Science ProjectScience Projectonon

AngiospermsAngiosperms

For Academic year 2012-13For Academic year 2012-13

by Shakti Swarup Satpathyby Shakti Swarup Satpathy

Magnoliophyta

Fossil AngiospermsFossil Angiosperms Primitive fossils of 125-million-year-old Primitive fossils of 125-million-year-old

angiospermsangiosperms Display both derived and primitive traitsDisplay both derived and primitive traits

Carpel

Stamen

Archaefructus sinensis, a 125-million-year-old fossil.

(a)

Artist’s reconstruction of Archaefructus sinensis

(b)

5 cm

Angiosperm EvolutionAngiosperm Evolution

Clarifying the origin and diversification of Clarifying the origin and diversification of angiosperms.angiosperms. Poses fascinating challenges to evolutionary Poses fascinating challenges to evolutionary

biologists.biologists. Angiosperms originated at least 140 million Angiosperms originated at least 140 million

years ago.years ago. And during the late Mesozoic, the major branches of And during the late Mesozoic, the major branches of

the clade diverged from their common ancestor.the clade diverged from their common ancestor.

Angiosperm DiversityAngiosperm Diversity

The two main groups of angiosperms are- The two main groups of angiosperms are- monocots and dicotsmonocots and dicots Basal angiosperms are Basal angiosperms are less derived and less derived and include the flowering plants belonging to the include the flowering plants belonging to the

oldest lineages oldest lineages MagnolidsMagnolids

Share some traits with basal angiosperms but are more Share some traits with basal angiosperms but are more closely related to monocots and eudicotsclosely related to monocots and eudicots

Exploring Angiosperm DiversityExploring Angiosperm Diversity

Amborella trichopodaWater lily

Star anise (Illicium floridanum)

BASAL ANGIOSPERMS

HYPOTHETICAL TREE OF FLOWERING PLANTS

MAGNOLIIDS

Am

bo

rell

a

Wa

ter

lili

es

Sta

r an

ise

and

re

lati

ves

Ma

gn

oli

ids

Mo

no

co

ts

Eu

dic

ots

Southern magnolia (Magnoliagrandiflora)

Magnolia: Virginiana flower

Kindom: Plantae

Division: Magnoliophyta

Class: Magnoliopsida - DicotsClass: Liliopsida - Monocots

Class Magnoliposida

The dicotyledons

Class: Liliopsida

The monocotyledons

Characteristics of AngiospermsCharacteristics of Angiosperms

The key adaptations in the The key adaptations in the evolution of angiosperms are evolution of angiosperms are

flowers and fruits.flowers and fruits.

FlowersFlowers

A flower is an angiosperm A flower is an angiosperm structure specialized for sexual structure specialized for sexual

reproduction.reproduction.

Structure of flower

A flower is a specialized shoot with modified A flower is a specialized shoot with modified leavesleaves Sepals, which enclose the flower Sepals, which enclose the flower Petals, which are brightly colored and attract Petals, which are brightly colored and attract

pollinatorspollinators Stamens, which produce pollenStamens, which produce pollen Carpels, which produce ovulesCarpels, which produce ovules

Anther

Filament

Stigma

Style

Ovary

Carpel

Petal

ReceptacleOvule

Sepal

Stamen

stigma

style

ovary

ovule

megasporocyte

micropyle

The carpel

Megasporocyte(2N)

Megaspore(N)

meiosis

Megaspore(N)

Female gametophyte(N)

Mitosis and rearrangement

Female gametophyte contains the egg cell

Creation of microspores

microspore

microsporocyte

microsporocyte microsporemeiosis

Creation of microspores

Pollen grain

Generative cellTube cellnucleus

pollination

Tube nucleus

Generativenucleus

Pollen germination

Tube nucleus

sperm

sperm

Tube nucleus

MatureMale gametophyte

The Angiosperm Life CycleThe Angiosperm Life Cycle In the angiosperm life cycleIn the angiosperm life cycle

Double fertilization occurs when a pollen tube Double fertilization occurs when a pollen tube discharges two sperm into the female gametophyte discharges two sperm into the female gametophyte within an ovulewithin an ovule

One sperm fertilizes the egg, while the other One sperm fertilizes the egg, while the other combines with two nuclei in the center cell of the combines with two nuclei in the center cell of the female gametophyte and initiates development of female gametophyte and initiates development of food-storing endospermfood-storing endosperm

The endospermThe endosperm Nourishes the developing embryoNourishes the developing embryo

The reduced gametophytes of seed plants are The reduced gametophytes of seed plants are protected in ovules and pollen grainsprotected in ovules and pollen grains

In addition to seeds, the following are common In addition to seeds, the following are common to all seed plantsto all seed plants Reduced gametophytesReduced gametophytes HeterosporyHeterospory OvulesOvules PollenPollen

TheEndTheEnd

Thank You Thank You

Creation of Creation of Name: Shakti Swarup SatpathyName: Shakti Swarup Satpathy

Class: IXClass: IXRoll no.:10 Roll no.:10

School name: Metropolitan Central SchoolSchool name: Metropolitan Central SchoolFor academic Year 2012-13For academic Year 2012-13Subject teacher: Miss StellaSubject teacher: Miss Stella

Created on: 26.10.12Created on: 26.10.12Bibliography:Bibliography:

en.wikipedia.org/wiki/Flowering_plant en.wikipedia.org/wiki/Flowering_plant biology.clc.uc.edu/courses/bio106/angio.htmlbiology.clc.uc.edu/courses/bio106/angio.html

www.biology4kids.com/files/plants_www.biology4kids.com/files/plants_angiosperm.html .html