botany6.fruits.pdf
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May L. Medenilla1,2,3 1BS Biology Graduate, Polytechnic University of the Philippines 2 MS Biology Student, Centro Escolar University
3Instructor, Centro Escolar University
Outline
• Fruit • How are they formed?
• Function
• Types • Simple
• Multiple
• Accessory
• Aggregate
• Dispersal
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.
Fruit
• In science, the term “fruit” refers to a mature ovary that contains seeds.
• Protects the seeds that lie within
• The excess food prepared by leaves gets stored around the seeds to form the fleshy part of the fruit.
• DEHISCENT- fruits crack open along two seems and shed their seeds into the environment when the fruit is ripe.
• INDEHISCENT fruit retain their seeds and do not crack open after ripening.
Fruit
• The three fruit layers are: • Exocarp, the outermost layer often consisting of only the
epidermis • Mesocarp, or middle layer, which varies in thickness • Endocarp, which shows considerable variation from one species to
another
Fruit
•Fleshy Fruit – A simple fruit which is soft and pulpy at maturity. • Berry. The Pericarp is soft and fleshy • Drupe. The exocarp and the mesocarp are soft and
fleshy, but the endocarp and indehiscent.
Seed
Berry (simple fruit) A simple, fleshy fruit in which the fruit wall is soft throughout. Tomato (Lycopersicon lycopersicum)
Fig. 9-12a, p. 187
Single seed inside stone
Drupe (simple fruit) A simple, fleshy fruit in which the inner wall of the fruit is a hard stone.
Peach (Prunus persica)
Fig. 9-12b, p. 187
Fruit
• Dry Fruit – This is dry and hard at maturity. This is of two types, the dehiscent and indehiscent
• Capsule. Composed of two or more fused carpels
• Legume. This develops from one carpel with two sutures
• Follicle. This develops from one carpel with one sutures
• Silique. This develops from two carpels separating at maturity.
• Achene. This is a fruit with only one seed, the ovary wall and seed coat of which are separable.
Split-open suture
Seed
Capsule (simple fruit) A simple, dry fruit that splits open along two or more sutures or pores to release its seeds; fruit is formed from ovary that consists of two or more carpels.
Iris (Iris)
Fig. 9-12e, p. 187
Seed
Legume (simple fruit) A simple, dry fruit that splits open along two sutures to release its seeds; fruit is formed from ovary that consists of a single carpel.
Green bean (Phaseolus vulgaris)
Fig. 9-12d, p. 187
Seed
Follicle (simple fruit) A simple, dry fruit that splits open along one suture to release its seeds; fruit is formed from ovary that consists of a single carpel.
Milkweed (Asclepias syriaca)
Fig. 9-12c, p. 187
Single seed
Seed coat
Achene (simple fruit) A simple, dry fruit in which the fruit wall is separate from the seed coat.
Sunflower (Helianthus annuus)
Fig. 9-12g, p. 187
Fruit
• Dry Fruit – This is dry and hard at maturity. This is of two types, the dehiscent and indehiscent
• Caryopsis or Grain. One seeded fruit, the ovary wall and seed coat of which are not separable
• Samara. Has one or two seeds. Characterized by the pericarp having wing-like extensions.
• Nut. One seeded fruit from a compound ovary.
• Schizocarp. Two carpels that separate at maturity.
Fused fruit wall and seed coat
Single seed
Caryopsis (simple fruit) A simple, dry fruit in which the fruit wall is fused to the seed coat.
Wheat (Triticum)
Fig. 9-12f, p. 187
Woody fruit wall
Single seed
Scale-covered cup
Nut (simple fruit) A simple, dry fruit that has a stony wall, is usually large, and does not split open at maturity.
Oak (Quercus)
Fig. 9-12h, p. 187
Types of dry fruits
Legume
(Bean pod)
Capsule
(Poppy)
Achene
(Sunflower) Silique
(Money Plant)
Follicle
(Columbine) Nut
(Hazelnut)
Fruit
• Multiple Fruits – This is a fruit that develops from ovaries of many flowers at a common axis.
• Aggregate Fruit – This develops from separate simple fruits of a flower.
• Accessory Fruit – This is a kind of fruit with other structures other than the major parts.
MULTIPLE FRUIT
• Fruit that develops from many ovaries of many flowers growing in proximity on a common axis
• Carpels of closely associated flowers fuse, or grow together
• Example: pineapple
Seed
Mulberry (Morus)
Multiple fruit A fruit that develops from the ovaries of a group of flowers.
Fig. 9-12j, p. 187
AGGREGATE FRUIT
• Fruit that develops from a single flower with many separate ovaries
• Several separate carpels fuse, or grow together
• Example: raspberry
Seed
Aggregate fruit A fruit that develops from a single flower with several to many pistils (i.e., carpels are not fused into a single pistil).
Blackberry (Rubus)
Fig. 9-12i, p. 187
ACCESSORY FRUIT
• Fruit whose fleshy part is composed primarily of tissue other than the ovary
• Example: strawberries
Enlarged floral tube
Ovary wall Seed
Apple (Malus sylvestris)
Accessory fruit A fruit composed primarily of nonovarian tissue (such as the receptacle or floral tube).
Fig. 9-12k, p. 187
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.
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