Seed plants such as gymnosperms and angiosperms reproduce using seeds, which allow reproduction on land without needing water. Gymnosperms produce naked seeds inside cones, while angiosperms produce seeds inside flowers that are surrounded by fruits. Pollen grains carry sperm for fertilization, forming seeds that may be dispersed by animals attracted to brightly colored flowers and nutritious fruits.

1. Seed Plants
Gymnosperms & Angiosperms

2. Seeds
• Seeds are a major adaptation of land plants
that allow for reproduction without water
• As such, plants like gymnosperms and
angiosperms can be found in almost any
climate

3. Seeds
• A seed is an embryo (sperm & egg have fused)
– It contains a protective covering – seed coat
– It also has a food supply

8. Seeds
• Gymnosperms produce seeds inside of cones
• Angiosperms produce seeds inside of flowers

9. Pollen
• A pollen grain is often thought of as the
equivalent to a sperm cell, but it is actually the
entire male gametopyhte
• The sperm produced inside a pollen grain do
not swim, they are carried to the egg by wind,
insects or animals
– This is known as pollination

11. Cones
• Cones are the structures that gymnosperms
use to produce both male and female
gametophytes
• Male cones produce pollen
– Contains the “sperm” cells
• Female cones produce ovules
– Contains the egg cells

14. Pollination
• Pollen grains (gametophyte) are carried from
the male cone of one plant, to ovules
(gametopyhte) in the female cone of another
plant.
– Can be same plant, but not typically
• Once a gamete from the pollen grain meets
the egg inside the ovule, the two cells fuse,
eventually making an embryo inside of a seed.

15. Alternation of generations
• As with ferns, the sporophyte is the dominant
stage of the life cycle for gymnosperms.
• Trees like spruce, are the sporophyte, the
pollen grains and ovules formed inside of its
cones are the gametophyte

17. Gymnosperms
• Gymnosperms produce seeds that are
exposed or naked
– They have nothing covering them
– …unlike angiosperms that have a fruit surrounding
their seeds.

18. Angiosperms
• Unlike gymnosperms, their gametes, and
eventual seeds are made within flowers
• Whereas gymnosperms produce “naked”
seeds, angiosperms have their seeds
surrounded by a fruit

19. Flower Anatomy

20. Flower Anatomy

21. Stamen
• The stamen is the male structure of the
flowering plant
– Anther (makes pollen grains)
– Filament (holds anther)
• The pollen grain is the male gametophyte b/c
is makes the male gamete

22. Stamen

23. Flower Anatomy

24. Pistil/Carpel
• The pistil is the female structure of a
flowering plant
• The pistil may be made up of one or more
carpels
• The carpel consists of:
– 1 stigma
– 1 style
– 1 ovary

25. Pistil/Carpel

26. Pollination
• Pollination is the act of a pollen grain being
transport from the anther (male) to the
stigma (female) to allow for fertilization
– When this happens within the same flower it is
know as self-pollination
• Insects, birds, and wind are the most common
pollinators.

27. Fertilization
• Once the pollen grain lands on a stigma, the
male gametes inside still need to make it to
the female gametes in the ovules.
• A pollen tube burrows out from the grain, and
down through the style to the ovary and
ovules, delivering the sperm cell to the egg
cell for fertilization.
– Fertilization will result in an embryo within a seed!

28. Pollen tubes/Fertilization

33. Petals
• Petals are modified leave of the plants
• They protect the male and female
reproductive organs early on
• Usually brightly colored to attract pollinators
when the plant is mature

40. Fruits
• In biology, a fruit is anything that surrounds a
seed of a flowering plant
• The ovary, on fertilized becomes the fruit, just
as the fertilized ovules become the seeds.

45. Fruits?

46. Fruits?

47. Fruits
• The role of a fruit is to encourage animals to
eat them, so that seeds may be carried away
from where they were made
• They also serve as a form of added protection
in some cases.