FLOWERS AND POLLINATION
This activity introduces the relationship between flower structures and pollination.
Objectives for Exam #1:
1. Identify flower structures and match those structures to specific functions.
2. Contrast characteristics of flowers pollinated by wind with those pollinated by animals.
3. Describe the classification, life cycle, and significance of honey bees.
Objective for Portfolio #1:
Draw and label a flower, and a microscopic view of pollen.
Part I: Flower Stations:
Station A: Flower Anatomy
1. From the “Flowers” poster, the “male” part of a flower is the stamen. The anther holds the
pollen and the _________________ holds up the anther so the pollen is exposed to a
pollinator. The “female” part of a flower is called the __________________ (or “carpel”).
The stigma is the flower part that receives the ________________. Attached to the stigma
is the ________________, a tube-like structure that connects to the ovary. Inside the ovary
are ___________, which are female reproductive cells like “small eggs.” So ovules in the
ovary are equivalent to eggs in human females, and the pollen is the equivalent to
____________ in human males.
2.
The corolla of the flower is a group of _________________ that attract a pollinator. The
calyx is a group of __________________ that covered and protected the bud before the
flower opened.
3. Label the location of the pistil and stamen on the flower photo below:
** Go to page 19 and complete the portfolio flower sketch.
4. Pollen are structures with a hard coating protecting sperm cells. Pollen travels to the
female reproductive structures of a flower. From the Pollen and Spores poster, how do the
flower pollen grains differ from the fungal spores of Aspergillis and Penicillum? (hint: look at
the magnifications) ________________________________________________________
5. Examine the pollen slide under the microscope. Using the pollen guide for assistance, what
type of pollen do you see? ____________________________________
** Go to page 19 and complete the portfolio pollen sketch.
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Station B: Floral Diversity
1. Referring to the Floral Diversity poster, provide examples of flowers for each of the following
flower types:
Flower
Type
Description
Imperfect
Individual flowers lack either the male (stamen) or
female (carpal) flower parts
Complete
Flowers have sepals (structures that protect the
bud), petals, stamens, and carpals
Composite
The “flower” we see is actually a combination of
many flowers forming a single round head. The
flowers may have different shapes.
Spadix
The spike in the middle is covered in small flowers,
with one huge petal-like structure
Catkin
A structure made of many petal-less imperfect
flowers (so there are “male” and “female” catkins)
Example Flower
2. By the poster is a “sample” flower. Using the chart above, what is its flower type?
______________________________
Station C: Animal Pollination
Most species of flowering plants sexually reproduce with the assistance of animals, the
pollinators (primarily insects, birds, and bats), that carry pollen. Plants pollinated by pollinators
typically expend less energy on pollen production than wind-pollinated plants. These plants
have flowers with specific shapes, textures, colors, patterns, odors, and/or food rewards that
can attract unique pollinators (or their prey).
1.
From the display, fill in the flower type that attracts each of the following pollinators and an
example plant:
Pollinator
Flower Characteristics
Bee
Fly
Butterfly
Night-feeding
Moth
Bat
Beetle
Hummingbird
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Plant Example
2. Thought Question: In some large, showy flowers, the “flower” as we think of it is actually an
arrangement of many smaller flowers. For example, a sunflower “flower” is actually a
composite of many smaller flowers. From the plant’s perspective, what is the advantage of
having this structure made up of many smaller flowers?
3. Thought Question: Carl Linnaeus (1707-1778) observed that certain plants opened and
closed their flowers at specific times of day. He proposed that a “flower clock” garden could
be planted to indicate the time of day. Gardeners plant regional flower clocks around the
world today. Considering that most flowers rely on animal pollinators for reproduction, what
could be an advantage to a plant of flowering at a specific time of day that differs from the
flowering time of other plants?
Station D: Bees
Order Hymenoptera
1. Bees, wasps, and ants are classified in Order Hymenoptera (Orders will be covered in class
next week) and share common physical features, most typically a membranous wing. Many
also have venomous stingers used for defense or immobilizing prey. How do bees, wasps,
and ants differ?
Hymenopteran
Characteristics
Bee
Wasp
Ant
2. Paper wasps and some hornet species can build a large nest out of paper made from
chewed-up plant material. Magnifying a piece of a paper wasp nest, what does it look like?
