1a4 Fruits & Seeds

Fruit & Seeds The next generation of flowering plants

gTe5G8KLc
4

Fruit & Seeds Objectives

  • Discuss seeds, including the parts of a seed, the process of germination, and examples of commercially important seeds.
  • Classify different types of dry and fleshy fruits.
  • Provide examples of different forms of fruit and seed dispersal.
lilyanatomy

A quick review of flowers:

Can you identify the stamen (pollen on the anther, attached to a long filament) and the stigma the pollen would land on with the style that carries the pollen down to the ovary?

Now we are focusing on what is produced after flowers are pollinated: fruit and seeds.

Since fruits may mature weeks or months after flowering, many people do not visualize the flower that produces a fruit.  Tomato plants, like the roses can simultaneously display both flowers and developing fruit.

These are the general signals of seasonal changes far from the equator: spring is for flowers, summer is for developing fruit, and autumn is for harvest.  You can predict the season when we made this video.

Seed Structure and Germination

bean seed anatomy 1

Most of a bean seed is made up of two large kidney-shaped, fleshy cotyledons (or seed leaves), which serve as food storage structures.  Between the two cotyledons, is the small body of the embryo.  The embryo includes the radicle (future roots) and embryonic true leaves.

The hypocotyl and epicotyl are the future plant’s stem, and the endosperm refers to stored energy the seedling will rely on until it can photosynthesize.  The seed coat protects the cotyledons and embryo, the hilum connects the seed to the fruit.

bead growth 1

Moisture, temperature, and/or day length can trigger germination, the development of a seed into a seedling.

Cotyledons support the developing seedling with nutrients and can in many cases also carry out photosynthesis.

These models and preserved specimens show stages of bean germination.

Beans (dicots) and corn (monocots) appear significantly different in the garden as they emerge from the ground.

Economically Important Seeds

This video provides an overview of seeds that are especially important to humans.

Grains from grasses provide almost half of the energy (calories) in the human diet.

Fruit Structure and Function

From your own background knowledge; fruit develop from plants that have _____.  What are the primary functions of fruit? _______

Answers: flowers; protect & disperse seeds
fruit nuts

A fruit is a ripened (mature) ovary that protects and may disperse seeds. When the fruit ripens, it can be fleshy (moist) or dry.

There are two general categories of fleshy fruits (complex or simple) and two general categories of dry fruit (ones that rupture or others that don’t).

Fleshy Fruits – Simple

This video provides an overview of fleshy fruits.

Fleshy Fruits – Simple

Thin outer skin, center of fruit has a single large stone or pit. Examples: cherry, peach, mango, coconut, olive, coffee

Drupe

Thin outer skin, center of fruit has a single large stone or pit. Examples: cherry, peach, mango, coconut, olive, coffee
Thin outer skin, center of fruit has a papery barrier that surrounds several seeds. Examples: apple, pear, quince

Pome

Thin outer skin, center of fruit has a papery barrier that surrounds several seeds. Examples: apple, pear, quince
Thin outer skin, center of fruit lacks a papery barrier and is soft. Examples: grape, tomato, pepper, kiwi, passionfruit, currant

Berry

Thin outer skin, center of fruit lacks a papery barrier and is soft. Examples: grape, tomato, pepper, kiwi, passionfruit, currant
Firm or leathery outer skin, inside of fruit is divided into segments. Examples: lemon, orange, grapefruit, pummelo

Hesperidium

Firm or leathery outer skin, inside of fruit is divided into segments. Examples: lemon, orange, grapefruit, pummelo
Firm or leathery outer skin, inside of fruit is not divided into segments. Examples: melon, squash, cantaloupe, pumpkin

Pepo

Firm or leathery outer skin, inside of fruit is not divided into segments. Examples: melon, squash, cantaloupe, pumpkin
Different fruit structures may relate to the primary roles of a fruit: to protect and disperse the seeds.

Fleshy Fruits – Complex

Fruit is produced from many flowers, with one ovary each. Examples: pineapple, fig

Multiple Fruits

Fruit is produced from many flowers, with one ovary each. Examples: pineapple, fig
Fruit is from one flower with many ovaries. Examples: strawberries, blackberries

Aggregate Fruits

Fruit is from one flower with many ovaries. Examples: strawberries, blackberries
Are peppers fruits or vegetables?

Find out here.

Dry Fruits

This video provides an overview of dry fruits.

