ZachMarilinSophiaVictor AlexChris Gaby Julian AnnahiDaisyCrystalCarlos Ashley Brennan DylanEsme...
-
Upload
garey-russell -
Category
Documents
-
view
214 -
download
0
Transcript of ZachMarilinSophiaVictor AlexChris Gaby Julian AnnahiDaisyCrystalCarlos Ashley Brennan DylanEsme...
Zach Marilin Sophia Victor
Alex Chris Gaby Julian
Annahi Daisy Crystal Carlos
Ashley Brennan Dylan Esme
Jordyn Jacob Jas Hannah
Riley Odom Selena
Scotty Luis Jeska Jesica
DOOR
MR. CATER’S DESK
DISCUSS WITH L.P.
A woman was shown into a large room which contained over a thousand flowers. She was told that all but one of the flowers were artificial. She had to identify the real flower, but she could not examine the flowers closely nor smell them. She was alone in the room. What did she do to identify the single flower?Clues: She got some help.No other person was involved.
signal
• After you hear the bell, you have 5 seconds to…
… achieve silence… look me in the eyes… remain silent until I give
instructions
R.E.A.C.T.
R espect everyoneE nter and exit appropriatelyA ccept responsibilityC ooperate with everyoneT ake action
YouTube Video pollen from trees making...me...sneeze!!!http://www.youtube.com/watch?v=SiC0k4KtP9g
As you watch the video, think about:
1)Why is this guy sneezing?2)Why is Mr. Cater showing us this
video in our Forensic Science class?
ALLERGIESWhen I was at UT, one of my
biology professors defined an allergy as…
“An inappropriate immune response”
Turn to your learning partner and discuss the meaning of that statement:
“An inappropriate immune response”
Each person will need:
1 index card
1 pair of scissors
1 piece of packing tape
1 piece of string
Obtain your materials
Cut a large rectangle out of the index card, leaving just the outside edges.
Make sure the edges are still large enough to write on.
STEP 1
Stop and write- How much pollen do you expect to catch?- How should we analyze the pollen? What
instruments or techniques should we use?- How do you think pollen collected here
differs from pollen in El Paso? - How would pollen collected in the fall differ
from pollen collected in the spring?
Pollen fingerprint: 4 essential parts
1 number of pollen grains2 type of pollen grains3 found in a certain area4
Pollen fingerprint: 4 essential parts
1 number of pollen grains2 type of pollen grains3 found in a certain area4 at a particular time of year
Pollen fingerprint: Who cares?
Forensic playnologists, because a pollen fingerprint can link a piece of evidence to a particular place and time.
Forensic Science: Fundamentals & Investigations, Chapter 5
36
DIRECT TEACH – TAKE NOTES
• Distinguish between pollen and spores• Define a pollen fingerprint • Classify the different organisms that produce pollen and
spores • Compare and contrast the female and male reproductive
parts in plants • Distinguish between gymnosperms and angiosperms
All Rights Reserved South-Western / Cengage Learning © 2012, 2009
Forensic Science: Fundamentals & Investigations, Chapter 5
37
More learning objectives
• Summarize the different methods of pollination and their relevance in solving crimes
• Identify the different ways spores are dispersed • State characteristics of pollen and spores that are important
for forensic studies • Summarize how pollen and spore evidence is collected at a
crime scene • Describe how pollen and spore samples are analyzed and
evaluated
Forensic Science: Fundamentals & Investigations, Chapter 5
38
IntroductionIntroduction
Forensic palynology—a specialized field that studies pollen and spore evidence
• Pollen and spores are microscopic reproductive structure that have resistant structures
• Pollen—contains the male gametes of seed plants
• Spores—found in certain protists, algae, plants and fungi
Abstract Part 1Two male intruders entered a house in which the sole
female occupant slept having left the back door unlocked for the return of her live-in boyfriend. She awoke and saw strangers in her bedroom. The intruders ran off, one leaving a jacket behind on the kitchen floor. One of the intruders subsequently returned to recover his jacket, but in his rush to leave the house he brushed against a flowering Hypericum bush growing just outside the back door. A suspect was arrested later that day and charged with indecent assault on a female and burglary, but denied any involvement and refused to name any associate.
Abstract Part 2
A day following the offence the suspect's clothes were taken for forensic examination. Pollen analysis of selected parts of his clothing showed that his track pants contained 14% Hypericum pollen, denim jacket 24%, and polo shirt 27.5%. Traces of Hypericum pollen occurred on other items. Most of these pollen grains still had their cell contents preserved and were on the clothing in clumps consistent with having recently been collected by the clothing and not having been aerially dispersed. The pollen from the Hypericum bush was identical in colour, shape, development, and size range to the pollen from the clothing. The clothes had so much Hypericum pollen on them that they had to have been in direct and intimate contact with a flowering bush.
Abstract part 3
Pollen evidence is by its nature circumstantial and often cannot be used on its own to convict, or more strictly to determine the truth. The suspect may have been in contact with Hypericum elsewhere, but detailed investigations indicated that this was unlikely. In 30 years of New Zealand forensic work Hypericum had only ever been found on clothing in trace amounts. This is but one way in which forensic palynology can assist law enforcement agencies to determine the history behind a criminal action, and demonstrates that forensic palynology should be considered as an integral part of any criminal investigation.