______________________________________________________________
Honey Bee Life Cycle
3. Using the honey bee models, label the photo below with the life cycle stages and bee
products:
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Bee Flower
4. Insects see fewer colors in the “visible” spectrum of than humans (some species can’t see
red), but many can sense ultraviolet light (different wavelengths). Some flowers have
ultraviolet markings called nectar guides that humans can’t see without special cameras.
From the display, list two types of flowers that have ultraviolet nectar guides:
__________________________ and __________________________
Bee Mimic
5. From the Willamette Valley card, what is an insect that has structures and colors that mimic
a bee? __________________________ What do these insects actually eat?
______________________________ How can mimicking a bee be an advantage?
Station E: Wind Pollination
1. Wind-pollinated plants produce large amounts of pollen, and some of the pollen makes it to
another flower for successful pollination. Wind-pollinated flowers are typically green, small,
odorless, and do not produce nectar, as they do not need to attract pollinators. In the
bottom right of the Floral Diversity poster are the grass plants, which are ___________ pollinated.
2. Below are photos of two models: a wheat flower and a rye flower. Label the following on
these flowers: the anthers (produce pollen) and stigma (receives pollen)
3. In a corn plant, a cluster of male flowers is called a tassel. The male flowers produce
____________ which is carried by the wind to female flowers. Pollen falls onto the silks of
female flowers, which develop into individual corn kernels. Typically the male and female
flowers on a single plant mature at different times, to prevent self-pollination. Label the
parts of a corn plant indicated by arrows on the picture below.
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Station F: Preserved Flowers
1. Thought Question: Botanists (biologists who study plants) often work with preserved flower
specimens that are dried, frozen, or stored in alcohol. Herbariums (collections of preserved
plant specimens) typically consist of pages of dried plants that were prepared using
specialized plant presses. You can also press thin flowers, leaves, stems and roots using a
book. Place the sample between two sheets of blank paper amid the pages of a book.
Weigh the book down and wait a few weeks. Looking at the preserved specimens, what is
an advantage and a disadvantage of studying preserved flower specimens (or leaves, as in
the portfolio assignment) instead of relying on live specimens?
2. Flower features can assist you in identifying a species. These features include: the height of
the flower from the ground; the number of petals (mustards have four, asters have many);
the shape of the flower (tube, flat); colors and patterns (stripes, dots, spots, zones); and
the sepals (longer or shorter than the petals). Using the wildflowers display, identify the
pressed flower: _________________________________
3. Scan the Willamette Valley flower cards, which of these plants is potentially edible?
_________________________________________________________________ Which is
potentially toxic to humans? _________________________________________
(As always in the field, accurate identification is essential before eating any wild organism).
Part II: Labeled Flower and Pollen Drawings (for Portfolio #1, stamp required)
Skill: Draw and label a flower, and a microscopic view of pollen.
Assignment: On the following page: 1. Sketch a “live” flower, recording the name of the
flowering plant, and labeling your sketch with the following: pistil (stigma, style, and ovary),
stamen (anther and filament), petal, and sepal. 2. Sketch a pollen specimen viewed under the
microscope, including the name of the flowering plant the pollen came from and the
magnification of the pollen. Have your GTA stamp the page before leaving. The stamp does
not indicate that the assignment is correct; it is a record that you completed the drawings in
class.
Assessment: This assignment project is worth 2.0 points: 1.25 points for the labeled flower
(0.25 pt. for flower name, and 1.0 point for sketch and four labels of pistil, stamen, petal, and
sepal) and 0.75 point for the pollen sketch (0.25 pt. for the plant the pollen came from, 0.25 pt.
for magnification, 0.25 pt. for pollen sketch). The drawings need to be completed and stamped
in the Flowers activity or during GTA office hours weeks 1 (no later) to receive credit for this
assignment.
Important: Portfolio assignments represent your individual skills. Do not submit an assignment
that is a duplication of any other individual’s assignment. Information on academic honesty is
available in the course syllabus and at the course website. If you have any questions regarding
your work, please ask before submitting your portfolio.
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Flower and Pollen Labeled Sketches
(Include this stamped page in Portfolio #1)
Type of flower: _____________________________________________
Draw and label in the box below: pistil (stigma, style, and ovary),
stamen (anther and filament), petal, and sepal.
Pollen specimen is from a __________________________ flower.
Magnification = ________x (magnification of eyepiece x objective)
Sketch the pollen in the circle below, no labels required on drawing.
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STAMP
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