Fruit & Seeds The next generation of flowering plants

Fruit & Seeds Outcomes

Identify the parts of a seed.
Classify different types of fruits.
Provide examples of fruit and seed dispersal.

A quick reminder of last week\’s Flowers activity. 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?

Last week\’s activity focused on the structures of flowers. This week \’s laboratory focuses on what is produced after flowers are pollinated: fruit and seeds.

This video demonstrates a rose that can have flowers and fruit developing on the same plant.

Let\’s start with basic seed structure.

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.

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.

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

Answers: flowers; protect & disperse seeds

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 – Complex

Multiple Fruits

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

Aggregate Fruits

Fruit is from one flower with many ovaries. Examples: strawberries, blackberries

Fleshy Fruits – Simple

Drupe

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

Pome

Thin outer skin, center of fruit has a papery barrier that surrounds several seeds. Examples: apple, pear, quince

Berry

Thin outer skin, center of fruit lacks a papery barrier and is soft. Examples: grape, tomato, pepper, kiwi, passionfruit, currant

Hesperidium

Firm or leathery outer skin, inside of fruit is divided into segments. Examples: lemon, orange, grapefruit, pummelo

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.

Dry Fruits – that rupture open

Capsule

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

Legume

Single seed compartment that splits open along two seams (lines). Examples: soybeans, peas, peanuts

Silique

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

Dry Fruits – that do not rupture open

Achene

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

Samara

An achene with a wing-like appendage. Examples: ash, elm, maple

Caryopsis

Thin fruit wall with a single seed that attaches completely to the ovary wall. Examples: corn, rice, wheat

Nut

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

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

Six types of fruit (and seed) dispersal

Wind

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

Animals: Burrs and Stickseeds

Fruit have structures that can attach to animals skin. Examples include burdock and thistle.

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.

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.

Propulsion: Twisting

The fruit dries and untwists, flinging seeds far from the parent plant. Examples include lupine and vetch.

Propulsion: Ballisitics

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

Fruit & Seeds The next generation of flowering plants

Fruit & Seeds Outcomes

Identify the parts of a seed.

Classify different types of fruits.

Provide examples of fruit and seed dispersal.