Table of contents

1. Introduction to Biology2h 42m
2. Chemistry3h 37m
3. Water1h 26m
4. Biomolecules2h 23m
5. Cell Components2h 26m
6. The Membrane2h 31m
7. Energy and Metabolism2h 0m
8. Respiration2h 40m
9. Photosynthesis2h 49m
10. Cell Signaling59m
11. Cell Division2h 47m
12. Meiosis2h 0m
13. Mendelian Genetics4h 44m
14. DNA Synthesis2h 27m
15. Gene Expression3h 6m
16. Regulation of Expression3h 31m
17. Viruses37m
- Viruses
  37m
18. Biotechnology2h 58m
19. Genomics17m
- Genomes
  17m
20. Development1h 5m
21. Evolution3h 1m
22. Evolution of Populations3h 53m
23. Speciation1h 37m
24. History of Life on Earth2h 6m
25. Phylogeny2h 31m
26. Prokaryotes4h 59m
27. Protists1h 12m
28. Plants1h 22m
29. Fungi36m
- Fungi
  19m
- Fungi Reproduction
  17m
30. Overview of Animals34m
- Overview of Animals
  34m
31. Invertebrates1h 2m
32. Vertebrates50m
33. Plant Anatomy1h 3m
34. Vascular Plant Transport1h 2m
- Water Potential
  1h 2m
35. Soil37m
- Soil and Nutrients
  20m
- Nitrogen Fixation
  16m
36. Plant Reproduction47m
- Flowers
  33m
- Seeds
  14m
37. Plant Sensation and Response1h 9m
38. Animal Form and Function1h 19m
39. Digestive System1h 10m
- Digestion
  1h 3m
- Blood Sugar Homeostasis
  7m
40. Circulatory System1h 49m
41. Immune System1h 12m
42. Osmoregulation and Excretion50m
- Osmoregulation and Excretion
  50m
43. Endocrine System1h 4m
- Endocrine System
  1h 4m
44. Animal Reproduction1h 2m
- Animal Reproduction
  1h 2m
45. Nervous System1h 55m
- Neurons and Action Potentials
  1h 8m
- Central and Peripheral Nervous System
  46m
46. Sensory Systems46m
- Sensory System
  46m
47. Muscle Systems23m
- Musculoskeletal System
  23m
48. Ecology3h 11m
49. Animal Behavior28m
- Animal Behavior
  28m
50. Population Ecology3h 41m
51. Community Ecology2h 46m
52. Ecosystems2h 36m
53. Conservation Biology24m
- Conservation Biology
  24m

28. Plants

Seed Plants

General Biology

28. Plants

Seed Plants

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3:08 minutes

Problem 6

Textbook Question

The diploid sporophyte stage is dominant in the life cycles of all of the following except
a. A pine tree.
b. A rose bush.
c. A fern.
d. A moss.

Verified step by step guidance

Understand the concept of alternation of generations: In plants, the life cycle alternates between a diploid sporophyte stage and a haploid gametophyte stage. The dominance of either stage varies among plant groups.

Recall that in most vascular plants, such as pine trees, rose bushes, and ferns, the diploid sporophyte stage is dominant. This means the sporophyte is the larger, more visible, and longer-lived stage of the life cycle.

Recognize that mosses are nonvascular plants, and in their life cycle, the haploid gametophyte stage is dominant. The gametophyte is the green, photosynthetic structure that is most visible in mosses.

Compare the life cycles of the given plants: Pine trees, rose bushes, and ferns are vascular plants with dominant sporophyte stages, while mosses are nonvascular plants with dominant gametophyte stages.

Conclude that the correct answer is moss, as it is the exception where the diploid sporophyte stage is not dominant in its life cycle.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Sporophyte and Gametophyte Stages

In the life cycles of plants, the sporophyte is the diploid stage that produces spores through meiosis, while the gametophyte is the haploid stage that produces gametes. In most vascular plants, including pines and roses, the sporophyte is the dominant stage, whereas in non-vascular plants like mosses, the gametophyte is more prominent.

Dominance of Sporophyte in Plant Groups

Different plant groups exhibit varying dominance of the sporophyte or gametophyte stages. In angiosperms (like roses) and gymnosperms (like pines), the sporophyte is the main form, while in bryophytes (like mosses), the gametophyte is the dominant form, highlighting the evolutionary adaptations of these groups.

Examples of Plant Life Cycles

Understanding specific examples of plant life cycles helps clarify the dominance of sporophyte or gametophyte stages. For instance, ferns have a prominent sporophyte stage, while mosses primarily exhibit a gametophyte stage, which is crucial for answering questions about plant classification and life cycle characteristics.