A cell wall is a structural layer that surrounds some types of cells, situated outside the cell membrane. It can be tough, flexible, and sometimes rigid. It provides cells with both structural support and protection, and also acts as a filtering mechanism. Cell walls are present in plants, fungi and prokaryotic cells, where a major function is to act as pressure vessels, preventing over-expansion when water enters the cells. Cell walls are absent from mycoplasmas.
Biotic because abioctic is <span>physical rather than biological; not derived from living organisms.</span>
I think it’s C but not precisely sure about it
Clues such as fossils such as bones, footprints, tar, etc, preserved underground helped inform scientists. You can also count how old a tree is when you cut it open and there are some alive for thousands of years so that is a possible way.
Answer:
Explanation:
1)Pfr/Pr
2) Pr
3)far-red
Explanation:
The leaves at the top of a tree’s canopy are exposed to direct sunlight during the day, and their phytochromes will occur in a high *Pfr/Pr* ratio. Meanwhile, the leaves of the same tree at the bottom of the canopy are highly shaded during the day and will likely have a higher proportion of the * ( PHYTOCHROME )Pr *;form of phytochrome present due to exposure to a higher proportion of *FAR RED * light.
Plants make use of the phytochrome system to it's adjust growth based on the seasons. Through phytochrome plants is able to respond to the timing and duration of dark and light periods. At dawn, all the phytochrome molecules present in the leaved are converted to the active Pfr form until sunset this is because the sun is unfiltered, and unfiltered sunlight has high percentage of red light, but lower far-red light, with the help of phytochrome system , the plants is able to compare the length of dark periods over several days.
