Biology, asked by channasagarchanna, 1 year ago

What are the three steps in the evolution of seed

Answers

Answered by krishna210398
1

Answer:

1. foundation of heterospory

2. improvement of integument layer for megasporangia which guard and supply

food.

3. retention of imatuare megaspores withinside the sporangia.

Explanation:

The evaluate may be divided into sections dealing with: (1) the improvement and anatomy of seeds; (2) the endosperm; (3) dormancy; (4) early seed-like systems and the transition to seeds; and (5) the evolution of seed size (mass). In many cases, a unique difference is made among angiosperm and gymnosperm seeds.Seeds and Pollen as an Evolutionary Adaptation to Dry Land

After fertilization of the egg, the diploid zygote produces an embryo so as to develop into the sporophyte whilst the seed germinates. Storage tissue to maintain increase of the embryo and a defensive coat supply seeds their shape.there are 3 steps for evolution of seed

1. foundation of heterospory

2. improvement of integument layer for megasporangia which guard and supply

food.

3. retention of imatuare megaspores withinside the sporangia.

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Answered by soniatiwari214
0

Answer:

  • Seeds and pollen, two essential drought-resilient and water-free reproductive mechanisms, set apart seed plants from other (seedless) vascular plants.
  • For the terrestrial colonization that the bryophytes and their progenitors started, both modifications were necessary.
  • The earliest unique seed plants date back to roughly 350 million years ago, according to fossils.
  • Gymnosperms first emerge in a trustworthy record during the Pennsylvanian epoch, or about 319 million years ago.
  • Pro gymnosperms, the earliest plants with bare seeds, appeared roughly 380 million years before gymnosperms.
  • Pro gymnosperms were a transitional class of plants that resembled conifers (cone bearers) on the outside but reproduced like ferns, dispersing spores into the environment.
  • They generated wood from the secondary growth of the vascular tissues.
  • During the early (Triassic) and middle (Jurassic) Mesozoic epoch, gymnosperms dominated the landscape.
  • By the middle of the Cretaceous (about 100 million years ago), angiosperms had surpassed gymnosperms as the most prevalent plant class in most terrestrial biomes.

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