Transcript Section 6.2: Kingdom Plantae pgs. 169-181

Section 6.2:
Kingdom Plantae
pgs. 169-181
Four Groups of Plants
1.
2.
3.
4.
Mosses & relatives
Ferns & relatives
Cone-bearing plants
Flowering plants
1. Mosses & Relatives
(Non-Vascular Plants)
Three divisions of non-vascular plants:
1. Mosses (Bryophytes)
2. Hornworts (Anthocerophytes)
3. Liverworts (Hepatophytes)
1. Mosses & Relatives
(Non-Vascular Plants)
• Have no roots
• Instead have small root-like
structures called rhizoids.
• Grow in mats of low, tangled
vegetation that can hold water
like a sponge.
Mosses (Bryophytes)
• Common in moist, shaded areas.
• Sphagnum moss is valuable as it is highly
water absorbent and nutrient rich (peat
moss).
2. Ferns & Relatives
(Seedless Vascular Plants)
• Have vascular tissue.
• Grow taller and live in a wider range of
habitats compared to mosses.
• Ex. Whisk Fern, Club Mosses, Horsetails
Seed-Producing Vascular Plants
Made up of 2 groups that disperse
using seeds:
Cone-Bearing Plants (Gymnosperms)
Flowering Plants (Angiosperms)
Seeds enable plants to reproduce
sexually without water.
3. Cone-Bearing Plants
(Gymnosperms)
• They have roots, stems &
leaves.
• They have seeds exposed on
the surface of cones. Ex.
Conifers (cone-bearing)
• Female cones develop ovules in archegonia
that grow on the upper surface of each cone
scale.
• Male cones produce microspores that develop
into pollen grains (dispersed by wind)
• When pollen lands next to the archegonia, it
produces a pollen tube.
• Sperm passes along it to get to the egg.
4. Flowering Plants
(Angiosperms)
• Grow and develop seeds that are enclosed
within a fruit.
• Include trees, shrubs, grasses, etc…
4. Flowering Plants
(Angiosperms)
• Divided into two large classes
based on the number of seed
leaves on the embryo within the
seed:
1. Monocots: one seed leaf
(grasses, lilies, orchids, irises)
2. Dicots: two seed leaves (roses,
peas, cacti, daisies, maple trees)
Seed Leave in the Embryo
(Cotyledons)
Angiosperm Reproduction
• Female reproductive organ
is the pistil.
• During pollination, the
pollen grain grows an
extension called a pollen
tube, to carry sperm cells to
the ovule.
• The sperm & egg unite to
form a zygote which divides
to produce an embryo with
an immature root, stem &
one or two seed leaves.
• The wall of the ovule hardens
and becomes a protective
seed coat.
** Know figure 6.13 on page
176.
Flower Anatomy
Can you identify these parts?
Pollination Adaptations
• Most methods of
pollination involve
insects, birds, bats, etc.
• Color, shape & scent of
the flower helps the
pollinator recognize the
source of food.
Pollination
• Angiosperms can live nearly on every region
on Earth, but could not do so without the
presence of animals to help in pollination.
Self-Pollination
• Single plants often produce many flowers
which can create conditions for self-pollination.
• Self-pollination produces genetically identical
offspring.
Seed Structure
• The hard case of the seed allows the embryo
inside to survive adverse conditions such as
dry & hot conditions.
• Angiosperm seeds are further protected by
the fleshy walls of the ovary.
Videos
How Stuff Works – Pollination Video (1:48)
Angiosperms: The flowering plants (20 min)
Section 6.2:
Review Questions
• Do the handout called “Plant Reproduction”.
• Do the handout called “Table 2: Plants
Worksheet”.
• Do question #’s 1-9 on page 181.
Section 6.2
Answers
1.a) Name the four broad groups into which the
plant kingdom is divided.
1.
2.
3.
4.
Non-vascular (mosses)
Vascular non-seed bearing (ferns)
Vascular cone-bearing (gymnosperm)
Vascular flowering (angiosperm)
1. b) What key feature or features are the basis
for this grouping?
The key features are the presence or absence
of a vascular system & mode of reproduction.
2. What are the products of meiosis in the four
different groups of plants?
In ferns and mosses, meiosis produces
spores. In angiosperms and gymnosperms,
meiosis produces eggs & pollen.
3. How do bryophytes compare with plants in
the other three major groups?
Bryophytes are the mosses and their relatives
– simple non-vascular plants. They lack
vascular tissue and have no true roots, stems
or leaves.
4. Ferns are more diverse and widespread than
any other division of non-vascular and sporeproducing plants. What features of ferns
account for this?
Having a vascular system and a dominant
sporophyte generation enable ferns to be
more diverse and widespread.
5. For each pair of terms below, explain what
they have in common and how they differ.
a) carpel and stamen
Both are reproductive organs of flowering
plants; the carpel is the female organ, and
the stamen is the male organ.
5. b) flower and cone
Both are seed-bearing structures. Flowers
grow on flowering plants, and cones grow
on coniferous plants.
5. c) Angiosperm & gymnosperm
Both are large-seed bearing, vascular
divisions of the plant Kingdom.
Angiosperms are flowering plants with
seeds encased in fruits. Gymnosperms are
cone-bearing plants with exposed seeds.
d) Seed & spore
Both are reproductive structures. Seeds are mature
ovules that contain a sporophyte embryo
surrounded
by a protective coat. Spores are haploid
reproductive
cells that do not require fertilization.
6. What is the function of pollination? Explain why
pollination alone does not ensure successful
reproduction.
Pollination is the process by which pollen grains
from the anther reach the stigma of the pistil.
On its own, pollination does not ensure
successful reproduction because the pollen grain
must grow a pollen tube to reach the ovule.
7. a) Can a gamete develop into a complete
plant by itself, without fertilization? Explain.
Because a gamete is either a sperm or egg
cell, it cannot develop into a complete plant
by itself without being fertilized.
7. b) Can a spore develop into a complete plant
by itself, without fertilization? Explain.
A spore can develop into a complete plant by
itself because it does not require fertilization.
8. Explain why seeds can be referred to as
“plants in storage” while spores cannot.
Seeds contain all that is necessary for
producing a typical plant; the leaf, stem and
root are all found within the seed embryo.
Spores merely develop into sperm- and eggproducing gametophytes that form new
plants.
9. a) Explain the reproductive advantage of
preventing self-pollination.
Preventing self-pollination ensures variation
through sexual reproduction. The genetic
information of another individual is
incorporated into the zygote.
9. b) Explain the reproductive advantage of
permitting self-pollination.
Permitting self-pollination allows the plant to
complete the reproductive cycle and produce
offspring on its own. However, due to genetic
similarity, the offspring may be less likely to
survive changing environmental conditions.