Forensic Science: Fundamentals & Investigations, Chapter 5
43
Introduction Introduction
• Pollen and spore analysis entails Locard’s Principle of Exchange
• Pollen and spores can help determine:– whether a body was moved– a crime’s location—in a city or in the country– the season
Forensic Science: Fundamentals & Investigations, Chapter 5
44
Pollen-Producing Plants Pollen-Producing Plants
Pollen fingerprint—the number and type of pollen grains found in a geographic area at a particular time of year
Non-seed plants – SPORES – ferns, mosses, liverworts, and horsetails
Seed plants – POLLEN – gymnosperms (cycads, ginkgoes, and conifers)– angiosperms (flowering plants)
Forensic Science: Fundamentals & Investigations, Chapter 5
45
Gymnosperms Gymnosperms
• Gymnosperms are the oldest seed plants• Conifers are the largest group• Seeds are contained in hard, scaly structures called
cones• The male cones pollinate the female cones• Which cone is female and which is male?
Forensic Science: Fundamentals & Investigations, Chapter 5
46
AngiospermsAngiosperms—Flowering Plants —Flowering Plants
• The most recent plant group to evolve• Produce seeds in an enclosed fruit• Very diverse group
(includes corn, oaks, maples, and the grasses)• Pistil—female part• Stamen—male part• Identify the parts in this
illustration
Forensic Science: Fundamentals & Investigations, Chapter 5
47
AngiospermsAngiosperms—Flowering Plants – —Flowering Plants –
identify these parts on your flower identify these parts on your flower
Is your flower MALE, Is your flower MALE, FEMALE, or BOTH ?FEMALE, or BOTH ?
Forensic Science: Fundamentals & Investigations, Chapter 5
48
Types of Pollination Types of Pollination
• Pollination—the transfer of pollen from the male part of a plant to the female part of a seed plant
• Self-pollination—pollen transfers from an anther to the stigma within the same flower, as in pea plants
• Cross-pollination—pollen transfers between two distinct plants
Forensic Science: Fundamentals & Investigations, Chapter 5
49
Types of Pollination Types of Pollination
Forensic Science: Fundamentals & Investigations, Chapter 5
50
Types of PollinationTypes of Pollination
• Pollen of self-pollinating plants– Rarely encountered– Lower value in forensic studies
• Pollen can be carried by – Wind – Animals – Water
• Wind-born pollen is less effective – Potentially long distances
In your notebook, draw a picture of pollen you observe under the microscope.
Also write a description what the pollen looks like.
Then, compare your drawing/ and description with others.
15 minutes
Forensic Science: Fundamentals & Investigations, Chapter 5
55
Spore Producers Spore Producers
• Spore producers include – Certain protists (algae)– Plants – Fungi – Bacteria
• Bacterial spores, endospores include diseases such as anthrax and botulism
• Spore advantages– Spores can be grown to increase sample size– Identifiable with certainty
Forensic Science: Fundamentals & Investigations, Chapter 5
56
Spore Dispersal Spore Dispersal
• Algae disperse spores into water or air
• Potentially large dispersal range reduces value in investigations
• Explain how mushroom spores are released into the wind
Forensic Science: Fundamentals & Investigations, Chapter 5
57
Pollen and Spore Identification Pollen and Spore Identification in Solving Crimes in Solving Crimes
Exine– Outer shell of a pollen grain and spore– Microscopes reveal complex and unique
structures– Identification provides potential trace
Angiosperm pollen grains
Gymnosperm pollen grains
Forensic Science: Fundamentals & Investigations, Chapter 5
58
Finding Pollen and SporesFinding Pollen and Spores
59
Collecting Pollen and Spores Collecting Pollen and Spores
• Control and evidence samples must be collected
• When collecting samples:– Wear gloves– Use clean tools– Place in sterile containers, sealed and labeled– Secure and establish a chain of custody
• Sampling instruments must be clean or new
Forensic Science: Fundamentals & Investigations, Chapter 5
60
Analyzing Pollen and Analyzing Pollen and Spore Samples Spore Samples
• Pollen and spores are chemically extracted from samples
• Tools specialists use to examine and identify include:– compound light microscope– scanning electronic microscope (SEM)– reference collections
(photos, illustrations, dried specimens)
• Pollen and spore evidence—collected, analyzed, and interpreted—can be presented in court
Forensic Science: Fundamentals & Investigations, Chapter 5
61
. . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary . . . . Summary . . . .
• Forensic palynology can indicate something about the geographic origin and the time or season of a crime.
• Spores and pollen can be dispersed by wind, by water, or by animals.
• Pollen from insect-pollinated plants tends to give more specific location data than from wind-pollinated plants.
Forensic Science: Fundamentals & Investigations, Chapter 5
62
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary Summary
• Pollen collected at a crime scene must include baseline samples from the area for comparison.
• Collection of pollen and spore evidence must be performed carefully to avoid contamination.