The walls of xylem cells are lignified (strengthened with a substance called lignin ). This allows the xylem to withstand pressure changes as water moves through the plant.
The cell membrane is flexible because of the presence of oil like substances called phospholipids, which gives it a fluid nature. While as the cell walls are rigid because of the presence of the thick layers of the substances like cellulose in plants, chitin in fungi and peptidoglycon in bacteria.
Answer:
<h2>Coevolution</h2>
Explanation:
Coevolution : It is the influence of closely associated species on each other in their evolution, they affect each other.
In coevolution , two or more species reciprocally affect evolution of each other by natural selection.
Coevolution Examples:
There are lots of examples of coevolution, some are here
i) coevolution of Predator-Prey , this relationship is one of the most common examples of coevolution.
ii) coevolution of Herbivores and plants,
iii) coevolution of Acacia ants and Acacias and
iii) coevolution of Flowering Plants and Pollinators and many others.
False, that is a close answer and can be easily confused with the right answer which is "Centromere" it is the specialized region of the chromosome where two sister chromatids are most closely attached.
The centrosome is like the organization center in the process of cell division. Has two centrioles.
<span>A shelled, water-retaining egg with four membranes that enables reptiles, birds, and egg-laying mammals to complete their life cycles on dry land</span>
Answer:
lacks a well defined nucleus
lacks cell organelles.
