The function of root hair cells is to increase the ability to take in water and mineral salts so as to provide the plant with the nutrients that it needs. It has adaptations to ensure that it can fulfill its role to the best of its ability. Root hair cells have tiny hairs which are long and this creates a larger surface area that in turn leads to a greater absorption rate for water for example. A larger surface area also speeds up the rate of diffusion for the root hair cells, hence a more effective transportation goes on in the plant. The process of Active Transport also happens within the cells and this process involves water and minerals traveling from a lower concentration to a higher concentration. The minerals that travel from a lower concentration stem from the soil which the roots of the plant are in and the minerals of a higher concentration is from the plant itself. This is because the plant needs to get the maximum nutrients it can to carry out photosynthesis well. If all these processes happen, homeostasis will then be able to take place since we can observe water regulation by the root hair cells of a plant, meaning that it is their role to maintain a constant internal environment for the plant cells.
The function of the villi is also to increase the surface area for absorption in our small intestines, thus the small intestine is covered by millions of villi which have 4 layers and extend about 1 mm into the lumen. Once the molecules of amino acids, glucose etc. cross the epithelium that the small intestinal villi covers, these molecules diffuse into a capillary network and into our bloodstream. However, some molecules (mostly fats), are not transported into the small capillaries but into the lymphatic vessel.
Therefore, we can see that the similarities of root hair cells and the villi is that:
- Both absorb food in the simplest form (minerals and salt), albeit from different sources
- Both have adaptations to ensure a greater surface area for absorption of water and nutrients.
- Both ensure successful homeostasis through Active Transport and diffusion respectively.