Category: 2nd Semester

Caught Red-Handed

 

Caught Red-Handed  

 

Introduction:

Bacteria are everywhere. They have evolved the ability to inhabit almost every surface on the planet; however, they are invisible to the naked eye due to their small size. Bacteria have been found living in the deepest part of the ocean, in volcanic vents, in boiling hot springs, and even deep in polar ice caps. Many species of bacteria live inside of other organisms in a harmless commensalistic way such as the intestinal bacteria, Escherichia coli. Bacteria can reproduce at very rapid rates whenever conditions are favorable, as often as every 20 minutes doubling in number. The bacterial population is kept in check by the natural defenses of the host, such as the immune system and proper washing habits. When these natural defenses fail, bacteria can quickly become a problem. Some bacteria produce poisons or toxins that can be life-threatening if the bacterial population isn’t controlled by our natural defenses.

The United States Centers for Disease Control (CDC) states that the best way to prevent bacterial spread and infection is through the use of proper sanitary techniques. Perhaps the most critical step in this prevention is the use of proper hand washing. When improperly washed, your hands are one of the most easily colonized areas of your body and many of our behaviors involve the use of our hands.  Proper hand washing requires the use of water as hot as you can stand, soap, and lots of rubbing. The soap and water serve to destroy bacteria, and the rubbing helps slough off dead skin cells along with lots of bacteria.

Objective:

Students will examine:

  1. The spread of bacteria through surface contact
  2. Surface washing techniques to reduce the spread of bacteria

Materials (Part A):

Black light, Glo-Germ powder, lotion or Glo-Germ oil, hand soap, water, paper towels, pencil, lab sheet

Procedure (Part A):

  1. Choose one student in the lab group and have them spread a SMALL AMOUNT of Glo-Germ powder or lotion evenly over the entire surface of their hands. Be sure to include hard to clean areas such as around & under the fingernail.
  2. Have another student use the Black light to check your hands for the fluorescent “germs”.
  3. Estimate the percentage of your hand that you have covered with Glo-Germ powder and record this percentage in your data table 1 under time “0”.
  4. Wash your hands for 10 seconds and then recheck your hands with Black light and record the percentage of “germs” remaining.
  5. Repeat step 5 for washing times of 30 seconds, 60 seconds, and 120 seconds.
  6. Return Glo-Germ powder, lotion, or oil to lab cart. 

Data Table 1

 

Time of Wash in Seconds Percent of Hand Covered with “germs”
0 (initial observation)
10
30
60
120

 

Materials (Part B):

Tennis ball, “play” money, stuffed toy, pencil, lab sheet

Procedure (Part B):

  1. Choose a different member of your lab group and use the Black light to check their hands for the presence of germs.  IF they are “infected”, have them thoroughly wash their hands to remove the “germs”.
  2. Record the percentage of their hand that is covered with “germs”.
  3. Pick up the basket from the lab cart with your materials for part B.
  4. Handle the tennis ball for at least 20 to 30 seconds.
  5. After handling the tennis ball, have your hands rechecked with the Black light for “germs”.
  6. Record this percentage in data table 2.
  7. Return to your lab table and handle each of the other items ONE AT A TIME, checking for “germs after EACH item and recording this percentage in table 2.
  8. Return the black light and basket with handled items to the lab cart.

Data Table 2

 

Name of Item Percent Coverage
Initial Hand Coverage
Tennis Ball
“Play” money
Toy

 

Questions:

  1. If almost every surface we touch is inhabited by bacteria, why don’t bacterial infections occur more often?
  2. Name 3 ways you  might prevent the spread of bacteria each day.
  3. Name several bacterial diseases.
  4. Name and describe the 3 shapes of bacteria.
  5. Are all bacteria harmful? Explain your answer.
  6. What effect, if any, did increased washing time have on the percentage of “germ” coverage on your hands?
  7. Name 3 areas of your home that are most susceptible to bacterial contamination. Explain steps you could take in each of these areas to prevent the spread of bacteria to other places in your home.

Optional:

Create a graph based on the data from table 1.

Title _____________________________

 

Bird

 

Birds
All Materials © Cmassengale  

 

 

Birds:

Well adapted to marine, freshwater, & terrestrial habitats
Bodies adapted for flight
Endothermic – body temperature controlled by metabolism

Evolution:

  • Evolved from reptiles
  • Few fossils due to lack of preservation of feathers or thin, hollow bones
  • Archaeopteryx:
    1. Possible link between birds & reptiles
    2. Lived during Jurassic period
    3. Large skull with reptile like teeth
    4. Bones not hollow
    5. Claws on forelimbs
    6. Long tail
    7. Strong legs & rounded wings for gliding
    8. Feathers
    9. Furculum – fused collarbone or wishbone

