Please enable JavaScript.
Coggle requires JavaScript to display documents.
LIFE CYCLE IN ANGIOSPERMS (STAGES OF FLOWER LIFE CYCLE (Plant Growth (:<…
LIFE CYCLE IN ANGIOSPERMS
VEGETATIVE DEVELOPMENT
What Is Meristem?
:<3:
Vegetative
Plant maintain its vegetative growth pattern until apical meristem change
This change causes vegetative meristem alter to inflorescence
Produce all leaves
:<3:
Inflorescence
Produce small leaves before it produces floral meristem
Factors Influencing Flowering
:<3:
Photoperiod
Flower only when day length rises is known as long day plants
Flower only when day length drops is known as short day plants
Flowering does not depend on day length is day neutral
:<3:
Temperature
Also known as vernalization stage
Vernalization is a method of inducing early flowering at low temperature
Some plants require vernalization before correct photoperiod is required to trigger flowering
Flower Identity
:<3:
Sepals (whorl 1)
Gene A
:<3:
Petals (whorl 2)
Combination of Gene A & B
:<3:
Stamens (whorl 3)
Combination of Gene B & C
:<3:
Carpels (whorl 4)
Gene C
REPRODUCTIVE DEVELOPMENT
How Do Flowers Develop?
:<3:
Calyx
Consists of sepals
Outer series is green and leaf-like, functions to protect the
flower especially the bud
:<3:
Corolla
Consists of petals
Originated from modified sepals
Inner series (corolla of petals) functions in attracting insect
Attraction involves colour, scent and also nectar
:<3:
Stamen & Androecium
A male structure
Consists of a long filament with an ather at tip
:<3:C
arpels & Gynoecium
Consists of stigma, style and ovary
Once ovary is fertilized, carpel develop into a fruit
:<3:
Stigma & Style
Stigma is place where pollen lands and germinates its pollen tube
Style functions to connect the stigma from ovary
:<3:
Ovary
Contain one or more ovules
One ovule will develop into a seed
Variation In Flowers
:<3:
Perfect Flowers
Have both gynoecium & androecium (monoecious)
:<3:
Imperfect Flowers
Have stamens or carpels but not both (dioecious)
:<3:
Complete Flowers
Have all 4 whorls (monoecious)
:<3:
Incomplete Flowers
Lack one or more flower parts (monoecious or dioecious)
STAGES OF FLOWER LIFE CYCLE
Seed Dispersal
:<3:
Ways of Spread
Scattered by the wind
Stuck in animals fur
Depend on water
Pollination
:<3:
Cross Pollination
Flowers that can self-pollinate benefit from being fertilized by pollen from different plant
:<3:
Pollinators
Carry pollen from male flower part to female parts
Reproduction
:<3:
Flower
Sexually reproductive part of plant
:<3:
Pollen
Once trapped, it it goes to ovary where eggs waiting to be fertilized
:<3:
Ovary
Fertilized egg become seeds. Ovary ripens and becomes fruit
Plant Growth
:<3:
Leaves Emerge
Process of photosynthesis start
:<3:
Plants Contain Chloroplasts In Leaves
Convert the energy from sunlight, CO2 and H2O into sugars
:<3:
Root System
Anchoring plant into the ground & growing root hair which help to absorb water and nutrients
:<3:
Stem
Grows longer & transports water and food between root & leaves
:<3:
Leaves
Grow from the top of stem
:<3:
Bud
Later, flower buds develop
Seed Development
:<3:
Dicot
Have 2 cotyledons
Store food for the plant
:<3:
Monocot
Have only 1 cotyledon
Seed Germination
:<3:
Epigeal
Cotyledons above the ground
:<3:
Hypogeal
Cotyledons remain in the soil
GAMETE PRODUCTION IN ANGIOSPERM
Pollen
Outer wall (exine) composed of resistant material provided by both tapetum
Inner wall (intine) produced by the microspore
Tube cell contains a generative cell
Generative cell divides to produce 2 sperms
1 of the 2 sperm will fuse with egg cell to produce next sporophyte generation
2nd sperm will contribute to the formation of endosperm
Ovary
Carpel give rise to female gametophyte
Carpel consists of stigma, style & ovary
Ovary wall will develop into fruit
Within ovary, there are one or more ovules attached by placenta to ovary wall
Fully developed ovules are seeds
PHASES OF PLANT LIFE CYCLE
Haploid Stage
Microspore develop into male gametophyte
Megaspore develop into female gametophyte
Diploid Stage
Starts when an egg has been fertilized by sperm
In angiosperms, there is double fertilization
One of these haploid sperm cells fertilizes the haploid egg, produce diploid embryo
Sporophyte Generation
:<3:
Microspore
Develop in pollen grain in anther of stamen
Will develop into male gametophyte (pollen grain)
:<3:
Megaspore
Develop in megasporangium
Will develop into female gametophyte (embryo sac)
Gametophyte Generation
:<3:
Female
Develop in ovule within an ovary
1 egg, 2 synergids (micropylar end)
2 polar nuclei (center)
3 antipodal cell (chalazal end)
:<3:
Male
Develop within anther
Singular, nucleus
Germ nucleus & tube nucleus