1. The Reproductive Body: Fruits and Seeds
PBIO 006
Spring 2012
Chapter 6

2. Outline
I. Seed Structure and Germination
II. Fruit Types
III. Fruit Dispersal

3. So what is a seed again?
A brief review…

5. S E D T R U C
Polar
nuclei

6. Seed coat (derived from integument)
Endosperm
Food supply (female gametophyte tissue) (n)
Embryonic plant
Embryo (2n) (new sporophyte)
(c) Gymnosperm seed

8. S E D T R U C

9. S cotyledons E D hypocotyl G R M I N A epicotyl T (not visible) O
radicle
lev70065_06_02.jpg
Dicot embryo

10. S E D G R M I N A T O
Radicle
lev70065_06_02.jpg

11. Fruit
Ovary to fruit

13. Kinds of Fruits

14. True Fruits A true fruit develops from a single
ovary of a single flower

15. Fleshy fruits Usually these are indehsicent (which is to say they don’t open up to release their seeds)

16. Berry: the entire pericarp is soft

17. Drupe: The pericarp is divided into three layers

18. Dry fruits (these may be dehiscent or not )

19. A follicle is a dry fruit that splits open
to release its seeds (it’s dehiscent)

20. Capsule: a dry, dehiscent fruit from a compound pistil

21. An achene is a dry, indehiscent fruit

22. A false fruit does not develop from a single ovary of a single flower.
False Fruits
A false fruit does not develop from a single ovary of a single flower.

23. The strawberry is an accessory fruit: the sweet, juicy part
is receptacle, not ovary wall!

24. A raspberry is an aggregate fruit: each little “unit” is the product of a separate ovary.

25. The pineapple is an example of a multiple fruit: the fruit is derived from the fusion of an entire inflorescence.

26. True
True
True
lev70065_06_01.jpg F A L S E
Accessory

27. Q. What kind of fruit is an olive?
Clicker Question
Q. What kind of fruit is an olive?
A berry
A capsule
A drupe
A pome
It’s not a fruit, it’s a vegetable

28. Fruit Dispersal

29. Fleshy fruits are dispersed by birds and other frugivorous animals.

30. Some fruits are designed to be dispersed by unwitting animals.

31. Winged fruits are dispersed by the wind

32. So are the fruits of dandelions.

33. Coconuts are dispersed
by water.

34. Fruit structure is determined by two things:
The structure of the gynoecium (pistil or pistils) from which it formed.
Adaptations for dispersal of the fruit and the seeds.