Download chapter 30 ap bio reading guide answers

AP Biology Reading Guide
Fred and Theresa Holtzclaw
Chapter 30: Plant Diversity II: The Evolution of Seed Plants
Name _______________________ Period ___________
Chapter 30: Plant Diversity II: The Evolution of Seed Plants
In this second chapter on the evolution of plants, it is important to know enough terminology to
understand the major evolutionary trends. As you work through this chapter, keep working to see the
big picture and try not to get lost by too many new terms. Be patient.
Concept 30.1 Seeds and pollen grains are key adaptations for life on land
1.
List five characteristics common to all seed plants.
Reduced gametophytes: gametophytes develop within the walls of spores and are retained within tissues of the parent sporophyte
Heterospory:
Ovules:
Pollen:
Seed Production:
2.
In seed plants, the evolutionary trend of gametophyte reduction continues. List four advantages
the plant gains by the miniaturization of the gametophyte.
1. Gametophytes can develop from spores retained within the sporangia of the parent 2. While
inside the parent sporophyte, they are protected from UV rays 3. They are protected from drying
out 4. They obtain nutrients from parent sporophytes
3.
Heterospory indicates that the plant produces two kinds of spores: megaspores and
microspores. Explain what each type of spore forms as it develops.
megaspore
microspore
4.
Megaspores give rise to female gametophytes
Microspores give rise to male gametophytes
ovule
gametophyte
Inside each ________________________,
a female ___________________________
develops
eggs
from a megaspore and produces one or more ______________.
5.
pollen grain
A microspore develops into a ____________________
that consists of a male
gametophyte
_________________
enclosed within the pollen wall.
A seed is a sporophyte embryo, along with its food supply, packaged in a protective coat
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AP Biology Reading Guide
Fred and Theresa Holtzclaw
6.
Chapter 30: Plant Diversity II: The Evolution of Seed Plants
What is the purpose of pollination?
Pollination is the transfer of pollen to the part of a seed
plant containing the ovule. Pollination is an important part
of seed plant reproduction
7.
What are two advantages of pollen over free-swimming sperm?
1. Pollen eliminates need for a film of water
2. Pollen can travel great distances via air or animals
8.
What are three advantages of seeds over spores?
1. They may remain dormant for days-years, until conditions are favorable for germination
2. They have a supply of stored food
3. They may be transported long distances by wind or animals
The ability of seeds to transfer sperm without water likely helped them colonize dryer habitats
9.
Using Figure 30.3 as a guide, label all parts of this figure. Then, below each of the three
drawings, explain what is occurring.
integument
immature ovulate cone
seed coat (from integument)
megaspor
angium
female
gametophyte
megaspore
spore wall
egg nucleus
emb
ryo
spore wall
food
supp
ly
discharged sperm nucleus pollen tube
male gametophyte
micropyle
pollen grain
cross section of an unfertilized pine ovule
megaspore develops into a female gametophyte, which produces
an agg. pollen grain enters through micropyle. The pollen grain
contains a male gametophyte which develops a pollen tube tht
then discharges sperm, thereby fertilizing the egg
fertilization initiates the transformation of the ovule
into a seed, which condists of sporophyte embryo, a
food supply, and a protective seed coat derived from
the integument. The megasporangium dries out and
collapses
Concept 30.2 Gymnosperms bear “naked” seeds, typically on cones
10.
Figure 30.5 shows the four phyla of gymnosperms. The phylum Coniferophyta will most likely
be the one with which you are most familiar. What are five examples of the Coniferophyta?
Douglas fir, common juniper,
european larch, Sequioa, wollemi
pine
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AP Biology Reading Guide
Fred and Theresa Holtzclaw
11.
Chapter 30: Plant Diversity II: The Evolution of Seed Plants
Understanding the life cycle of the pine should bring together the essential characteristics of
gymnosperms. Following Figure 30.6, label and give eight brief explanations of the important
features of the pine life cycle.
An ovulate cone scale has two
ovules, each containing a
megasporangium.
haploid
diploid
pollination occurs when a pollen grain
reaches the ovule. The pollen grain
germinates, forming a pollen tube
that slowly digests its way through
the megasporangium
ovulate cone
integument
pollen cone
Megasporocyte (2n)
Megasporangium (2n)
pollen grains (n)
meiosis
microsporangia
Seedling
meiosis
Surviving
microsporocytes
megaspore
(2n) inside
(n)
microsporangium.
These divide by
meiosis to produce
microspores which
turn into pollen
archegonia
grains
female gametophyte
Seeds on surface of ovulate scale
food reserves (gametophyte tissue (n)
embryo (new sporophyte) (2n)
While the pollen tube develops,
the megasporocyte undergoes
meiosis, producing four haploid
cells. One survives as a
megaspore
The megaspore develops
into a female gametophyte
that contains 2-3 archegonia,
each of which will form an
egg
seed coat discharged
sperm nucleus egg nucleus
pollen tube
fertilization
By the time the eggs are mature, sperm cells
Fertilization usually occurs more than a year after pollination. All eggs may be
fertilized, but usually only one zygote develops into an embryo. the ovule
becomes a seed, consisting of an embryo, food supply, and seed coat.
have developed into the pollen tube, which
extends to the female gemtophyte.
