9700 · 14.2
Homeostasis in plants
Just like animals, plants need to keep their internal conditions stable to survive and thrive. This is called homeostasis, and for plants, it mainly involves carefully managing their water levels, temperature, and carbon dioxide intake. Without this delicate balance, plants couldn't photosynthesise, grow, or even stand upright.
Need to know
What you need to know
- wall adjacent to the pore is very thick.
- wall furthest from the pore is thin 2) bundles of cellulose microfibrils are arranged as hoops around cells so that as the cell becomes turgid, the cell mostly increases in length and not diameter 3) thin outer wall bends more readily than the thick inner one, causing the guard cell to become curved.
- the removal of hydrogen ions has left the inside of the cell negatively charged compared to the outside.
- as K + ions have a positive charge, they are drawn down an electrical gradient towards the negatively charged region.
- they also diffuse into the cells down a concentration gradient.
- abscisic acid (ABA) is a stress hormone that is secreted in response to difficult environmental conditions such as very high temperatures or reduced water supply.
- for people with diabetes, the uptake of glucose into cells is slow even when the blood glucose concentration is very high.
- because cells lack glucose, they metabolise fats and proteins as alternate energy sources.
Explanation
Plants' Internal Balance
- Grasp why stable water potential is non-negotiable for plants.
- Understand how stomata are the plant's 'gatekeepers' for water and CO2.
- Learn the roles of different plant structures and hormones in regulation.
- Practise explaining these mechanisms in detail for exam success.