Archaeopteryx
Archaeopteryx Fossil

  • Hesperonis:
    1. Bird fossils from Cretaceous period
    2. Large, flightless bird
    3. Had teeth like reptiles

kish-02.jpg (71663 bytes)
Hesperonis

  • Ichthyornis:
    1. Smaller, tern like bird
    2. Lived during Cretaceous period
    3. Had large flight wings

 

Section 1 Review

 

Characteristics of Birds:

  • Body covered with feathers made of protein called keratin
  • Thin, hollow bones
  • Some bones fused for extra strength
  • Forelimbs modified into wings for  flight
  • Two hind limbs with claws to support upright body
  • Scales on legs
  • Toothless, horny beak
  • Additional air sacs  with lungs for more oxygen
  • Endotherms (40 to 41 degrees Celsius body temperature)
  • Four chambered heart with single, right aortic arch
  • Amniote egg with calcium carbonate shell
  • Oviparity with both parents often caring for eggs
  • Eggs usually incubated within a nest

Feathers:

  • Modified scales
  • Function to provide lift for flight & help conserve body heat
  • Five kinds of feathers —– down, contour, flight, filoplume, & bristles


Types of Feathers

  • Down feathers:
    1. Soft & fluffy
    2. Cover the body of nestlings
    3. Provide an undercoat insulating adult birds
  • Contour Feathers:
    1. Give streamline shape to body
    2. Provide coloration to adult birds
    3. Give additional insulation to body
  • Flight Feathers:
    1. Specialized contour feathers
    2. Found on wings & tail

  • Filoplumes:
    1. Called pin feathers
    2. Hairlike feathers under contour feathers on body

Parts of a feather:

  • Develop from tiny pits in the skin called follicles
  • Shaft emerges from the follicle
  • Two vanes develop on either side of shaft
  • Barbs branch off of each vane & have projections called barbules
  • Barbules have microscopic hooks to hold barbules together


Parts of a Flight Feather


Microscopic Hooks on Barbules

  • Birds preen their feathers to clean them & coat them with oil
  • Preen glands – oil glands located at the base of the tail
  • Birds shed or molt feathers periodically:
    1. Molting usually in late summer between breeding & migration
    2. Flight feathers replaced
    3. Some birds molt before courtship

Beaks and Feet:

  • Adapted to habitat & feeding
  • Hawks & eagles have hooked beaks & talons for tearing meat

 

Gentoo Penguin
Talons Hooked Beak Penguin Flippers

 

  • Swifts have tiny beaks that open wide to catch insects in midair
  • Flightless birds like ostriches have legs & feet modified for running & walking
  • Penguins have wings modified into flippers for swimming
  • Ducks & geese with webbed feet

 

Running Legs of Ostrich Webbed Feet on Duck

 

  • Legs of some birds such as herons &  egrets turn vivid colors to attract mates; caused by hormones

Skeleton and Muscles:

  • Pelvic & pectoral girdles fused for strength
  • Bones thin & hollow so bird lighter

A birdbone(notice the honey combed shape)
Hollow Bones

  • Furculum or wishbone is a fused collarbone that stabilizes bird in flight
  • Lighter beak replaces heavy teeth & jaws
  • Lower vertebrae fused so no heavy ligaments needed
  • Enlarged eye sockets reduce skull weight
  • Keeled sternum for attachment of large flight muscles
  • Pygostyle – terminal vertebrae support tail & aids in flight (lift, steering, & braking)
  • Two digits in forelimbs lost & other three digits fused to form wings
  • Wings shaped like air foils (thicker in front & tapering to back) so air moves faster on top causing lift

  • Powerful muscles make up 50% of body weight
  • each wing movement uses different set of muscles
  • Flight muscles called pectorals & are attached to wing & keeled sternum
  • When large pectorals contract, wings move down
  • When large pectorals relax & small pectorals contract, wings move upward

Body Temperature:

  • Metabolism generates body heat (endothermic)
  • Enables birds to survive in warm & cold environments
  • Rapid breathing & increased air sacs in lungs bring in more oxygen

Diagram of a bird's lung and air sac system, and countercurrent exchange
Air Sacs in Bird Lungs

  • Ingest large amounts of food for energy
  • Fluff out feathers to trap air for insulation
  • Aquatic birds have thin layer of fat for insulation

Digestive System:

  • Fast & efficient digestion (mouse digested in 3 hours)
  • No chewing
  • Crop for temporary food storage
  • Two part stomach — proventriculus & gizzard
  • Proventriculus is 1st chamber where digestive juices added
  • Gizzard is 2nd part for crushing food
  • Small stones & gravel eaten by birds aids grinding in gizzard
  • Pyloric sphincter valve at lower end of gizzard controls food movement into intestines
  • Duodenum – beginning of small intestine where bile (digests fats) & pancreatic juice are added & digested food is absorbed

birdanat.gif (87464 bytes)

