Download Plant Life Cycles - Riverdale Middle School

Plant Structures – Review and Reinforce
pg. 83
1.
What are the functions of roots? Anchor a plant in
the ground, absorb water and minerals from the soil,
and sometimes store food.
2. Describe the two types of root systems. Taproot
System – a long thick, main root with many smaller
roots branching off (carrots, dandelions); Fibrous Root
System – thin fibrous roots that form a tangled
mass and take the soil with them when they are
pulled (lawn grass, corn)
3.
How do root hairs and vascular tissue help a plant
survive? Root hairs enter the spaces between soil
particles and absorb water and minerals. They also
help anchor the plant. Vascular tissue (xylem and
phloem) transport materials away from root, leaves
Plant Structures – Review and Reinforce
4.
pg. 83
What are the functions of stems? Carries substances
between the plant’s roots and leaves. Provides
support for the plant and holds up the leaves so they
are exposed to the sun. Some stems store food.
5. How are herbaceous stems and woody stems alike?
How are they different? They both carry substances
between roots and leaves, provide support, hold
leaves up to the sun. Woody stems contain wood, are
hard and rigid, many layers of tissue, bark and rings;
Herbaceous stems contain no wood and are often
green, soft and
flexible.
6.
Plant Structures – Review and Reinforce
pg. 83
What are the functions of xylem and phloem? xylem
– transports water and minerals through the stems
and leaves; phloem – transports food
manufactured in the leaves
7. What do annual rings in a tree reveal about its
history? They represent a tree’s yearly growth (made
of xylem). Xylem cells that form in spring – large, have
thin walls because they grow rapidly, wide light brown
ring. Xylem cells that form in summer – small, thick walls,
grow slow. One pair of light and dark rings represents
one year’s growth. Wide rings mean lots of rainfall.
8. What are the functions of leaves? They capture the
sun’s energy (chloroplast), carry out photosynthesis,
contain stomata which are small pores that control the
movement of gases in and out of the cell
9. How do stomata contribute to photosynthesis? They
open to let in carbon dioxide and allow water vapor
and oxygen to leave. They close to conserve water.
10.
What is transpiration? The process by which water
evaporates from a plant’s leaves.
11. What are the three parts of a seed? Embryo – young
plant inside the seed, stored food – embryo uses stored
food until it can make its own, seed coat – keeps the
embryo and its food from drying out
(cotyledons- seed leaves)
12.
Describe two ways seeds can be dispersed. Wind,
water, ejection, animals, humans
13. What is germination? After the seed is dispersed, the
embryo begins to grow again and pushes out the
seed. Begins when the seed absorbs water, then
embryo uses stored food to grow, roots grown
downward and leaves grow upward
14.
What is the function of flowers? Reproduction – a
flower is the reproductive structure of an angiosperm
pg. 85
Parts of a Flower
petals
STAMEN
anther
filament
sepal
receptacle
PISTIL
stigma
style
ovary
Parts of a Flower Vocabulary
pg. 84
1. Anther – part of the stamem (male part) that produces
pollen
2. Filament – part of the stamen (male part), the thin stalk
3. Ovary – (female part) protects the seeds as they develop
and contains one or more ovules
4. Petal- colorful, leaf-like structures that attract pollinators
with their color and scent
5. Pistil - the female reproductive parts, found in the center
of most flowers
6. Receptacle - part of a flower stalk where the parts of the
flower are attached
7. Sepal – the small, leaf-like parts that protect the
developing flower
8. Stamen – the male reproductive parts
9. Stigma – the sticky tip of the pistil (female part)
10.Style – slender tube connects the stigma to the
ovary(female part)
PLANT REPRODUCTION
WHAT ARE THE STAGES OF A PLANT’S
LIFE CYCLE?
Pg. 89
• Plants have complex life cycles that include two
different stages, the sporophyte stage and the
gametophyte stage.
• In the sporophyte stage, the plant produces spores
or seeds which can grow into new organisms.
• The spore or seed develops into a gametophyte.
