
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Female System
Locate the small bean shaped ovaries on the dorsal wall of the abdominal cavity near the
kidneys. Use the diagram to help. Find and locate the uterus and vagina. Sketch and label
each structure.
Questions
a. What structure on the ovaries allow for the egg to travel to the uterus? Describe the
process of oogenesis and name structures associated.
b. What hormones influence the egg maturation cycle? What hormones are released by
the corpus luteum?
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Human Reproduction Comparison
1. Identify the gonads on models in lab. List the gonad structures.
2. What are the major differences in gamete formation between male and female?
3. What hormones influence the male reproductive structures? What hormones
influence female reproductive structures
4. Which has a negative feedback system to control gamete formation? Which has a
positive feedback during reproduction?
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Slide Study and Comparison
1. Obtain a sperm slide and a mature ova slide. Sketch each and explain the cellular
differences (i.e. cell components included, physical structure, etc.)
a. What gamete cycle ends with one functional cell? Why is there only one produced?
2. Obtain a testis slide and an ovary slide. Sketch each and note the differences.
b. Which organ has a continuous gamete production cycle? Why is the menstruation
cycle every 28 days?
3. Obtain oviduct and vas deferens slides. Sketch each and note the differences.
c. What does the oviduct do? What is the function of the vas deferens?
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BIOS 1130
Plant Anatomy
Lab 16
Introduction
Flowering plants, or angiosperms, are present in all biospheres and dominate many
ecosystems as the main plant type. Flowers are reproductive structures that are more
complex than gymnosperms in their cycle and have helped angiosperms to flourish.
Flowering plants are further separated into monocots and dicots. Features of monocots
include parallel veins in leaf, narrow leaf shape with smooth edges. Examples of monocots
include grasses, corn, orchids and lilies. Dicots have netlike veins in their leaves and a more
broad leaf shape with varying edges. Examples include deciduous trees (maples, oaks),
bushes and many types of bushy wildflowers. All angiosperms have two major body
regions, the root system and shoot system. Each system has a specific function and is
derived from meristematic cells. These cells give rise to three main tissue types: the
dermal tissue system which covers the outer surface of the plant body, the ground tissue
system which includes the main body of the plant, and the vascular tissue system which
transports fluids and nutrients within the plant body. Each of these tissue systems has
further cellular differentiation (see table 24.1 included with lab).
The organs of woody and herbaceous angiosperms are leaves, roots and stems. Each has
unique specializations for the niche to which they are adapted. Leaves consist of blades
and petioles and are the main site of photosynthesis. They also conduct water and nutrients.
Stems support and elevate the plant while also conducting water and nutrients through the
plant body. Stems have four types of tissues, epidermis, cortex, pith and vascular tissues.
Stems also contain meristematic cells which give rise to leaves and branches at nodes.
In woody plants a secondary growth occurs in the stem and produces the rigid structures
of wood and bark. This growth occurs in two lateral meristems called vascular cambium
and cork cambium. In essence, new vascular tissue, phloem and xylem are layered laterally
and the old vascular tissue hardens. We witness this growth as tree rings. The living
phloem and xylem cells are located on the outermost layer of the plant. A tree can be killed
by “girdling” where a strip of bark is cut out around the tree trunk.
Objectives
1. Identify plant structures and types of tissue that compose structures and describe
function
2. Differentiate between monocots and dicots
3. Identify woody plant stem structure and describe growth pattern of rings and how
bark is formed
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Plant Structure and Tissue Types
Obtain a fresh cut flower and identify if it is a monocot or dicot. Sketch the basic structure
and label the shoot system and root system (which might not be with plant, but label
where it would be). Label the leaf, petiole, flower, stem, nodes and terminal bud. Label
where the ground tissue, dermal tissue and vascular tissue are located.
Obtain slides that show a cross section a leaf, root and stem. Compare slides for cucumber,
corn and Tila. Sketch the cells.