Dry Fruits – that do not rupture open

Thin fruit wall with a single seed that attaches to the ovary wall at a single point. Examples: buckwheat, dandelion

Achene

Thin fruit wall with a single seed that attaches to the ovary wall at a single point. Examples: buckwheat, dandelion
An achene with a wing-like appendage. Examples: ash, elm, maple

Samara

An achene with a wing-like appendage. Examples: ash, elm, maple
Thin fruit wall with a single seed that attaches completely to the ovary wall. Examples: corn, rice, wheat

Caryopsis

Thin fruit wall with a single seed that attaches completely to the ovary wall. Examples: corn, rice, wheat
Hard husk surrounds a single seed. Examples: chestnut, hazelnut, walnut

Nut

Hard husk surrounds a single seed. Examples: chestnut, hazelnut, walnut

Dry Fruits – that rupture open

Multiple seed compartments within fruit. Examples: okra, horse chestnut

Capsule

Multiple seed compartments within fruit. Examples: okra, horse chestnut
Single seed compartment that splits open along two seams (lines). Examples: soybeans, peas, peanuts

Legume

Single seed compartment that splits open along two seams (lines). Examples: soybeans, peas, peanuts
Like legumes, but with a two-segmented pod. Examples: cabbage, radish, mustard

Silique

Like legumes, but with a two-segmented pod. Examples: cabbage, radish, mustard

Check your knowledge: which of these are fleshy fruits and which are dry?

Dry fruits in the video are: nut, samara, achene, silicle, legume, capsule, caryopsis

Sometimes you will get quiz cues directly in the Guide videos, like here:

Why may it be important for seeds to be dispersed far from a parent plant?

Fruit & Seed Dispersal

Fruits often have modifications that enable seeds to disperse far from the parent plant, reducing potential competition.

Six types of fruit (and seed) dispersal

Fruit are lightweight and can act like sails and wings. Examples include maple, elm, dandelion, and fireweed.

Wind

Fruit are lightweight and can act like sails and wings. Examples include maple, elm, dandelion, and fireweed.
Fruit have structures that can attach to animals skin. Examples include burdock and thistle.

Animals: Burrs and Stickseeds

Fruit have structures that can attach to animals skin. Examples include burdock and thistle.
Animals eat a fruit and either spit out the seeds or egest them in fecal material. Examples include rose hips, cherries, and berries.

Animals: Fleshy Fruit

Animals eat a fruit and either spit out the seeds or egest them in fecal material. Examples include rose hips, cherries, and berries.
High-energy dry fruits are stored by animals like squirrels and woodpeckers. Some of the seeds survive and germinate. Examples include acorns and walnuts.

Animals: Stored Nuts

High-energy dry fruits are stored by animals like squirrels and woodpeckers. Some of the seeds survive and germinate. Examples include acorns and walnuts.
The fruit dries and untwists, flinging seeds far from the parent plant. Examples include lupine and vetch.

Propulsion: Twisting

The fruit dries and untwists, flinging seeds far from the parent plant. Examples include lupine and vetch.
Fruit dry and shoot seeds into the air. We hear popping sounds on a dry summer day.

Propulsion: Ballisitics

Fruit dry and shoot seeds into the air. We hear popping sounds on a dry summer day.

This video uses specimens to demonstrate fruits dispersing seeds.

Himalayan blackberries are invasive species in many parts of the northern hemisphere, including the willamette valley.  You can see both the flowers and developing fruit in this video.  

How are these fruits likely dispersed?

Maple trees produce dry samara fruits.  This video shows the fruit in action, aiding in seed dispersal.

Many people are planting milkweed seeds because some of the species play a critical role in butterfly life cycles.  This video shows how they can spread through a field.

1a4 Fruits & Seeds

Finish your notes here

This is the end of Guide 1A’s content.  After you check your knowledge over the material, proceed to the product page.

4 1

Check your knowledge.  Can you:

  • discuss seeds, including the parts of a seed, the process of germination, and examples of commercially important seeds?
  • classify different types of dry and fleshy fruits?
  • provide examples of different forms of fruit and seed dispersal?
1a4 Fruits & Seeds

Go back to the Flowers Page

1a4 Fruits & Seeds

Guide 1A Product Page

Biodiversity Guide Contents

Complete all four of these sections before taking the quiz and submitting your two journal pages.
Patterns of Nature

Patterns of Nature

Classification

Classification

Flowers

Flowers

Fruits & Seeds - YOU ARE HERE

Fruits & Seeds - YOU ARE HERE

1a4 Fruits & Seeds

Back to Module Index

Links to Modules & Guides
1a4 Fruits & Seeds

This Guide’s Home Page

1A: Biodiversity
1a4 Fruits & Seeds

This Guide’s Assignments

1A: Biodiversity Products
1a4 Fruits & Seeds

Direct Link to Canvas

Submit Products