Download Characteristics of Seed Plants

Characteristics of Seed Plants
EQ: How do I describe the
function of leaves, stems, roots
and flowers?
Seed Plants
• Most common
type of plant on
Earth
• All seed plants
share 2
characteristics
– Vascular
tissue
– Use seeds to
reproduce
EQ: How do I
describe the
function of leaves,
stems, roots and
flowers?
Vascular Tissue
• Two types
– Phloem – vascular tissue through which food
moves
– Xylem – tissue through which water and
nutrient move
EQ: How do I describe the
function of leaves, stems,
roots and flowers?
Seeds
EQ: How do I describe the function of leaves,
stems, roots and flowers?
• Structures
that contain
a young
plant inside
a protective
covering
• Different
from
seedless
plants in that
they do not
need water
for sperm to
travel
Three parts to a Seed
• Embryo
• Stored food
• Seed coat
EQ: How do I describe the
function of leaves, stems,
roots and flowers?
EQ: How do I describe
the function of leaves,
stems, roots and
flowers?
Embryo
• Young plant that develops from the zygote
• Already has the beginnings of root, stem
and leaves
Cotyledons
• Food stored inside one or
two seed leaves
• Embryo uses food stored
in seed to help it continue
to grow
EQ: How do I describe the function of leaves,
stems, roots and flowers?
Seed Coat
• Outer covering of seed
• Acts like plastic wrap and keeps the seed
and its food from drying out
• Allows seed to remain dormant for a long
time
EQ: How do I
describe the
function of leaves,
stems, roots and
flowers?
Needs of Seeds
– Light
– Water
– Nutrients
EQ: How do I describe the function of
leaves, stems, roots and flowers?
Seed Dispersal
• Scattering of seeds
• Dispersed many ways
– Animals
• digestion
• fur or people’s clothing
– Water
– Wind
– Some plants shoot out their seeds
EQ: How do I describe the function of
leaves, stems, roots and flowers?
Germination
• Early growth stage of
the embryo
• Steps to germination
EQ: How do I describe the
function of leaves, stems,
roots and flowers?
– Seed absorbs water
from the environment
– Embryo uses stored
food to begin to grow
– Embryo’s roots grow
down, then leaves and
stem grow upward
Germination
• Seeds which are dispersed far away from
the parent have a better chance of survival
because it does not have to compete for
nutrients, light and water
EQ: How do I describe the
function of leaves, stems, roots
and flowers?
EQ: How do I describe the
function of leaves, stems,
roots and flowers?
Leaves
• Most numerous part to a plant
• Role – capture the sun’s energy and carry
out the food making process of
photosynthesis
Leaf Structure
• Bottom and top layers which
protect cells
• Leaf veins that contain the
xylem and phloem
• Stomata –
– underside of leaf has small pores
or openings
– Opens and closes to control the
amount of gas that enters and
leaves the leaf
EQ: How do I describe the
function of leaves, stems, roots
and flowers?
Leaf and Photosynthesis
• Top layer of
leaf contains
chloroplasts
• Chlorophyll in
the
chloroplasts
trap sun’s
energy
EQ: How do I describe the
function of leaves, stems,
roots and flowers?
Leaf and Photosynthesis
• Carbon Dioxide enters the leaf through the
stomata
• Water, which is absorbed by the plants
roots, travels up to plant through xylem
• Sugar and oxygen are produced from the
CO2 and H2O.
EQ: How do I describe the function of
leaves, stems, roots and flowers?
Leaf and Photosynthesis
• Oxygen exits leaf
through stomata
• Sugar enters the
phloem and then
travels throughout
the plant
EQ: How do I
describe the function
of leaves, stems,
roots and flowers?
Controlling Water Loss
• Transpiration –
process by which
water evaporates
from a plant’s leaves
• Plants slow down
transpiration by
closing the stomata
EQ: How do I describe the
function of leaves, stems,
roots and flowers?
Stems
• Two important
functions
– Carries substances
between roots and
leaves
– Supports plant so
leaves are exposed to
the sun
EQ: How do I describe the
function of leaves, stems,
roots and flowers?
Structure of a Stem
• Two types of
stems
– Herbaceous – soft
and flexible
– Woody-hard and
rigid
• Both types contain
phloem and xylem
EQ: How do I describe the
function of leaves, stems, roots
and flowers?
Woody Stems
EQ: How
do I
describe
the
function of
leaves,
stems,
roots and
flowers?
• Bark - added layer of protection
• Heartwood – inner layers for additional support
Layers of a Woody Stem
EQ: How do I describe the
function of leaves, stems, roots
and flowers?
1. Bark
2. Phloem
3. Cambium -cells that
produce new phloem
and xylem
4. Active xylem
5. Heartwood- inactive
xylem
6. Pith – center of stem,
stores food and water
in young trees
Annual Rings
• Represent one year in a
tree’s growth
• Made of xylem
– Light rings grow in spring
– Dark rings grow in
summer
• Two rings together
make one year’s growth
EQ: How do I describe the function of leaves,
stems, roots and flowers?
Roots
• Anchor plants
• Absorb water and nutrients
EQ: How do I
describe the
function of leaves,
stems, roots and
flowers?
Types of Roots
• 2 types
EQ: How do I
describe the
function of
leaves, stems,
roots and
flowers?
– Taproot – long thick root with thin roots
branching off – carrot, radish, dandelion,
cactus
– Fibrous- several main roots that branch
repeatedly – lawn, corn, trees
Structure of Root
• Root cap – contains dead cells, protects
root from injury
• Dividing cells – cause root to lengthen
• Root hairs – grow out of root surface –
increases the surface area of the roots
• Cambium
• Vascular tissue in center
EQ: How do I describe the function of
leaves, stems, roots and flowers?
Class Work and Homework
• Fill In
– What did I learn
– Confused
– Say
EQ: How do I
describe the
function of
leaves, stems,
roots and
flowers?