Examkin

Question

Difficulty: MediumSpermatophytes: Gymnosperms and Angiosperms

Spermatophytes are categorized into gymnosperms and angiosperms based on distinct anatomical and reproductive features. Match each structural or reproductive item on the left with its corresponding biological description on the right.

  • Microsporangiate coneMale cone in gymnosperms that produces microspores developing into pollen grains
  • Ovary / Carpel structureEncloses ovules in angiosperms and matures into a true fruit after fertilization
  • Triploid endosperm (3n3n)Nutritive tissue formed as a result of double fertilization in angiosperms
  • ArchegoniumMulticellular female gametangium present in gymnosperms but absent in angiosperms

Answer

Microsporangiate cone pairs with the male cone in gymnosperms that produces microspores; Ovary / Carpel structure pairs with the organ that encloses ovules and matures into a fruit in angiosperms; Triploid endosperm pairs with the nutritive tissue formed via double fertilization in angiosperms; Archegonium pairs with the multicellular female gametangium present in gymnosperms but absent in angiosperms.
Each feature correctly matches its structural and evolutionary definition: microsporangiate cones produce male pollen grains in gymnosperms; ovaries enclose ovules to form fruit in angiosperms; double fertilization yields 3n3n endosperm in angiosperms; and archegonia exist in gymnosperms but are absent in angiosperms.

Step-by-Step Solution

1
Identify male reproductive structures specific to gymnosperms.
Microsporangiate cones serve as male strobili that yield microspores forming pollen grains.
Gymnosperms lack flowers and organize sporangia into cones.
2
Distinguish between seed-enclosing structures in angiosperms and gymnosperms.
Angiosperms possess ovaries (carpels) that enclose ovules and develop into fruit, whereas gymnosperms bear exposed ovules.
The ovary is the defining hallmark of angiospermy.
3
Compare fertilization mechanisms and nutritive tissues in seed plants.
Double fertilization produces triploid (3n3n) endosperm in angiosperms, whereas gymnosperm nutritive tissue is haploid (nn).
In angiosperms, a second sperm fuses with polar nuclei to generate 3n3n endosperm.
4
Evaluate female gametangia presence across both divisions.
Archegonia are retained within gymnosperm ovules but are completely absent in the reduced female gametophyte of angiosperms.
Angiosperms evolved a highly reduced embryo sac consisting of 8 nuclei without discrete archegonia walls.

Key Concept

Anatomical and reproductive differences between Gymnosperms and Angiosperms
Estimated Time:1m 30s
Rate this question

Topics

Spermatophytes: Gymnosperms and Angiosperms

More questions from this topic