Questions
a. Where is meristematic tissue located? What two types are found along nodes and
what type at terminal bud? What is its function?
b. What is the function of the dermal tissue? What three cells are common in ground
tissue? What are their functions?
c. Cut a cross section of your plant stem and see if you can find the xylem and phloem
arrangement. What is the arrangement for this type of angiosperm? What is the
function of xylem and phloem?
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Monocots and Dicots
Look at the dried plants collected from Allwine Prairie. List which are dicots and which are
monocots. What characteristics do you use to tell difference?
Dicots
Monocots
Observe the root structures in lab. Which are monocot and which are dicot? What are the
characteristics of each? What might be the advantage of each?
Tree Rings and Growth
Observe the tree ring model in lab.
1.
Note the rings might be wide or narrow. What causes this?
2. What is secondary growth? Describe the process of xylem and phloem growth and
how this contributes to woody plant structures.
3.
What is the heartwood in the center composed of? Where is the sapwood located?
See figure 42-12 in your text for help.
4. What is periderm? How does bark form?
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BIOS 1130
Plant Responses to Environment
Lab 17
Introduction
Plants have evolved complex chemical signals (by way of molecular hormones) in order to
respond to environmental stimulus. It is important that a plant time it's fruit production,
dormancy and growth. Appropriate responses are caused by plant hormones. Abscisic acid,
auxins, cytokinins, ethylene and gibberellins all play a role in the development and
survival of a plant. These hormones work in tandem with varying levels within the plant
cells to direct cellular growth, elongation and storage of nutrients and sugars.
Environmental stimuli include light/dark cycles, gravity and touch. A plant that is
germinating will respond with a combination of gravity and light to direct correct
positioning of the stem and root cell growth and a plant that grows tendrils will curl around
structures as the cells come in contact. The hormones auxin and cytokinins work together
for one or both of these responses and cause either an elongation of cells or a suppression
of cell growth. The result visually is a bending or straightening of the plant stem or root.
Branching is another growth affected by the levels of auxin and cytokinins, with each either
stimulating or suppressing branching. At the apical meristem, auxin is abundant and will
suppress budding of branches. As the plant grows, auxin levels are reduced in the cells and
cytokinin hormones increase. Branching occurs with the correct ratio of auxin and
cytokinins and the result can give distinct structural shapes, such as the classic “Christmas”
tree triangle.
In lab today we will be studying the effect of hormones on plant growth and development.
Several examples of plants displaying plant hormone response to environmental stimuli will
be available. You have likely witnessed plant structures and growth in your general
environment. Examples include roots growing out of stem clippings, bending of houseplants
towards a light source and multiple branching after the “tip” of a plant has been pinched.
Objectives
1. Observe and study thigmotropism, gravitropism and phototropism. Identify which
hormones cause response and determine where it exists.
2. Determine apical meristem position and branching affected.
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Gravitropism, Phototropism and Thigmotropism
An example of each plant response is provided in lab. A control set is provided for
comparison. A set was placed in the dark and a set on its side. Another example came from
a garden showing tendrils. Answer the following questions.
Questions
a. Which set displays gravitropism? What hormones are involved?
b. Where would the levels of auxin be the greatest?
c. How do plants sense gravity?
d. Is auxin present in the control set? Why do you not see bending? What is
responsible for the “straight” growth?
e. What hormone stimulates and regulates germination and dormancy? Is this
hormone present in all sets?
f.
What does the set that has been in the dark look like? Do the stems seem long and
stringy? If there was a small light source what would the stems do?
g. What example displays thigmotropism? What is the benefit for this and what
hormones are involved? How would you as a scientist suppress this response?
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Apical Meristems
Note the branching of the example in class. Draw what would happen if the branch tip was
cut.
Questions
a. What hormones are suppressing branching?
b. If you cut the top off a Christmas tree what shape would occur over time?
Explore Further
Questions
a. If ethylene is applied to produce what occurs in the fruits? How would this be
beneficial? How are gibberellins used commercially?
b. Are hormones used in protection of the plant? How?
c. What are phytochromes? How does this affect flowering of plants?
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