Answer:
controlled the fertilization process.
Explanation:
Mendel took precautions to avoid contamination by pollen through self pollination of the P generation. He controlled the fertilization processes between the plants. He self pollinated the first pureline varieties to form the P generation. He then cross pollinated them to get F1 generation. Every step of his experiment was controlled.
Two factors contributed to the success of the pteridophytes: the extreme miniaturization of the gametophytic generation and an important development of the sporophytic generation (development of the tree forms).
Pteridophytes are a group of plants that peaked in the Carboniferous (-300 million years). It is the first great terrestrial plant civilization. These plants would have appeared in the Devonian -400 million years ago, perhaps from certain primitive terrestrial plants which, unlike bryophytes, would have favored the diploid generation on the haploid generation.
Particularly well adapted to terrestrial life, they have created, thanks to the development of tree forms, immense forests whose fossilization is at the origin of coal deposits.
Pteridophytes are at the origin of an evolutionary lineage based on the extreme miniaturization of gametophytic generation and an important development of sporophytic generation, leading to all tracheophytes including current flowering plants. Pteridophytes are well adapted to terrestrial life, however fertilization still requires the presence of water since male gametes are swimmers.
<span>The deposition of heavy sediment can significantly diminish the water quality and aquatic habitat. The sentiment in the water can reduce the sunlight that reaches the floor of the waterway, affecting animal and plant life. For example, photosynthesis may be less effective due to the decreased sunlight and the gills of fish may get clogged from the sediment.</span>
