Biology 11
D7.3
Explain how gymnosperms are adapted for survival in a land environment with
respect to alternation of generations, needles, seeds, pollen, and vascular tissue.
Research
Summarize what you have learned so far and do some additional research to find out how
gymnosperms are adapted for survival on dry land. Use the following headings as a
guide:
Vascular tissue:
Seeds:
Pollen:
Needles:
Alternation of generations:
Answer Key
Laboratory Assignment
You may wish to refer to the illustrations of stomata (sg. stoma) on pages 503 and 504 of
Biology, 3rd ed. (Miller & Levine) while you do this lab work.
Using the compound microscope, examine a prepared slide of a pine needle in crosssection. Locate a sunken stoma. Make a careful pencil sketch of this structure on a piece
of white unlined paper. Label your drawing to the best of your ability. Answer the
following questions and hand them in to your teacher for marking, along with your
drawing.
1. What is the function of a plant's stomata?
2. What is the advantage to a pine in having the stoma located in sunken pits?
3. Label the guard cells in your sketch, if you have not done so already. What is their
function? How do they work? What disadvantage does the plant experience when
water is in short supply?
(© 2004. C.K. Robinson, Summerland Community Learning Centre, School District No. 67)