Lesson 2: Homeostatic Mechanisms
1. How is the concept of common ancestry supposed by continuity in homeostatic mechanisms? How do changes in the environmental conditions affect this continuity?
By these homeostatic mechanisms being present in several different species for generations, it shows that, at one point, there was one organism that had the characteristic/trait and that it was essential for survival. Instead of all these different species just randomly obtaining the same mechanisms, it makes more sense that it was passed on from one common ancestor. Sometimes changes in the environment can prevent these mechanisms from appearing because they simply are just not necessary.
2. Explain how one of the following mechanisms is used for obtaining nutrients and eliminating wastes.
Gastrovascular cavities, like those in the pond-dwelling amoeba, open directly to the external environment, allowing direct exchange between the cells and the environment. Because it opens up, the inner and outer layers of the cells are exposed to the pond water where it obtains its nutrients.
3. Explain how homeostatic control systems in species of microbes, plants, and animals support common ancestry.
Thermoregulation is one example of homeostatic control; it allows species to maintain an internal temperature within a specific range. If a species’ temperature increased or decreased dramatically, it would severely affect certain enzyme/protein activities. Homeostatic control systems, such as thermoregulation, reflect common ancestry because it shows that all species, at one point, shared an ancestor that started the idea of thermoregulation. It became evident that it was necessary for survival, therefore it was passed on from generation to generation.
4. How do disruptions at the molecular and cellular levels affect the health of the organism?
Dehydration affects the health of the organism at the molecular and cellular level. Water is essential for cell function; without water, cells cannot perform their normal flow of nutrients and hormones. Cells are constantly surrounded by water and if an organism is dehydrated (loss of body water) then the cells are no longer surrounded by water, becoming less permeable.
By these homeostatic mechanisms being present in several different species for generations, it shows that, at one point, there was one organism that had the characteristic/trait and that it was essential for survival. Instead of all these different species just randomly obtaining the same mechanisms, it makes more sense that it was passed on from one common ancestor. Sometimes changes in the environment can prevent these mechanisms from appearing because they simply are just not necessary.
2. Explain how one of the following mechanisms is used for obtaining nutrients and eliminating wastes.
Gastrovascular cavities, like those in the pond-dwelling amoeba, open directly to the external environment, allowing direct exchange between the cells and the environment. Because it opens up, the inner and outer layers of the cells are exposed to the pond water where it obtains its nutrients.
3. Explain how homeostatic control systems in species of microbes, plants, and animals support common ancestry.
Thermoregulation is one example of homeostatic control; it allows species to maintain an internal temperature within a specific range. If a species’ temperature increased or decreased dramatically, it would severely affect certain enzyme/protein activities. Homeostatic control systems, such as thermoregulation, reflect common ancestry because it shows that all species, at one point, shared an ancestor that started the idea of thermoregulation. It became evident that it was necessary for survival, therefore it was passed on from generation to generation.
4. How do disruptions at the molecular and cellular levels affect the health of the organism?
Dehydration affects the health of the organism at the molecular and cellular level. Water is essential for cell function; without water, cells cannot perform their normal flow of nutrients and hormones. Cells are constantly surrounded by water and if an organism is dehydrated (loss of body water) then the cells are no longer surrounded by water, becoming less permeable.