8/2/2019 Flower Dissection Lab Spring 2011

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La Guardia Arts Science Spring 2011

Name:____________________________________________ Lab # ________ Period: _______

The Fantastic & Fabulous Flower Dissection LabIn this lab, we will examine and study Angiosperms which are seed-bearing plants that produce fruits and

flowers to aid in sexual reproduction. All flowers can vary in the number and type of the parts and characteristics

including: color, shape, size and smell. These features are what can attract specific insects to the plants to aid in thepollination process.

Flower structures can be divided into two groups: the essential organs and the accessory organs. The essential

organs of the plants reproductive structures are the male stamen and the female pistil. The accessory floral organs

include petals and sepals that can assist in the process of sexual reproduction but are not necessary for reproduction to

occur.

In order for plants to reproduce sexually, the male and female gametes must meet and fuse. The sperm nuclei

are in the pollen grain and the egg nuclei are in the ovules. For them to meet and fertilization to occur, the pollen grain

must be transferred (via pollination) from an anther of a stamen to the sticky stigma of a pistil. If this occurs, a pollen

tube forms to allow the sperm nuclei to enter the ovule and fertilize the egg. After fertilization, the ovule turns in the

seed. The ovary develops into the fruit and contains all of the developing seeds (ovules).

Materials:Flowers Hand Lens (Magnifying Glass) Scalpel or Razor Microscope Setups (already prepared)

Objectives: Today in this flower dissection lab, you and your group members will:

1) Draw and label your flower

2) Count the amount of each plant part your flower has and record the values in a data table

3) Observe and illustrate the essential and accessory organs of your flower using a magnifying glass and prepared

microscope slides

4) Evaluate the characteristics of flowering plants that help aid in pollination and fertilization

Part I: Flower Power: Getting to know your flower

1. Common name of your flower: _____________________________________

2. Scientific name of your flower: _____________________________________

3. Draw and Label Your Flower: (note: only draw what you can see)

Example Sketch Your Sketch

Part II: Counting Parts!Using your magnifying glass for assistance if necessary:

1. Count and record (in data table A) how many of each of these parts your flower has:

Data Table A:

Plant Part Name: Amount Your Plant Has:

Sepals (thick outer parts that protect flower when it is closed)

Petals (Colorful parts of flower that help attract pollinators)

Stamens (Male reproductive structure made up of anther and filament)

Pistils ( Female reproductive structure- made of stigma, style, ovary andovules)

Ovules (eggs, inside the ovary)you will count these in Part III

8/2/2019 Flower Dissection Lab Spring 2011

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La Guardia Arts Science Spring 2011

2. Describe the color and smell of your flower: ________________________________________

______________________________________________________________________________

______________________________________________________________________________

Part III: Up Close & Personal:

1. Carefully isolate the pistil of your flower and cut the ovary vertically at its widest region.a) Examine the ovary under the magnifying glass.b) Diagram and label the cross-section of the ovary belowc) How many ovules do you count? (Record in Data Table A)

2. Go up to the front of the lab and examine the prepare slide of pollen grains.a) Can you make an estimate of how many pollen grains you see?

b) Sketch what you see under the microscope in the box below:

Analysis Questions:1) What is the advantage of plants having colored petals?

2) Give two examples of ways in which pollen can travel from one flower to another for pollination?

3) How is pollination different from fertilization?

4) Does your flower produce more ovules than pollen grains or vice versa? In terms of reproductive success,

why would this be important?

5) Pollen grains are the male sex cells of the flower. Eggs are the female sex cells. When the pollen is

brought to the female part of the flower it is called pollination. Why do you think that the pistil is sticky at

the top?

6) An apple tree is an example of an angiosperm. In this particular example, what does the ovary of the apple

tree flower turn into?; What do/does the ovule(s) turn into?