BOTANY LABORATORY PRACTICAL (PLANT ANATOMY AND MORPHOLOGY) - O.A. SHEVCHUK - 2014

THE FLOWER

TOPIC 10. STRUCTURE AND TYPES OF FRUITS. MULTIPLE FRUITS (INFRUCTESCENCES)

General notes. The fruit is designed for seed protection and dispersal, and is characteristic only of angiosperms. It develops from the flower's Ovary As a result of changes occurring after double Fertilization. The gynoecium plays the primary role in fruit formation. In some cases, other floral elements also participate in fruit formation: the receptacle, and the bases of stamens, petals, and sepals. In certain varieties of grapes and cucumbers, fruits develop without fertilization and do not produce seeds. Such fruits are called parthenocarpic.

A fruit consists of the pericarp and the seed. The pericarp develops from the ovary walls and occasionally from other PARTS OF THE flower, and consists of three layers: the exocarp (outer layer), the mesocarp (middle layer), and the endocarp (inner layer).

Fruits exhibit a vast diversity, which is due to their adaptation for dispersal. A fruit is termed simple if a single pistil is involved in its formation (e.g., pea).

Simple fruits may break apart into separate segments (e.g., caraway, maple, carrot). Therefore, they are called schizocarps. If simple fruits break along transverse partitions into one-seeded segments, they are called loments or jointed pods (e.g., wild radish).

A fruit formed by several pistils of a single flower (e.g., raspberry, buttercup) is called an aggregate or multiple fruit.

Infructescences, unlike fruits, develop from an entire inflorescence (e.g., mulberry, fig, pineapple). The formation of infructescences involves not only the flowers but also the inflorescence axis.

The further Classification of simple and aggregate fruits is based on the following characteristics: the consistency of the pericarp (dry or fleshy), the number of seeds (one or many), the manner of pericarp dehiscence (dehiscent and indehiscent fruits), the number of carpels forming the fruit, etc.

Objective: to study the definition and Biological Significance of fruits, the participation of various floral parts in their formation, the modes of fruit dehiscence and dispersal, and the principles of fruit classification.

Materials and equipment: a collection of various fruit types, fresh, dried, or preserved fruits of various plants, charts, laboratory equipment, and models.

Tasks

1. Analyze the fruit collection, determine their respective groups, and name them.

2. Study the Structural Features of fleshy fruits.

3. Study the structural features of simple fruit types.

4. Study the structural features of various types of aggregate fruits and infructescences.

5. Complete Table 4, "Types of Fruits." Indicate the characteristics of each fruit type, the plants in which they occur, and sketch the external appearance of the fruits.

Label the drawings and draw Conclusions.

Class="right">Table 4. Types of Fruits

Conclusion

QUESTIONS FOR SELF-control

1. What is the Water/144.html">Origin of the fruit? What is its Structure?

2. What are the layers of the pericarp?

3. What is the difference between simple and aggregate fruits? WHAT IS A multiple fruit (infructescence)?

4. What are the criteria for classifying simple fruits?

5. What are the Similarities and differences between a follicle, legume, silique, and capsule, as well as between a nut, acorn, achene, and caryopsis?

6. What are the similarities and differences among a berry, pome, pepo, and hesperidium?

7. What are the Characteristic Features of a drupe?

8. Which fruits are referred to as schizocarpic, and which as lomentaceous (segmented)?

9. How are aggregate fruits classified?