Transcript Flower - Xavier High School

Flower
The organ responsible
for sexual
reproduction in plants
Function-







produce gametes
pollination
fertilization
develop seeds
develop fruit
4 Basic Whorls of a Flower


Calyx- Outermost
Whorl

All of the sepals
collectively
Corolla- 2nd
Outermost Whorl

All of the petals
collectively
4 Basic Whorls of a Flower


Stamen- 3rd Outermost
Whorl
 Male structure of the
flower
Pistil- Made of fused
carpels- Innermost
Whorl
 Female structure of
flower
Diagram 1- Flower Structure

1. Petals

Colorful leaf-like parts,
attract animals/insects,
aids in pollination
2. Stamen
Male structure
Diagram 1- Flower Structure

3. Pistil

Female structure
4. Pedicel/Receptacle
Stalk like part, supports
the flower
Diagram 1- Flower Structure

5. Sepals

Small leaves that
surround and protect the
flower bud
6. Stigma
Sticky top to the pistil,
collects the pollen during
pollination
Diagram 1- Flower Structure

7. Style

Long stalk like part that
extends from ovary,
supports the stigma
8. Ovule
Located inside the
ovaries, will develop into
a seed after fertilization
Diagram 1- Flower Structure

9. Ovary

Enlarged base of the
pistil, will develop into
fruit after fertilization
10. Filament
Slender stalk that
supports the anther of the
stamen
Diagram 1- Flower Structure

11. Pollen

Formed in the anther,
contains 2 nuclei, 1 tube
nucleus, 1 generative
nucleus
12. Anther
Knob like end of the
stamen, forms the sperm
nuclei and the pollen
grains
Diagram 2- Pollination (p 617)


The transfer of pollen
from the anther to the
stigma of flowers
Usually aided by insects
or wind
Diagram 2- 2 types
Self pollination




Same plant
Either the same flower
or 2 flowers on the
same plant
Or 2 genetically
identical plants
Cross pollination


Two genetically
different plants
Diagram 2- Pollination 
Fertilization (p 617)

2 separate events

Pollination occurs on the
stigma

Fertilization occurs in
the ovule
Diagram 2- After Pollination (p 617)

Pollen grain releases tube & generative
nucleus into pistil



#14. Tube nucleus develops pollen tube
#13. Two sperm nuclei- from mitosis of the
generative nucleus
#15. Pollen tube develops through style to ovule

2 sperm nuclei travel through tube to ovule
Diagram 2- Fertilization (p 617)

Double fertilization in
the ovule

One sperm nucleus
fertilizes (#16) egg
nucleus to form the
zygote (fertilized egg),
this becomes the
embryonic plant of the
seed
Diagram 2- Fertilization (p 617)

Second sperm nucleus
unites with (#17) 2 polar
bodies, forms triploid
(3n) cell that develops
into endosperm of the
seed
Diagram 3- Gamete FormationMale (p 615)







Occurs in anther
Sketch
Diploid 
Meiosis 
4 haploid cells 
Mitosis 
Pollen grain with 2
nuclei
Diagram 3- Gamete FormationFemale (p 615)










Occurs in ovule
Sketch
Diploid 
meiosis 
4 haploid cells(3 die) 
mitosis 
mitosis 
mitosis 
8 haploid cells (5 die) 
3 haploid cells
Seed (p 620)
An embryonic plant with
a food source
Grows into a new plant










Germination
Water, temp., oxygen
Plumule (shoot tip
w/embryonic leaves)
Epicotyl (stem)
Hypocotyl
Radicle (root)
Cotyledon (food source)
Endosperm (food source)
Fruit (pp 618, 619)


Surrounds seeds
Dispersal of seedsspread seeds around



Wind
Water
Animals


Edible
Carrier