BIOLOGY – 328 LAB BIOLOGY – 328 LAB Plants and Plants and People People

Objective

To understand what a fruit is

To study different parts of fruit

To learn different types of fruits

Background

Different parts of a fruit

Exocarp – Outermost layer Endocarp – Innermost layer Mesocarp – Middle layer

Pericarp - All three layers not recognizable

Rind - Thick leathery covering exocarp (eg, water melons) or fusion of exocarp and mesocarp (eg. Orange)

Accessory fruit – Fruits not derived from ovary

e.g. apple

Classification of fruits

Simple fruit – Fruit from a single flower and single ovary

Aggregate fruit – Fruit from a single flower but several ovaries eg. Blackberry, strawberry

Multiple fruit – Fruit from multiple flowers in the same peduncle eg. Pineapple, Mulberry

Simple fruits

Dry dehiscent fruit – Pericarp dries and splits open when ripe. Follicle – 1 locule that splits along one suture

e.g. Sweet gum Legume/pod – 1 locule and splits along 2

sutures

e.g. Beans Capsule – 3 or more locules and splits in 3 or

more sutures

e.g. Okra

Simple fruits

Dry indehiscent fruit – Pericarp dries but does not split when ripe Samara – 1 or 2 seeded with pericarp flattened

into wings e.g. maple Grain/Caryopsis – 1 seeded fruit with seed

fused to pericarp e.g. corn Achene – 1 seeded fruit with seed free from

pericarp

e.g. sunflower Nut – 1 seeded fruit enclosed in husk

e.g. Pecan

Simple fruits

Fleshy fruit- Pericarp doesn't dry when ripe Berry – entire pericarp is fleshy e.g. Grape

Pepo – Exocarp is a hard rind e.g. Melons

Hesperidium – Exocarp and mesocarp is a hard rind, endocarp has juice vesicles e.g. Orange

Drupe or stone – a single seeded fruit fuzzy or smooth skin, fleshy mesocarp and a hard stony endocarp

e.g. Peach

Pome – Fleshy receptacle, hypanthium with papery pericarp e.g. Apple

Today’s Lab

Carefully examine the fruits, paying special attention to their morphology, structure, family and scientific name, and geographic origin. During the exercise, answer the following questions for each fruit observed.

1. What is the fruit type?

2. How many carpels are present?

3. How might they might be dispersed in nature.

Summary

Today’s Lab Types of fruits and

characteristics

Next week’s lab – Major Families I

Quiz on Fruits