• In the gametophyte stage, the plant produces two
kinds of sex cells: sperm cells and egg cells.
HOW DO PLANTS REPRODUCE?
• All plants undergo sexual reproduction that involves
fertilization. Fertilization occurs when a sperm cell
unites with an egg cell. The fertilized egg is called a
zygote.
• Many plants can also undergo asexual
reproduction. New plants can grow from the roots,
stems, or leaves of a parent plant.
NON-VASCULAR AND SEEDLESS
VASCULAR PLANTS
• Examples of nonvascular plants are mosses, liverworts, and
hornworts.
• Examples of seedless vascular plants are ferns, whisk ferns, club
mosses, and horsetails.
• Need to grow in moist environments.
• Release spores into their surroundings where they grow into
gametophytes.
• The gametophytes produce egg cells and sperm cells.
• In order for fertilization to occur, there must be enough water
available for the sperm to swim toward the egg.
LIFE CYCLE OF A FERN
Pg. 88
GYMNOSPERM LIFE CYCLE
(NON-FLOWERING PLANTS)
Pg. 90
1. CONE PRODUCTION
Pg. 91
• Most gymnosperms have reproductive structures
called cones. The cones are covered with scales.
• They produce two types of cones: male cones and
female cones.
• Some gymnosperms produce male cones or female
cones only.
• A few gymnosperms produce no cones.
2. POLLEN PRODUCTION AND OVULE
DEVELOPMENT
Pollen
• Pollen is produced by the male cones.
• Pollen contain cells that will mature into sperm cells.
Ovule
• The ovule is a structure that contains an egg cell.
• It is located at the base of each scale in the female
cone.
• The ovule later develops into the seed.
3. EGG PRODUCTION
• Two eggs cells form inside each ovule on the
female cone.
4. POLLINATION
• Pollination is the transfer of pollen from the male
reproductive structure to the female reproductive
structure.
• In gymnosperms, wind often carries the pollen from
a male cone to a female cone.
• Some pollen grains become trapped in a sticky
substance made by the ovule.
5. FERTILIZATION
• The ovule closes and seals in the pollen. The scale
also closes.
• A pollen grain makes a tube that grows into the
ovule.
• A sperm cell moves through the tube and fertilizes
the egg cell.
6. SEED DEVELOPMENT
• The ovule develops into a seed.
• The fertilized egg becomes the seed’s embryo.
• Other parts of the ovule develop into the seed coat
and the seed’s stored food.
7. SEED DISPERSAL
• When the seeds are mature, the scales open.
• The wind shakes the seeds out of the cone and
carries them away.
• Only a few seeds will land in suitable places and
grow into new plants.
ANGIOSPERM LIFE CYCLE
(FLOWERING PLANTS)
Pg. 92
1. FLOWER PRODUCTION
Pg. 93
• Angiosperms have a reproductive structure called
flowers.
• The male part of the flower is called the stamen
(anther and filament) and female part of the flower
is called the pistil (stigma, style, and ovary).
2. POLLEN PRODUCTION AND EGG
DEVELOPMENT
Pollen
• Pollen grains are produced in the anther.
• Pollen contains sperm cells.
Eggs
• Inside the ovary, an egg cell is produced in each
ovule.
3. POLLINATION
• A flower is pollinated when a grain of pollen falls on
the stigma.
• Some angiosperms are pollinated by the wind, but
most rely on other organisms.
4. FERTILIZATION
• The pollen grain produces a pollen tube that grows
into the ovule. A sperm cell moves through the
pollen tube and fertilizes the egg cell.
5. SEED DEVELOPMENT
• The ovule develops into a seed.
• The fertilized egg becomes the seed’s embryo.
6. FRUIT DEVELOPMENT
• The ovary develops into a fruit.
• A fruit is the ripened ovary and other structures that
enclose one or more seeds.
7. SEED DISPERSAL
• Fruits are the means by which angiosperm seeds
are dispersed.
• Animals that eat the fruit help to disperse their seeds
by depositing them in new areas.