Plant Anatomy & Physiology � �Lesson 4��Flower Anatomy

Introduction to Horticulture

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Student Learning Objectives

• Describe the parts of a flower.

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• Explain the purpose of a flower.

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• List some different types of flowers.

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• Describe the difference between monocot and dicot flowers.

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Introduction to Horticulture

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Terms

• anther
• calyx
• complete flower
• corolla
• fertilization
• filament
• imperfect flower
• incomplete flower
• ovary
• perfect flower

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Introduction to Horticulture

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Terms

• petals
• pistil
• pistillate
• pollen
• pollination
• sepals
• stamen
• staminate
• stigma
• style

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Introduction to Horticulture

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Essential Question:

What are the parts of a flower?

Introduction to Horticulture

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What are the parts of a flower?

• Flowers are the most obvious part of most plants.
• They are made of many intricate and important parts.
• Most flowers contain both male and female parts.

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What are the parts of a flower?

• The male part of the flower is called the stamen, which is made of the stalk-like filament that holds up the sack-like anther.
• The anther contains pollen,

the grain released by flowers,

which contains the sperm.

• Flowers that only have

male parts are called staminate.

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What are the parts of a flower?

• The female part of the flower is called the pistil.
• It consists of a sticky tissue at its end called the stigma, which is receptive to pollen.
• Below the stigma is a rod shaped middle part called the style and a swollen base containing eggs called the ovary.
• Flowers that only have female parts are called pistillate.

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What are the parts of a flower?

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The ovary contains the eggs

The anther contains and releases the pollen at maturity

What are the parts of a flower?

• Flowers also often have

parts that are neither

male nor female; these

are the petals, usually

colorful leaf-like structures

that often attract animals

and insects.

• When all of the petals are fused together, we call them a corolla.

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What are the parts of a flower?

• Beneath the petals are

more leaf-like structures,

called sepals, which are

often green. The sepals

support the petals and

protect the flower before

it opens.

• When all of the sepals are fused together, we call them a calyx.

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Essential Question:

What is the purpose of a flower?

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What is the purpose of a flower?

• The purpose of a flower is for a plant to be able to reproduce sexually.
• The process of sexual reproduction in plants follows.
• The first step in sexual reproduction is for the stamen to release its pollen.
• The pollen is carried by animal,

wind, gravity, or many other

methods to the stigma of another

flower.

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What is the purpose of a flower?

• When the pollen from one

flower lands on the stigma

of a compatible flower, we

call it pollination.

• Flowers are adapted to

pollinate each other in an

astounding number of different

ways using an equally amazing

number of methods, called

vectors, to help them.

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What is the purpose of a flower?

• Once the pollen reaches the stigma,

it starts to go down into the style,

depositing sperm in the ovary.

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What is the purpose of a flower?

• When the sperm combines with the

eggs in the ovary, we call it

fertilization.

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What is the purpose of a flower?

• After the eggs have been

fertilized, the ovary and

surrounding tissue start to

enlarge to become a fruit and

the fertilized eggs become seeds.

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Essential Question:

What are some different types of flowers?

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What are some different �types of flowers?

• Flowers come in many shapes, sizes, and colors. Not all of them have all of the structures mentioned previously.
• A flower that has both male and female parts is called a perfect flower.
• A flower that is missing either male or female parts is called imperfect flower.

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What are some different �types of flowers?

• If a flower has sepals, petals, pistils, and stamens, we call it a complete flower.
• If a flower is missing one of those, we say it is an incomplete flower.
• Imperfect flowers are always incomplete. Incomplete flowers may or may not be imperfect.

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Essential Question:

How is a monocot flower different from a dicot flower?

Introduction to Horticulture

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How is a monocot flower different from a dicot flower?

• A good way to tell the difference between a monocot and a dicot is to look closely at the flowers.
• Monocots have flowers with flower parts in multiples of three.
• Dicots have flowers with flower parts in multiples of four or five.

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Review/Summary

• What are the parts of a flower?

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• What is the purpose of a flower?

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• What are some different types of flowers?

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• How is a monocot flower different from a dicot flower?

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Flower Dissection Activity

• Using your 2 flower (one from GH and one from me) dissect each to find the following parts: pistil, stamen, anther, filament, stigma, style, ovary, eggs, petal, sepals
• Label each of the parts both for each flower
• Label the flowers with common names and whether perfect vs. imperfect and complete vs. incomplete
• Put “good information” on it and turn it in

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