1. KEY CONCEPT All plants alternate between two phases in their life cycles.

2. Plant life cycles alternate between producing spores and gametes.
A two-phase life cycle is called alternation of generations.
haploid phase
diploid phase
alternates between the two
fertilization
meiosis
SPOROPHYTE
PHASE
GAMETOPHYTE

3. The sporophyte is the dominant phase for seed plants.

4. KEY CONCEPT Reproduction of flowering plants takes place within flowers.

5. Flowers contain reproductive organs protected by specialized leaves.
Sepals and petals are modified leaves.
Sepals are outermost layer that protects developing flower
sepal

6. Petals can help to attract animal pollinators

7. A stamen is the male structure of the flower.
filament
anther
anther produces pollen grains
filament supports the anther

8. The innermost layer of a flower is the female carpel.
style
stigma
ovary
stigma is sticky tip
style is tube leading from stigma to ovary
ovary produces female gametophyte

9. Flowering plants can be pollinated by wind or animals.
Flowering plants pollinated when pollen grains land on stigma.
Wind pollinated flowers have small flowers and large amounts of pollen.

10. Animal pollinated flowers have larger flowers and less pollen.
many flowering plants pollinated by animal pollinators
pollen grains
pollination occurs as animal feeds from flower to flower
animal pollination more efficient than wind pollination

11. Pollination occurs when a pollen grain lands on a stigma.
pollen tube
sperm
stigma

12. Flowering plants go through the process of double fertilization.
female
gametophyte
ovule
egg
sperm
polar nuclei

13. Flowering plants go through the process of double fertilization.
endosperm
seed coat
embryo
one sperm fertilizes the egg
other sperm unites with polar nuclei, forming endosperm
endosperm provides food supply for embryo

14. Each ovule becomes a seed.
The surrounding ovary grows into a fruit.