plants: grouped by characteristics vascular three main parts: roots, stems and leaves roots can be...
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Plants: Grouped by characteristics
Vascular Three main parts: roots, stems and leaves
Roots can be different sizes: Fibrous and tap roots
Storage roots; beets, carrots, sweet potatoes and turnips
Roots have different functions: anchoring the plant, taking in water and minerals, and store food.
Nonvascular Simple; most grow in moist places No vascular tissues.
Vascular Plants: Stems Function of stems
Support, transport of water & food Most stems grow upward Some stems grow sideward
Types of stems Green Woody
Transport of materials Xylem & phloem
Vascular Plants: Leaves Leaves come in variety of shapes and
sizes Leaves are arranged in different ways
Plants are classified by characteristics.
Plants that make seeds Plants that do not make seeds
Flowering Plants
Conifers Ferns Mosses
Plants reproduce differently
Reproduce – it means “to make more of the same kind”
a protective covering that surrounds the seed
anchor the plant in place and absorb water and other minerals from the soil.
carries water and food to the rest of the plant.
makes the plant's food.
makes seeds.
Basic Plant Structure
Some flowering plants are
dicot seed – a seed that has two seed leaves that contain stored food
monocot seed – a seed that has one seed leaf and stored food outside the seed leaf
Parts of a seed
Dicot
Monocot
Seed coat
Epicotyl
Cotyledons
Hypocotyl
Seed coat
Endosperm
Epicotyl
Hypocotyl
RadicleCotyledon
Seed Germination
Monocot Dicot
Hypogeous
Epigeous
Radicle
Leaf Morphology
Leaf Morphology
Structure: Leaf Types
Structure: Leaf Venation
Structure: Leaf Arrangement
Woody Plant Stem
Stern 2006
Woody Stem Structure
What are the critical parts of a tree?
Xylem (earlywood/latewood)
Bark
Cambium/Phloem
Wood Plant Stem
Stern 2006
ANGIOSPERMSThe flowering plants
Spring crocus Crocus vernus
Flower structure Flowers are reproductive structures The have evolved to send and receive
pollen from one flower to another This is process of pollination Flowers are developed from a series of
modified leaves These leaves are arranged in a rings
(whorls)
Flower structure
Dog rose Rosa canina
Structure of flowersFlowers are composed
of four whorls. From the outside in, they are:
• Calyx (sepals)
• Corolla (petals)
• Androecium (stamens)
• Gynoecium (pistils)
Flower Morphology
Flower structureStigma
Style
OvaryPetal
Sepal
Filament
Anther
Calyx (sepals)
Outermost whorl Usually green Protects developing
flower Physically Chemically
Made up of SEPALS Sepals free or not Calyx radially or
bilaterally symmetric
Corolla (petals)
Is usually colorful and showy;
Attracts pollinators Guides pollinators; Is composed of petals Petals may be united
or separate; Corolla may be
radially or bilaterally symmetric.
Androecium (stamens)
Is composed of stamens
Stamens have filaments and anthers
Pollen is produced in anthers
Stamens can be free or united
Gynoecium (pistils) Is composed of
pistils A pistil is composed
of an ovary, style, and stigma.
Styles may be separate, branched, or united
Pistils have a slide of their own – just wait
Structure: Flowers- missing parts Floral Parts Structure
Reproduction Sepals, Petals, Complete
Perfect Stamens, Pistil
Sepals, Stamens, Incomplete PerfectPistil
Sepals, Stamens Incomplete Imperfect
Structure- Compound Flower/ Sunflower
Structure- Flower- Compound Pistil/ Strawberry
Structure: Flower Parts
How Do Flowers Make Seeds and Fruits?
Ovary – the bottom part of the pistil in which seeds form
Ovule - the inner part of an ovary that contains an egg
embryo – tiny part of a seed that can grow into a new plant
How Seeds Form After fertilization the flower dries
up and petals fall off, leaving just the pistil and its ovary.
The top of the pistil falls off and the ovary gets larger as one or more seeds form inside it.
When the seeds are formed, the ovary dries up and the seeds fall out.
Corn, Beans, and Peas are seeds that we eat
How Fertilization Occurs When a pollen grain reaches a pistil, it
grows a thin tube to the ovary. Sperm from the pollen grain combines with an egg, and a seed forms.
Fertilization – the combination of sperm from a pollen grain with an egg to form a seed
How Pollination Occurs
Butterflies may carry pollen from the stamen of one flower to the pistil of the the same flower. Sometimes the butterfly may carry pollen from the stamen of one flower to the pistil of another flower of the same kind.
Pollination- the movement of pollen from a stamen to a pistil
Types of pollination Wind Animal Water
Bumble bee Bombus hortorum on red clover Trifolium pratense
Yorkshire fog grass Holcus lanatus
Animal pollination Usually insects Also other flying
animals e.g. hummingbirds or
fruit bats
Cerambycid beetle pollinating bramble Rubus fruticosus
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
Pollination
The honey bee Apis melifera on marsh thistle Cirsium palustris
Pollination Some flowers are
highly specialised to encourage only one type of insect
Fox glove flowers Digitalis purpurea
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
Fertilisation Pollination ≠ 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
Fertilisation
Style
StigmaPollen grain
Ovule
Embryo sac
Pollen tubeOvary
Fertilisation
Egg cell
Polar nuclei
Embryo sac
Micropyle
Fertilisation
Pollen grains of the daisy Bellis perennis
Fertilisation
Germinating pollen grains of blue bell, Hyacinthoides non-scripta
The double fertilisation
Pollen tube
Pollen tube entering micropyle
Male nucleus + egg cell
= zygote (2n)
Male nucleus + 2 polar nuclei = endosperm nucleus (3n)
OvuleNucellus
From flower to fruit
Marsh marigold Caltha palustris
Fruits and seed dispersalAnimal dispersal Strawberry Fragaria vesca
Wind dispersal Ragwort Senecio
Explosive dispersal Bird’s foot trefoil Lotus corniculatus
Animal dispersalWood avens Geum urbanum
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