Excretory System:

  • Paired kidneys filter nitrogen wastes (uric acid) from blood
  • No urinary bladder to store liquid wastes
  • Uric acid travels down ureters to cloaca where intestinal wastes & reproductive products added
  • Uric acid secreted in white, semi solid mass
  • Shorebirds have salt secreting glands above the eyes & secrete excess salt through their nostrils

Respiratory System:

  • Fly at high altitudes where there is less oxygen so need efficient respiratory system
  • High metabolic rate requires large amount of oxygen
  • Nine air sacs associated with lungs increase oxygen level & decrease density
  • Air sacs connected to air spaces in hollow bones
  • One way flow of air in lungs & air sacs so more oxygen is removed
  • Air pathway:
    air enters body through nostrils on beak  trachea (windpipe) syrinx (voice box) 2 primary bronchi 75% of air into two posterior air sacs and 25% of air into lungs air from lungs into other seven air sacs
  • When carbon dioxide exhaled, oxygen from posterior air sacs moves into lungs to always keep fresh oxygen supply

Circulatory System:

  • Four chambered heart
  • Right side of heart pumps deoxygenated blood from body cells to lungs
  • Left side of heart receives oxygenated blood from lungs & pumps it to the body cells
  • Single aortic arch
  • Rapid heartbeat (hummingbird 600X/minute & chickadee 1000X/minute)
  • Less active birds such as ostrich have slower heart rates (70X/minute)

Nervous System:

  • Large brains relative to size of bird
  • Most highly developed brain areas control flight
  • Cerebellum coordinates movement
  • Cerebrum controls navigation, mating, nest building, & care of young
  • Optic lobes receive & interpret visual stimuli
  • Keen vision
  • Have color vision for locating food
  • Large eyes located on side of head for wide field of vision in most birds
  • Some birds such as owls with eyes on front of head for binocular vision (depth perception)
  • No external ears, but have feathers around ear openings to direct sounds into ear canals
  • Tympanic membrane or eardrum for picking up sound vibrations
  • Semicircular canals in inner ear regulate balance
  • Poorly developed sense of smell except in ducks & flightless birds
  • Sense of taste helps avoid bitter tasting or toxic foods

Reproductive System:

  • Testes in males produces sperm that travels by the vas deferens to cloaca
  • Females have single ovary that makes eggs
  • Eggs are fertilized in the oviducts
  • Shell added by shell gland & then egg moves into
  • In mating, male presses cloaca to female to transfer sperm (internal fertilization)
  • Lay an amniote egg:
    1. Embryo suspended in fluid called albumen (white of egg)
    2. Chalaza – rope like strands suspending embryo in albumen
    3. Chorion is membrane inside of shell
    4. Yolk is stored food surrounded by yolk sac


Bird Egg

Incubation & development of Egg:

  • Eggs incubated by one or both parents
  • Brood patch – thickened, featherless patch of skin on abdomen of bird used to warm eggs
  • Membranes grow out of embryo’s digestive tract & surround yolk
  • Membranes make digestive enzymes to dissolve proteins & lipids in yolk
  • Yolk sac has blood vessels to carry food to embryo
  •  Wastes from embryo collect in membrane called allantois
  • Chorion membrane lines the shell & allows gas exchange
  • Young birds may be precocial or altricial
  • Precocial young:
    1. Have longer incubations
    2. More eggs laid
    3. Active as soon as hatch
    4. Nestlings can swim, walk, & feed themselves
    5. Need some parental care
    6. Includes ducks, geese, & swans
  • Altricial young:
    1.Lay fewer eggs
    2. Hatch quickly
    3. Hatchlings are blind, naked, & helpless
    4. Depend on parents for warmth & food for several weeks
    5. Includes songbirds, woodpeckers, hawks, pigeons, doves, raptors

 

Dunnock & Cuckoo
Altricial Young Precocial Young

 

Behavior:

  • Longer parental care allows more complex learning (courtship, nesting, migration, etc.)
  • Territoriality allows males to establish & defend breeding areas
  • Courtship behaviors are used by males to attract mates:
    1. Brightly colored feathers
    2. Flight displays
    3. Songs


Male Scarlet Tanager Breeding Plumage

  • Nest building holds eggs, conceals & shelters young birds, may help attract mates
  • Nests are built in sheltered, well-hidden spots in trees, on the ground, etc. & are made of twigs, mud, grass, feathers…

  • Migration to new areas is triggered by dropping temperatures & dwindling food supplies
  • Birds use migration clues including:
    1. Position of sun & stars
    2. Topographical landmarks
    3. Magnetic clues
    4.Air pressure changes
    5. Low frequency sounds

 

Section 2 Review

Classification:

