Transcript Ch. 24 Plant Book Notesx

 Plants
life cycles have two alternating
phases known as alternation of
generations:
1.
2.
A diploid (2N) phase known as the sporophyte
(spore producing plant).
A haploid (N) phase known as the gametophyte
(gamete producing plant)
 Mosses
and ferns
require water to
reproduce. Seed
plants can
reproduce without
water.
Reproduction Before Angiosperms
– Bryophytes & Seedless Vascular
• Reproduce
using spores.
• Both require
water for
fertilization
(to get sperm
to egg).
Up until Gymnosperms, all land
plants still required water to get
sperm to egg, and they all
reproduced using single cells
without any real protection…they
were called spores.
But with the Gymnosperms new
reproductive structures evolved
which made them much more
successful on the land.
These were Pollen and Seeds.
 Reproduction
occurs in the Cones
 Male cone (pollen cone) —pollen
grains
 Female cone (seed cone) —ovules
 Pollen released into the air
 Fertilization occurs when the pollen
grain lands near an ovule  pollen
tube forms
Dominant
Stage 
•Flowers are reproductive organs :
composed of four kinds of specialized
leaves:
1. Petals
2. Sepals
3. Stamens
4. Carpels (also called Pistils)
Petals – Brightly colored structure just
inside the sepals; attracts insects and other
pollinators to a flower.
Sepals – Outermost circle of flower parts
that encloses a bud before it opens and
protects the flower while it is developing.
Male Parts of a Flower
• Stamen – Male part of the flower; Made up of
the anther and filament
• Anther – Produces pollen containing sperm
• Filament – Supports/Hold ups the anther
(thread like part)
Female Parts of a Flower
• Pistil (Carpal) – Female
part of the flower;
Innermost part of the
flower that produces the
female gametophyte
• The pistil is composed of the following structures:
1. Stigma- Sticky portion located at the top of the style
where pollen frequently lands
2. Broad base forms an ovary, which contains one or
more ovules (contains eggs inside)
3. The diameter of the carpel narrows into a stalk called a
style.
Complete Flower – Has all
four organs
Incomplete Flower (or
Imperfect Flower) – Lacks
one or more organs
Reproduction in Flowers
Similar to Gymnosperms Since:
1. Both produce seeds
2. Gametophytes are within the body
of the sporophyte.
POLLINATION
Pollination – Transfer of pollen from the
stamen to the pistil.
Methods of Pollination:
1. Wind
2. Animals (most are
pollinated by animals)
Pollination Adaptations That Attract Animals:
1. Nectar
2. Petal Color
3. Scent
TYPES OF POLLINATION
Self-Pollination – Stigma receives pollen
from the same plant.
Cross-Pollination –
Pollen from one plant is
carried to the stigma of
another plant.
-Must be same type of
plant.
-Allows for exchange of
genetic material
FRUITS
The (fertilized) ovary develops
into the fruit, which can be
dry or fleshy.
Fruits protect the seeds and
aid in dispersal.
Dry
Examples: Nuts and Grains
Fleshy
Examples: Oranges, Peaches,
Tomatoes, Squash

Vegetative Reproduction – reproduction of new
plants (by mitosis) from horizontal stems, from
plantlets, and from underground roots.
A spider plant (above) produces plantlets at
the tips of elongated stems  plantlet
reaches soil  grows into new plant
A strawberry
plant (left)
produces
horizontal
stems
(stolons)
The bamboo
plant (left)
has
underground
roots that
send up new
shoots

Parasitic plants extract nutrients and water
directly from its host’s tissues
After a (Cuscuta) Dodder attaches itself to a plant, it wraps itself
around it. If the host contains food beneficial to dodder, the
dodder produces haustoria that insert themselves into the
vascular system of the host. The original root of the dodder in the
soil then dies. The dodder can grow and attach itself to multiple
plants.
Mistletoe – takes
nutrients from the
trees