Fertilization occurs when sperm and egg
nuclei unite.
Study Hint: Continue to look for the big picture. Microspores will eventually produce pollen that will
contain sperm nuclei. Megaspores will eventually produce archegonia that will contain eggs. The
sperm and egg will unite to form a diploid embryo. The basics are the same as with any sexually
reproducing organism.
Concept 30.3 The reproductive adaptations of angiosperms include flowers and fruits
12.
Concerning seeds, what is the difference between gymnosperms and angiosperms?
In gymnosperms, seeds are exposed on sporophylls that form cones. In angiosperms, seeds are found in fruits, which are mature ovaries
13.
What is the specialized function of the flower?
In angiosperms, flowers facilitate sexual reproduction. They attract insects
or animals to transfer pollen from one flower to another, which makes their
pollination more directed than wind-dependent pollination of
gymnosperms.
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AP Biology Reading Guide
Fred and Theresa Holtzclaw
14.
Chapter 30: Plant Diversity II: The Evolution of Seed Plants
Label the ten structures on the flower diagram. Briefly give the function of each labeled part.
stigmas are sticky and receive pollen
Carpel (simple pistil) =
stigma + style + ovary
Stigma
stamens are microsporophylls — they produce
microspores that develop into pollen grains
containing male gametophytes
Stamen = Anther (tip) +
Anthers are sacs where pollen is produced Filament (little stem)
carpels are
megasporophylls: they
produce megaspores that
give rise to female
gametophytes. Seeds are
enclosed here. It is the key
structure that distinguises
gymnosperms from
angiosperms
Style
Ovary
Petal
Each ovule contains a female gametophyre.
When fertilized, an ovule develops into a seed.
Ovule
Petals attract pollinators
Receptacle
Sepal
sometimes flowers have more than
one carpel. A pistil refers to just a
single carpel.
sepals enclose
the flower before
it opens (like a
rosebud)
15.
ovary
A fruit consists of a mature __________________________________.
16.
List the two functions of fruits.
Protect seeds and aid in dispersal
17.
What is the difference between cross-pollination and self-pollination? What is the evolutionary
advantage of cross-pollination?
Self-pollination occurs when pollen from the anther of a plant transfers to the stigma of the
same plant. Cross-pollination occurs when the pollen from one plant transfers to the stigma
of another plant of the same species. Cross-pollination increases genetic diversity.
18.
What two events occur during double fertilization?
1. One sperm fertilizes the egg and forms a zygote 2. The other sperm fuses with the two nuclei in the
large central cell of the female gametophyte, producing a triploid cell called an endosperm. The endosperm
nourishes the zygote with food reserves and gives it a better chance at survival.
19.
In the space below, draw the essential features of the life cycle of an angiosperm. Use Figure
30.10 as a guide, but simplify the labeling to reflect only the most important terms. After
sketching and labeling, use your own phrasing to explain the process in seven concise steps.
See drawing on last page
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AP Biology Reading Guide
Fred and Theresa Holtzclaw
20.
Chapter 30: Plant Diversity II: The Evolution of Seed Plants
seed
After double fertilization, the ovule matures into the _____________
. The zygote develops
embryo
into the sporophyte ______________.
The embryo is nourished by a tissue called
endosperm
the________________.
21.
The two largest groups of angiosperms are monocots and eudicots. Flowering plants can often
be placed in one of these two categories by easy-to-observe characteristics. Label the following
portion of Figure 30.13 showing key differences between the two groups.
monocot
eudicot
one cotyledon
two cotyledons
parallel veins
net-like veins
vascular tissue scattered
fibrous root systems
pollen grain with 1 opening
floral organs in multiples of 3
vascular tissue arranged in rings
taproot usually present
pollen grain with 2 openings
floral organs in multiples of 4-5
Concept 30.4 Human welfare depends greatly on seed plants
22.
Explain the importance of seed plants to humans in the following areas:
food
80% of all calories consumed by humans come from 6 seed crops. angiosperms also feed livestock
wood
wood consists of tough-walled xylem cells. wood is primary source of fuel for much of the world. also important for paper
and fuel
medicines
in the usa, 25% of prescription drugs contain an active ingredient from plants
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AP Biology Reading Guide
Fred and Theresa Holtzclaw
23.
Chapter 30: Plant Diversity II: The Evolution of Seed Plants
Why should threats to plant diversity be taken seriously?
the loss of plant species is often accompanied by the loss of instinct and animal species, leading to collapses in
ecosystems and the vital services they provide. We are currently living in the 6th mass extinction.
Testing Your Knowledge: Self-Quiz Answers
Now you should be ready to test your knowledge. Place your answers here:
1.________ 2.________ 3.________ 4._________ 5. _________ 6.__________
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