  • Class Aves
  • 27 orders
  • Gaviiformes – loons
  • Pelecaniformes – pelicans & cormorants
  • Ciconiiformes – wading birds like ibises & herons
  • Anseriformes – ducks, geese, & swans
  • Falconiformes – falcons, eagles, hawks, vultures
  • Galliformes – turkey, quail, pheasants
  • Gruiformes – cranes, coots, & rails
  • Charadriiformes – snipes, sandpipers, gulls, terns
  • Columbiformes – pigeons & doves
  • Psittaciformes – parrots, parakeets, & macaws
  • Cucluiformes – cuckoos & roadrunners
  • Strigiformes – owls
  • Caprimulgiformes – whippoorwill & nighthawk
  • Apodiformes – hummingbird & swifts
  • Coraciiformes – kingfishers
  • Piciformes – woodpeckers, sapsuckers, & flickers
  • Passeriformes – perching birds like robins, cardinals, blue jays

 

Pelican at Oranjestad waterfront
Pygmy Owl Brown Pelican
photograph of macaw Female Northern Cardinal Photograph
Macaw Female Cardinal

 

Food & Habitat Adaptations:

  • Anseriformes (ducks, geese, & swans) have webbed feet for swimming & flattened bills; young are precocial but need some parental care
  • Strigiformes (owls) have sharp, hooked beaks & talons (claws) for meat eating, keen hearing & eyesight, & forward facing eyes
  • Apodiformes (hummingbirds) are small, fast-flying birds with tiny feet & long tongues for drinking nectar; found only in western hemisphere
  • Psittaciformes (parrots, cockatoos, parakeets…) have a strong, hooked beak for seed opening & two forward & two rear facing toes for perching & climbing
  • Piciformes (woodpeckers, toucans, & flickers) have two rear facing toes for dwelling in tree cavities & sharp, chisel like bills for drilling into trees
  • Falconiformes or raptors ( hawks, eagles, vultures) have hooked beaks & talons & keen vision for seeing prey
  • Passeriformes or songbirds (blue jays, cardinals, sparrows, robins …) have enlarged rear facing toe to grip branches, a syrinx or voice box in males to produce songs, & a variety of beak shapes to feed on seeds, nectar, fruits, & insects; known as passerines or perching birds
  • Columbiformes (pigeons & doves) have small heads & bills, a crop that makes “pigeon’s milk” for feeding young, short incubation period (2 weeks)
  •  Ciconiiformes (herons, ibises, & egrets) have long legs for wading & sharp pointed bills for piercing frogs & fish
  • Galliformes (turkeys, quail, pheasants, & chickens)  have plump bodies with limited flying &a large gizzard for grinding grains
  • Sphenisciformes (penguins) have wings modified into flippers, an extra layer of body fat for insulation, & webbed feet for swimming
  • Struthioniformes (ostrich) are the largest birds that can’t fly but have long legs with only two toes adapted for fast running
Section 3 Review

 

BACK

 

Build a Bug

 

Build-a-Bug

 

Introduction:

Most adult insects have the following characteristics:

    1. A body divided into three parts (head, thorax and abdomen)
    2. Three pairs of legs
    3. Usually one pair of antennae and a pair of compound eyes (a few exceptions to these characteristics are found)
    4. Usually two pairs of wings (absent in many insects such as lice, fleas, ants; flies have one pair of wings)

There are approximately 30 orders of insects. Choose one of the insects from these orders.

INSECT ORDERS

Click on the link to learn more about the characteristics of that order. There are links to specific insects on each page.  Visit the Field Guide Index to see a listing of all insects featured in the Field Guide.

Objective:

Students will build biologically correct insects in order to learn insect structure and adaptations.

Materials:

Any non-food item such as cardboard, egg cartons, clay, wire, felt, Styrofoam, pipe cleaners, nylon stockings, pipe cleaners, paint, glue, string, etc.

Guidelines:

  1. Your model must be an INSECT (i.e. no spiders, mites, ticks, centipedes, or millipedes, please). Note: Your insect does not have to live in the United States.
  2. Your model must be between 6-12 inches long, and sturdy.
  3. Be accurate when building your model (appropriate proportions, true color and form, etc.).
  4. The more detail your model has, the better.
  5. A written description must accompany your model and include:
  • The common name of the insect
  • The name of the order to which it belongs
  • A brief description of the insect’s habitat
  • Where the insect is located geographically
  • At least 2 interesting, and unique facts about the insect you have modeled (i.e. “it has 6 legs and 3 body segments” doesn’t count)
  • Your name and address on model description

Examples of Models:

 

 

Spiny Katydid Monarch
Dragonfly Damselfly Luna Moth
Walking Stick Grasshopper Yellow jacket
Atlas Moth Carpenter ant Praying Mantid