Download Plant Parts and Functions

Plant Types/
Parts and Functions
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.
Two Types of Plants
• Angiosperms are fruit or
flower bearing.
• Gymnosperms are naked
seeds and cone bearing.
Angiosperms
– Two Groups:
Monocots
and
Dicots
Parts of The Plant
• Roots
• Leaves
• Stem
• Flower
• Seed
Image found at: www.webinstituteforteachers.org
Roots
• 2 Types of
Root Systems
– Taproot
– Fibrous
System
Image found at: http://www.puc.edu
Roots
Taproot System
Primary roots grow
down from the stem
with some
secondary roots
forming
Image found at: http://www.arboretum.fullerton.edu
Roots
Fibrous Root
System
Small lateral
roots that
spread out just
below the soil
surface
Image found at: www.wildmanstevebrill.com
Can you identify these root
types?
Root Functions
Roots have 4 primary functions
• Absorption of water and nutrients
– performed by root hairs
• Transportation of water and
nutrients to stem
• Anchor plant to maintain stability
• Store food and water
Parts of the Root
• Epidermis
– Outermost layer of cells, like the skin of the
root
• Cortex
– Tissue inside epidermis that stores starch
and other substances for the growth of the
root
Parts of the Root
• Root Cap
– Provides protection for
the root tip
• Root Hairs
– Site of absorption
Image found at: www.cactus-art.biz
• Vascular Tissue
– Within cortex, contains
cells that transport
water, nutrients, and
minerals to all parts of
the plant
Image found at: www.bio.psu.edu
Important Functions of
Leaves
• Photosynthesis
– Process that plants use to produce
their food
– 6CO2 + 6H2O C6H12O6 + 6O2
• Transpiration
– Loss of water and exchange of carbon
dioxide
Leaf Parts
• Blade
– Main body of leaf
• Petiole
– Attaches blade to
stem
• Midrib
– Large central vein
Image found at: www.yourdictionary.com
Leaf Parts
• Apex
– Tip of leaf
• Base
– Attaches to petiole – if petiole is absent, attaches directly
to stem
• Margin
– Edge of leaf
• Epidermis
– “Skin” of leaf - responsible for gas exchange
• Stomata
– Outside layer of leaf opening in epidermis where gas and
water exchange
• Mesophyll
– Middle layer of leaf where photosynthesis occurs
Functions of the Stem
• Transport water
and nutrients from
roots to leaves
• Supports leaves,
fruit, and flowers
• Food storage
Image found at: www.karencarr.com
Parts of the Stem
• Node
– Areas where side branches
and leaves develop
• Internode
– Area between nodes
• Xylem
– Carries nutrients up
• Phloem
– Carries nutrients down
• Pith
– Stores food
Image found at: www.ext.colostate.edu
Flower Function
Sexual Reproduction!!!!
• Flowers are pollinated by:
– Wind
– Insects
– Birds
Flower Parts
• Pistil
– Female part of
plant
– Containing:
• Stigma
• Style
• Ovary
Image found at: www.howe.k12.ok.us
Flower Parts
• Stamen
– Male reproductive
part
– Contains
• Anther
• Filament
Image found at: www.botanyworld.com
Flower Parts
• Petals
– Highly colored part
of the flower, may
contain perfume
and/or nectar
glands
• Sepals
– Small green
structures on the
base of a flower
that protect the
flower bud
Image found at: http://biology.clc.uc.edu
Parts of the Seed
• Embryo
– Growing part of seed containing:
• Plumule – “Shoot”
• Hypocotyl – Stem
• Radical – “Root”
• Endosperm
– Tissue that provides nutrition for the developing seed
• Cotyledon
– Food Storage
• Seed Coat
– Protective outer covering of the seed
Parts of the Seed
Image found at: www.puc.edu
Pollination
• Flowering plants
use the wind,
insects, bats, birds
and mammals to
transfer pollen
from the male
(stamen) part of
the flower to the
female (stigma)
part of the flower.
Pollination
• A flower is
pollinated when a
pollen grain lands
on its stigma.
• Each carpel grows
into a fruit which
contains the seeds.
Fertilisation
• Pollen grains germinate
on the stigma, growing
down the style to
reach an ovule.
• Fertilised ovules
develop into seeds.
• The carpel enlarges to
form the flesh of the
fruit and to protect
the ovary.
Wind pollination
• Some flowers, such as
grasses, do not have
brightly coloured
petals and nectar to
attract insects.
• They do have stamens
and carpels.
• These flowers are
pollinated by the wind.
Seed dispersal
Seeds are dispersed
in many different
ways:
• Wind
• Explosion
• Water
• Animals
• Birds
• Scatter
How birds and animals help
seed dispersal
• Some seeds are
hidden in the
ground as a winter
store.
• Some fruits have
hooks on them and
cling to fur or
clothes.
How birds and animals help
seed dispersal
• Birds and animals
eat the fruits and
excrete the seeds
away from the
parent plant.
Physical Adaptations Allowing
Plants to Survive on Land
• Cuticle – waxy covering of leaf for
water loss protection
• Spores and Seeds – reproductive cell
protection
• Tissue for absorbing and transporting
materials
• Spines and needles making ingestion
difficult.
• Storing water in stem as a cactus does.
Cuticle
Waxy coating preventing water
loss
Seeds
Embryo surrounded by a
protective coating
Moss (Spores)
Haploid reproductive cell
surrounded by a hard outer wall
Foxglove plant produces a
chemical affecting the heart
Poison Ivy
Chemical Adaptations
Allowing Plants to Survive
• Chemicals that are toxic and can kill
organisms eating them
– Foul odor
– Bitter taste
– Toxicity