Reproduction of flower plants Watch Video Below Copyright Pearson Prentice Hall

Reproduction of flower plantsWatch Video Below

Copyright Pearson Prentice Hall

http://www.youtube.com/watch?v=ExaQ8shhkw8&feature=player_embedded


IB ASSESSMENT STATEMENT

9.3.1 Draw and label a diagram showing the structure of dicotyledonous animal-pollinated flower and plants.

Know the location and function of following structures

•Sepal

•Petal

•Anther

•Filaments

•Stigma

•Style

•ovary


Structure of Flowers

Function of Flowers

Flowers are reproductive organs.



Sepals enclose the bud before it opens and protect the flower while it is developing.

Sepal



Petals are often brightly colored and are found just inside the sepals.

Petals attract insects and other pollinators to the flower.

Petal



The male parts of a flower consist of an anther and a filament, which together make up the stamen.

Filament

AntherStamen



An anther is an oval sac where meiosis takes place, producing pollen grains (male sex cells).

Anther



The filament is a long, thin stalk that supports an anther.

Filament



The innermost floral parts are carpels, also called pistils, which produce the female gametophytes.

Carpel Style

Stigma

Ovary



Each carpel has a broad base forming an ovary.

The ovary contains one or more ovules where female sex cells are produced.

Ovary

Ovule



The narrow stalk of the carpel is the style.

Style



At the top of the style is the stigma—a sticky portion where pollen grains frequently land.

Stigma



Ovary

Ovule

Carpel Style

Stigma

Ovary

Filament

AntherStamen

Parts of a Typical Flower

Sepal

Petal

Flower structure

Stigma

Style

OvaryPetal

Sepal

Filament

Anther

© 2008 Paul Billiet ODWS

http://www.saburchill.com/IBbiology/bio_hp.html



9.3.1 Draw and label a diagram showing the structure of dicotyledonous animal-pollinated flower and plants.

Know the location and function of following structures

Sepal

Petal

Anther

Filaments

Stigma

Style

ovary

IB Assessment Statement

Distinguish between pollination, fertilization, and seed dispersal.





9.3.2 Distinguish between pollination, fertilization and seed dispersal

• Pollination – pollen is transferred from anther to a stigma

• Fertilization- After pollination a zygote is formed by the fusion of a male gamete with a female gamete inside the plants ovule.

•Seed Dispersal – Ovaries develop into a fruit. The function of a fruit is to disperse seeds.

Pollination

Pollen grains contain the male gametes of the plant

They are picked up by a pollinator and transferred to another flower

Plants tend to specialise in pollinators

This ensures the pollen is delivered to same species of plant

Yellow archangel Lamiastrum galobdolon being pollinated by a bumble bee Bombus hortorum



Pollination

Small skipper Thymelicus flavus on marsh thistle Cirsium palustris© 2008 Paul Billiet ODWS


Pollination

The honey bee Apis melifera on marsh thistle Cirsium palustris© 2008 Paul Billiet ODWS


Pollination

Most species of flowering plants are hermaphroditic

Pollen from a flower could land on the stigma of the same flower or another flower on the same plant = self pollination

Pollen transferred from the anther on one flower to the stigma of another flower on a different plant = cross pollination



FertilisationPollination ≠ Fertilisation

The male gamete (the male nucleus) has to get to the egg cell

The egg cell lies in an ovule in an ovary at the centre of the plant

The pollen grain germinates on the stigma

It grows a pollen tube down the style

It male nuclei travel down the pollen tube to the ovule




The pollen grain germinates on the stigma

It grows a pollen tube down the style


Pollen grains (N)(male gametophyte)

Stigma

Fertilisation


The egg cell lies in an ovule in an ovary at the centre of the plant

.

Haploid cell(N)

Ovule

Ovary (2N)

Fertilisation


Pollen grows a pollen tube down the style


Pollen tubeEgg cell

Sperm

Polar nuclei

Embryo sac (N)(female gametophyte)

Fertilisation


The sperm moves from the pollen tube to combine with the egg of the ovule to forma zygote (seed).

Pollen tube

Embryo sac (N)(female gametophyte)

Egg cell

Sperm

Polar nuclei

Fertilisation


The sperm moves from the pollen tube to combine with the egg of the ovule to forma zygote (seed).

As the seed develops around the ovary will develop into a fruit. Fruit protects the seed

Endosperm(3N)

Zygote (2N)

Fertilisation

Fertilisation

Style

Stigma

Pollen grain

Ovule

Embryo sac

Pollen tubeOvary




9.3.3 Draw and label a diagram showing the external and internal structure of a named dicotyledonous seed. Know the following location and function of the following structures:

•Testa•Micorphyle•Embryo root•Embryo shoot• cotyledons


Seed Germiination

The seed is the means by which an embryo can be dispersed to distant locations.

It is a protective structure for the embryo.


Seed Structure

a) Testa protects the plant embryo and the cotyledon food stores

b) Radicle is the embryonic root

c) Plumule is the embryonic stem

d) Cotyledons contain food store for the seed

e) Micropyle is a hole in the testa ( from pollen tube fertilisation) through which water can enter the seed prior to germination

f) Scar is where the ovule was attached to the carpel wall.



LE 38-8a

Seed coat(Testa)

Embryo Shoots(plumule)

Radicle(Embryo

root) Cotyledons



9.3.3 Draw and label a diagram showing the external and internal structure of a named dicotyledonous seed. Know the following location and function of the following structures:

•Testa•Micorphyle•Embryo root•Embryo shoot• cotyledons


IB Assessment Statements

9.3.4.Explain the conditions needed for germinaton of a typical seed.


Seed Germination

Conditions for the germination of a typical seed.

Seeds require a combination of:

•Oxygen for aerobic respiration

•Water to metabolically activate the cells

•temperature for optimal function of enzymes




9.3.5 Outline the metabolic processes during seed germination of a starchy seed,


Metabolic processes during germination of a starchy seed.

The metabolic events of seed germination:

a) Water absorbed and the activation of cotyledon cells

b) Synthesis of gibberellin which is a plant growth substance. (Hormone is some text longer a term used to describe such compounds).

c) The gibberellin brings about the synthesis of the carbohydrase enzyme amylase



The metabolic events of seed germination:

d) Starch is hydrolysed to maltose before being absorbed by the embryonic plant

e) The maltose can be further hydrolysed to glucose for respiration on polymerised to cellulose for cell wall formation.




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Reproduction of flower plants Watch Video Below Copyright Pearson Prentice Hall