Flowers: Structure and Function of Male & Female Components
- 0:05 Quick Review of Flower Types
- 0:59 Complete vs. Incomplete Flowers
- 2:42 Male and Female Components
- 5:22 Lesson Summary
In this lesson, we'll look at the parts of a flower and learn their functions. These natural beauties provide indispensable services to the plants they adorn.
Quick Review of Flower Types
Flowers serve several purposes in our lives. You may think of giving flowers to friends or loved ones to show them that you care or that you are sorry. However, flowers serve many vital roles for plants. Let's look at the roles that flowers play as well as their male and female components.
As we look at the parts of a basic flower, we will look back at this diagram. Before getting into the parts of the flower, we first need to review which types of plants have flowers. You may remember that plants are divided into several groups. The first division was vascular and nonvascular. Nonvascular plants do not have flowers. Vascular plants were divided into gymnosperms and angiosperms. Gymnosperms also do not have flowers. That means that only angiosperms have flowers. Both divisions of angiosperms - the monocots and the dicots - have the same basic structures in their flowers.
Complete Versus Incomplete Flowers
Flowers can be described as either complete or incomplete. Complete flowers are those that have all four whorls of parts, while incomplete flowers are those that lack one or more of the whorls. These definitions may leave you asking 'What are whorls?' In flowers, there are different layers of parts that are described as whorls. There are four possible whorls, including the calyx, corolla, androecium and gynoecium. Let's look at each part more closely.
The calyx is the outermost whorl that protects the flower. The calyx generally contains flat structures that protect the flower when it is a bud or before it blooms. These structures are called sepals. This part of the plant is considered sterile because it does not contain any reproductive structures. Let's go back to our diagram and label the calyx. We can see in the first part when the flower is still in bud that the calyx - containing the sepals - surrounds and protects the bud. However, when the flower is in bloom, the sepals are less obvious and are generally below the bloom.
The whorl directly inside the calyx is called the corolla and may be the most familiar part of the flower. The corolla contains petals. When you think of flowers, you most likely either think of petals or allergies. We'll get to what causes allergies shortly, but the petals make up the second whorl of the flowers. The purpose of petals is to attract pollinators. The color and style of the petals on a flower help indicate the type of pollinator it is trying to attract. For example, flowers that attract pollinators such as hummingbirds are often bright red, but those flowers that attract pollinators such as bees are blue or yellow. Let's label the corolla on our diagram.
Male and Female Components
The last two whorls contain the male and female parts of the flower. Remember that if one of these whorls is missing, the flower is considered to be incomplete. However, if it contains all four parts - including both the male and female parts - then the flower is complete.
Let's first look at the male parts. The whorl that contains the male parts is called the androecium. Knowing the roots of this word will help you remember that it contains the male parts. The Greek word 'andros' means 'man,' and the word 'oikos' means 'house.' When these are put together, 'androecium' literally means 'man house.'
The main structure in the androecium is called the stamen and is the male structures in the flower. The stamen is made of two parts: the filaments and the anthers. The filaments are the slender stalks of the stamen seen here. The anther is the top of the stamen and contains pollen. We can see the anther here on top of the filament. When you look at a flower, the anthers often appear a yellowish color because they contain pollen. This pollen is often what causes allergies or can just make you sneeze if you sniff a flower too closely. Let's label the androecium on our diagram. We can see the stamen with the filament and anther within this whorl of the flower.
The innermost whorl contains the female parts and is called the gynoecium. Again, let's look at the root words. The Greek word 'gyne' means 'woman,' and we already know that 'oikos' means 'house.' So, the word 'gynoecium' means 'woman house.' There are several female parts in flower, so let's look at these more closely.
The female part that is easiest to see in the flower is the carpel. The carpel contains the ovules, ovary, style and stigma. Flowers often contain either one or two carpels. The outer parts of the carpel that you may see are the style and the stigma. The stigma is the top, pollen-receiving structure. It is sticky so that the pollen will stay on the stigma and can then fertilize the plant. If there are two carpels, then there are two stigmas.
Below the stigma is the style, which is the narrow part between the stigma and the ovary. We can see this in the picture here. The stigma is the top flat part, and this narrow tube is the style. The part directly below the style is the ovary. This swollen part at the bottom of the carpel produces ovules. We can also see this in our diagram here. Ovules, which are produced in the ovary, develop into seeds. As you can see, the gynoecium has a few more parts than the androecium.
All parts of the flower serve a distinctive purpose. The outermost layer is the calyx, which has sepals that protect the flower when it is still a bud. The main part of the flower that you recognize is the corolla, which is made up of the petals. This generally colorful part of the flower helps to attract pollinators.
Next we looked at the male structures of the plant, which were found in the androecium. In here we found the stamen, which is made up of filaments and anthers. The anthers produce pollen and are located at the top of the stamen. The last whorl we looked at was the gynoecium, which contains the female parts. Flowers may have one or two carpels, which contain:
- the stigma - the top sticky part that catches pollen
- the style - the narrow tube supporting the stigma
- the ovary - the swollen part at the bottom that produces ovules that develop into seeds.
Remember that when a flower contains all four whorls it is considered to be complete. However, if one or more whorls are missing, the flower is incomplete.
Chapters in Biology 101: Intro to Biology
- 1. Science Basics (6 lessons)
- 2. Review of Inorganic Chemistry For Biologists (14 lessons)
- 3. Introduction to Organic Chemistry (8 lessons)
- 4. Nucleic Acids: DNA and RNA (4 lessons)
- 5. Enzymatic Biochemistry (4 lessons)
- 6. Cell Biology (14 lessons)
- 7. DNA Replication: Processes and Steps (5 lessons)
- 8. The Transcription and Translation Process (10 lessons)
- 9. Genetic Mutations (4 lessons)
- 10. Metabolic Biochemistry (9 lessons)
- 11. Cell Division (13 lessons)
- 12. Plant Biology (12 lessons)
- 13. Plant Reproduction and Growth (10 lessons)
- 14. Physiology I: The Circulatory, Respiratory, Digestive,... (12 lessons)
- 15. Physiology II: The Nervous, Immune, and Endocrine Systems (13 lessons)
- 16. Animal Reproduction and Development (12 lessons)
- 17. Genetics: Principles of Heredity (10 lessons)
- 18. Principles of Ecology (18 lessons)
- 19. Principles of Evolution (9 lessons)
- 20. The Origin and History of Life On Earth (4 lessons)
- 21. Phylogeny and the Classification of Organisms (7 lessons)
- 22. Social Biology (6 lessons)
- 23. Basic Molecular Biology Laboratory Techniques (13 lessons)
- 24. Analyzing Scientific Data (3 lessons)
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