5.1.1 Coordination Flashcards
How do animals and plants respond to external and internal changes?
Animals respond Through electrical responses (via neurons), and through chemical responses (via hormones).
Plants responses are based off of a number of chemical communication systems including plant hormones. These communication systems must be coordinated to produce the required response in an organism
Why is coordination needed
As species have evolved, cells within organisms have become specialised to carry out specific functions. As a result of this, organisms need to coordinate the function of different cells and systems to operate effectively. Only few body parts can work independently. For example RBC, don’t have nucleus and can’t replicate by themselves and require a constant supply by haematopoietic stem cells. Another one: muscle cells need to constantly contract but need oxygen to do so, which they rely on from RBC
In plants, flowering needs to be coordinated with the seasons, and pollinators must coordinate with the plants. And in temperate climates, light sensitive chemicals enable plants to coordinate the development of flower buds with the lengthening days that signal the approach of spring and summer
Why do we need homeostasis
In large multicellular animals, different organs have different functions in the body. These functions must be coordinated in order to maintain a relatively constant internal environment. For example the exocrine tissue and the endocrine tissue of the pancreas work together in order to maintain a stable blood glucose concentration
What is cell signalling
A way for nervous and hormonal systems to coordinate their activities - one cell releases chemical which has an effect on another cell, known as a target cell. Through this, cells can:
Transfer signals locally between things like neurones at synapses (neurotransmitters)
Transfer signals across large distances, using hormones for example the cells or the pituitary gland secrete ADH which acts on cells in the kidney to maintain water balance in the body
How does coordination occur in plants?
Plants don’t have nervous system like animals. However to survive they still must respond to internal and external changes to their environment. E.g. plant stem grow towards a light source to maximise their rate of photosynthesis. This achieved through use of plant hormones
