Part I: Reproduction With Cones and Flowers

This section describes the reproductive structures of gymnosperms and angiosperms. It also explains how pollination and fertilization differ between angiosperms and gymnosperms.

Alternation of Generations

1. Circle the letter of each sentence that is true about alternation of generations in plants.

a. In all plants, the sporophyte generation is diploid.
b. The gametophyte in seed plants is hidden within the sporophyte plant.
c. The recognizable part of a seed-bearing plant is the gametophyte.
d. In all plants, the gametophyte generation is haploid.

2. An important trend in plant evolution is the reduction in the size of the.

3. Where are the gametophytes found in gymnosperms and angiosperms?

Life Cycle of Gymnosperms

4. Reproduction in gymnosperms takes place in .

5. Circle the letter of what produces cones in gymnosperms.

a. mature sporophyte c. pine trees
b. mature gametophyte d. pollen seeds

6. What kind of cone produces male gametophytes?

7. The male gametophytes of gymnosperms are called.

8. Circle the letter of each sentence that is true about seed cones.

a. They produce pollen grains.
b. They produce female gametophytes.
c. They have two ovules at the base of each scale.
d. They are generally much larger than pollen cones.

9. Is the following sentence true or false? Each mature female gametophyte contains hundreds of egg cells ready for fertilization.

10. How long does the gymnosperm life cycle typically take to complete?

11. In the gymnosperm life cycle, how do the pollen grains reach the female cones?

12. What ensures that pollen grains stay on the scales of a female cone?

13. A structure grown by a pollen grain that contains two sperm nuclei is called a(an).

14. What happens to the two sperm cells once the pollen tube reaches the female gametophyte?

15. Circle the letter of what a gymnosperm embryo can be called.

a. mature gametophyte c. mature sporophyte
b. new sporophyte d. new gametophyte

16. What are the three generations of the gymnosperm life cycle that are contained in a gymnosperm seed?

Structure of Flowers

17. What are the four kinds of specialized leaves that compose a flower?

Match the floral part with its description.

Floral Part      Descriprion

18. Sepals  a. Stalk with the stigma at the top
19. Petals  b. Structures where male gametophytes are produced
20. Stamen   c. Flower part that contains one or more ovules
21. Filament   d. Outermost, green floral parts
22. Anthers   e. Long, thin structure that supports an anther
23. Carpels   f. Innermost floral parts that produce female gametophytes
24. Ovary   g. Sticky, top portion of style
25. Style   h. Male structure made up of an anther and a filament
26. Stigma   i. Brightly colored parts just inside the sepals

27. Label the parts of the flower on the illustration.

28. What is a pistil?

29. What are the separate male and female flowers on a corn plant?

Life Cycle of Angiosperms

30. Where does reproduction in angiosperms take place?

31. Inside the anthers, each cell undergoes meiosis and produces haploid cells called.

32. In angiosperms, the pollen grain is the entire.

33. The female gametophyte of an angiosperm, contained within the ovary, is called the .

34. Circle the letter of each sentence that is true about the life cycle of angiosperms.

a. The cycle begins when the mature sporophyte produces flowers.
b. A pollen grain stops growing when it is released from the stigma.
c. The female gametophyte develops in the ovule.
d. The egg nucleus is one of the eight nuclei in the embryo sac.

Pollination

35. How are most gymnosperms pollinated?

36. How are most angiosperms pollinated?

37. What are three kinds of animals that pollinate angiosperms?

Fertilization in Angiosperms

38. What are the two distinct fertilizations that take place in angiosperms?

39. The food-rich tissue that nourishes a seedling as it grows is known as.

40. Why is fertilization in angiosperms known as double fertilization?

41. Use the information on pages 614 to 616 to complete the flowchart about the life cycle of angiosperms.

Inside the anthers, each cell undergoes to produce four haploid spore cells.

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Each spore cell becomes a(an) .

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The nucleus of each pollen grain produces two haploid.

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The pollen grain lands on a stigma and begins to grow a(an) that eventually reaches the ovary and enters the.

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One of the sperm nuclei fuses with the egg nucleus to produce a(an) , and the other sperm nuclei fuses with two other nuclei to form a cell that grows into the.