Laboratory Investigation # 16
Gymnosperms
Description of the Lab
A major group of seed plants are the gymnosperms or cone bearing plants. The
Outline of Investigation
1. Pine Vegetative Features
A. Pine shoots
2. Pine Reproductive Cycle
2.1 Microgametophtye
A. Pollen (male) cone
B. Pinus pollen cone longitudinal section, prepared slide
C. Pinus germinating pollen, prepared slide
2.2 Megagametophyte and Fertilization
Laboratory Materials and Equipment for Student Use
Materials and Equipment
Per
Student
Per Pair of
Students
Per Lab
Group
Per
Room
Razor blade or scalpel
1
Dissecting scope
1
Prepared slides
Pinus stem (3-4 years old) x.s.
1
Pinus leaf x.s.
1
Pinus pollen cone l.s.
1
Preparation of laboratory Materials and Reagents
Four week prior to the lab
1. Start growing pine seedlings to give time for the development of the shoot.
Questions for Lab #16 Gynmopserms
Use the knowledge you acquired in this lab exercise, along with information from your
textbook, to answer the following questions.
1. What is the main difference between gymnosperms and flowering plants (or
angiosperms)?
2. What is an ovule and what is the relationship between a seed and an ovule?
Pinus mature seed (with seed coat)
1
3. To what is the nucellus equivalent?
4. What is the difference between the megagametophytes of gymnosperms and those of
seedless vascular plants?
In gymnosperms, the megagametophyte is entirely dependent on the sporophyte
5. What is the difference between the microgametophytes of gymnosperms and those of
seedless vascular plants?
The microgametophyte, it is highly reduced to only a few cells contained inside a
6. What is a pollen grain and what is pollination?
A pollen grain is the microgametophyte. Pollination is the transferring of sperm to
the egg.
7. To what are the pollen sacs equivalent?
8. Where does the seed coat come from and what is its ploidy?
9. How many of the generations of the life cycle are present in a complete pine seed?
10. What is the role of the megagametophyte tissue in the pine seed?
The megagametophyte is entirely dependent on the sporophyte. It develops from the
11. What is the function of cotyledons?