Fruits and SeedsPrepared by

Pooja KhanparaAPIP,Jamnagar

Fruits

From ovary to fruit

• The ovary of the flower contains the ovules.

• As fertilized ovules develop into seeds, the ovary wall develops into the fruit.

• In science, the term “fruit” refers to a mature ovary that contains seeds.

Fruit anatomy

Types of dry fruits

Legume(Bean pod)

Capsule(Poppy)

Achene(Sunflower)

Silique(Money Plant)

Follicle(Columbine)

Nut(Hazelnut)

Types of fleshy fruits

Drupe(Peach)

Pome(Apple)

Pepo(Cucumber)

Aggregate(Strawberry)

Multiple(Pineapple)

Berry(Tomato)

Fruit dispersal

• The form of the fruit gives clues about its dispersal.

• Small, dry fruits with “wings” or “parachutes” may be wind-dispersed. Fleshy fruits are often animal dispersed. Explosive fruits can fling seeds away. Floating fruits may be water dispersed.

How are these fruits dispersed?

Dandelion Coconut

Maple

Cocklebur Jewelweed

Seeds

Ovule to seed

Mature Seed

Seed anatomy

Seed dormancy

• Seeds can remain dormant in the soil for long periods of time. Dormancy helps ensure that seeds only germinate when conditions are right.

• When we weed or cultivate a bare patch of soil, the weeds that sprout up immediately usually come from the “seed bank” already in the soil.

Breaking dormancy

• Seeds require moisture and the right temperature to germinate.

• In addition, some seeds germinate only after certain environmental signals:

• Drying

• Temperature (period of cold or heat)

• Disruption of the seed coat

Germination: monocot

Germination: dicot

What is a seed?• A seed is a small embryonic plant enclosed in a

covering called the seed coat, usually with some stored food.

• The formation of the seed completes the process of reproduction in seed plants.

Why are seeds advantageous for plants?

• maintain dormancy until better environmental conditions arise

• afford protection to young plant at vulnerable developmental stage

• contain adequate food supply until photosynthesis is possible

• dispersal of plants

SEED STRUCTURE• External

• Seed coat (testa)

• Hilum

• Embryo

• Cotyledon

• Epicotyl / Hypocotyl

• Pumule

• Radical

Seed Coat• AKA testa

• The seed coat protects the embryo

• Can be of varying thicknesses, depending on the seed type.

Hilum

• Scar from the seed being attached to the parent plant

Cotyledon• The cotyledon is the

first leaf that germinates.

• It is filled with stored food that the plant uses before it begins photosynthesis.

• Some plants have 1 cotyledon (monocot) and some have 2 cotyledons (dicot).

Epicotyl /Hypocotyl

• The basis for the plant’s stem.

• It is known as the epicotyl above the cotyledon and a hypocotyl below the cotyledon.

• These grow upward in response to light.

Plumule

The shoot tip with a pair of miniature leaves.

The Radicle

• The part of the seed where the root develops.

SEED DISSECTION

• MATERIALS

• Soaked pinto seed

• Dissecting microscope

• Tweezers

• Ruler

SEED DISSECTION• EXTERNAL

• Draw the external pinto bean

• Label structures from notes

• INTERNAL

• Carefully remove the seed coat.

• Gently pull apart the two halves of the seed.

• Examine each half with the dissecting microscope

• Draw what you see inside the bean

• Label structures from notes

REVIEW THE RULES FOR LAB DRAWING IN YOUR STUDENT GUIDE

BE SURE YOU MEASURE AND RECORD THE LENGTH OF YOUR SEED

Plumule

Cotyledon

Embryo HypocotylEpicotyl

Radicle