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Transcript
Name :________________
Date:______
Read pages 286-287 , in addition to the section below
The Plant Kingdom-The Gymnosperms (about 1,000 different species)
Plants that have vascular tissue are divided into two groups: those that produce flowers
(angiosperms) and those that produce cones (gymnosperms). First we will learn about
the gymnosperms.
The word gymnosperm is derived from 2 Greek words:
gymnos = naked
sperma = seed
All gymnosperms make cones. Some cones contain pollen and some eventually contain
seeds. The seeds have a tough seed coat covering them. However, they are “naked”
because they are not enclosed in a fruit.
Three basic facts about gymnosperm plants that you MUST know are:
• seeds not enclosed in fruit
• do not make flowers
• Have male and female cones that are used in the reproductive process
Most gymnosperms are trees, but some are shrubs or vines. Most have layers of woody
xylem which give them great strength and height. Many gymnosperms supply softwood
lumber (angiosperms supply hardwood lumber).
There are 4 main divisions of gymnosperms
1) The Cycads2) The Ginkgo
3) The Desert Dwellers
4) The Conifers Ex: Pine, Fir, Spruce
 have needle like leaves and they are evergreens
 most produce male (smaller and in clusters) and female (larger and NOT in
clusters) cones on the same tree.
Sexual life of a pine tree ( a Conifer)
The entire process can take two (2) years!!
a) Preparation:
Female: Egg from ovule produces sticky fluid on the female cone.
Male:
Pollen grains with sperm develop and are released into the air.
b) WIND carries pollen to female cone and it lands on the sticky fluid on the female
cone. (called pollination)
c) Pollen tube grows to reach the egg at the base of the female cone. (can take
months)
d) Fertilization occurs when sperm from pollen finally swim (through the pollen
tube) to meet the egg in the female cone.
e) Zygote is now formed. Female Pine cones of Pine trees, mature, open and release
their seeds during the fall or winter months.
f) Once seeds are released they are carried away, eaten or buried by animals. May or
may not germinate.
Review and reinforcement
An acrostic. Use the definitions to fill in the blanks
G __________
A group of gymnosperm
Y __________
A group that lived many ________ago
M __________
Gymnosperms __________ cones
N__________ ______
Gymnosperm means _________ _________
O __________
The largest __________ is a conifer
S __________
Gymnosperms can be trees or ____________
P __________
This occurs when pollen lands on a female cone
E __________
Some cones ______________ contain seeds
R__________
Cones are used for _________________.
M __________
After fertilization, the ovule ___________ into a seed.
Questions:
1) Why are gymnosperms said to have “naked seeds”?
_____________________________________________________________________
2) The 2 Greek words that gymnosperm is derived from are:
_____________________________________________________________________
3) What is the function of the cones on gymnosperms?
_____________________________________________________________________
4) What are evergreens?
_____________________________________________________________________
5) What is pollination?
_____________________________________________________________________
6) What happens to the sperm after pollination?
_____________________________________________________________________
7) What is the purpose of a pollen tube?
_____________________________________________________________________
8) What happens during fertilization?
_____________________________________________________________________
9) After fertilization, what is now formed?
_____________________________________________________________________
10) What happens to the seeds after they are released?
_____________________________________________________________________