Plant Anatomy PowerPoint Presentation, PPT - DocSlides

Plant Anatomy

Unit 1Chapter 6Lesson 4

Flowers, Fruits, & Seeds

Flowers are pretty & contain nectar in order to attract insectsThese insects fertilize the flower by pollinationPollination begins fruit and seed formation

Fruits & Seeds

Fruits and seeds are eaten, collected, and spread out by animals and peopleThis reproduces the plant

Seeds

Seeds have special devices to ensure propagation Some seeds are sticky (thistles), some float in the wind (dandelions), others can survive stomach acid (cherry pits)

Flower Parts

Flowers differ in shape, size, and color, but all have relatively the same parts

Flower Parts cont.

Seeds are the most common way plants reproduce in nature Sexual process involving male and female parentsA complete flower has both male and female parts Only one parent is needed if a plant is self-fruitful, or can pollinate itself

Flower Parts cont.

4 main parts SepalsPetalsStamensPistil

The Sepals

Green, leaf like parts of the flower that cover and protect the flower bud before it is open

Petals

Are actually leavesGenerally the most striking part of the flowerBright colors are used to attract insects for pollination

The Stamens

Male reproductive partEach stamen consists of:FilamentAnther – contains the pollen (male sex cell)

The Pistil

Located in the center of the flowerFemale partProduces female sex cells (eggs or ovules)If fertilized, the eggs become seeds

Parts of the Pistil

3 main parts:Stigma – sticky, catches the pollenStyle – tube that leads to the ovaryOvary – eggs develop here, after fertilization the ovary grows to become a fruit or seed coat

Flower Construction

Insects looking for nectar have to climb over the anther and brush pollen on their legsAs they climb towards the center looking for food, they deposit pollen on the stigma

Fertilization

After an insect deposits pollen, fertilization begins!The pollen grain sprouts and sends a long stalk (pollen tube) down the style to the ovary

Fertilization cont.

The pollen sperm cell can then fertilize the female egg cells and seeds begin to developThe ovary enlarges into a seed coat or fruit

Pollen

Incomplete Flower

Has ONLY male parts or female parts Male flower – sepals, petals & stamens but no pistilFemale flower – sepals, petals, & pistil, but no stamensExamples: Kiwi, Ginkgo

Flowers are Important!

Many plants are grown only for their flowersFloriculture industry in a multimillion dollar business!!!

What is the major function of flowers?

Reproduction of the Plant

What is a fruit?

A ripened flower ovaryBotanically, fruits = vegetables & vegetables = fruitsIn most plants, a fruit is formed following fertilization of the ovulesThey contain seeds

What about seedless fruit?

Seedless fruit -- fruit that form without pollination or fertilizationThese fruit are called PARTHENOCARPICExamples: Banana, navel orange

When the fruit ripens, the ovary wall thickens.

This is called the pericarpThe pericarp has three sections:The endocarpThe mesocarpThe exocarp

Types of Fruits

Aggregate fruitsMultiple fruitsSimple fruits

Key Flower Terms

Flower

Reproductive organ of the plant

Pedicel

Flower stem

Receptacle

Tip of the pedicel that holds the flower parts

Sepals

Leaf-like structure that is the exterior portion of the flower

Key Flower Terms

Calyx

The term for all of the sepals or a flower, collectively

Corolla

The term for all of the petals of a flower, collectively

Perianth

The term for the sepals and petals of a flower, together

Key Flower Terms

Tepals

Term used when there is not a clear distinction between the petals and sepal of the flower

Stamen

Male part of the flower

Made of anther and filament

Produces the pollen

Pistil

Female part of the flower

Contains the stigma, style, and ovary

Produces the ovules (eggs) of the flower

Key Flower Terms

Complete flower

Flowers that have sepals, petals, stamens, and a pistil

Incomplete flower

A flower that lacks 1 or more of the parts of a complete flower

Perfect flowers

Have both male and female parts

Imperfect flowers

Flowers that lack 1 or more sex structures

Key Flower Terms

Solitary flowers

Stem with only one flower on it

Tulip, narcissus, rose

Inflorescence

Plants with flower clusters

Peduncle

Main stem of an inflorescence

Determinate

When the first flower to open is at the apex with progression moving down the stem

Key Flower Terms

Indeterminate

Last flower to open is at the apex as the flowering had an upward movement