Answer:
Harmful to the existing habitat and inhabitants
Foreign
Fast reproduction rate
Pollen tube growth is one of the most fascinating—and essential—phenomena in the life cycle of flowering plants. After a compatible interaction between pollen grains and the stigma surface, the pollen germinates and forms the pollen tube, which grows through the stigma, style, and transmitting tract to deliver the sperm cells to the ovule."
2) Although pollens of many species germinate in simple aqueous media, stigmas do not provide satisfactory sites for the germination of most foreign pollen... Stigmas not only provide the proper conditions for the germination of pollen from their particular species, they actively inhibit the germination of pollen of many unrelated species.
Answer:
Yeast cell structure
Each yeast cell has a distinct cell wall enclosing granular cytoplasm, within which can be seen a large vacoule and a nucleus (Fig. 214). The vacuole varies much in size according to the state of activity of the cell.
Yeast contains almost the same organelles of a mature eukaryotic cell. Nucleus, Golgi apparatus, mitochondria, endoplasmic reticulum, vacuole, and cytoskeleton are the most important one. Yeast cell particle size is typically of 5×10μm.
Explanation:
Yet, we don't always think of yeast as something remarkable. Instead, it's often perceived as plain or dull—a single-celled organism that, like a plant, lacks the ability to move on its own accord.