Wednesday, November 21, 2007

Theme 6: REGULATION

Theme 6: REGULATION
Explanation: Everything from cells to organisms to ecosystems is in a state of dynamic balance that must be controlled by positive or negative feedback mechanisms.
Clarification: You would post here examples of how a dynamic equilibrium is maintained at different levels of life, from homesostatic control of cellular and body conditions to maintenance of population levels in ecosystems.

10 comments:

Navneet said...

Predators in an ecosystem act as a keystone species because they regulate the ecosystem. Predators are important in an ecosystem because if they are eliminated from the society then there will be a decrease in biological diversity in the ecosystem.

Muskan said...

The cell membrane aids in the job of regulation. It is selectively permeable, allowing only the nutrients and proteins that are necessary of the proper function of the cell.

Navneet said...

The human population is growing at an exponential growth and government is trying its best to control this population growth by passing programs. These programs include education and family planning which can help reduce the growth of the human population.

Muskan said...

Whenever a population is growing rapidly, there is always competition for food and other natural resources. However, the population soon reaches its carrying capacity. The carrying capacity acts as a regulating factor because the population cannot exceed past that.

Lisa said...

mammals are endothermic and have the ability to maintain a fairly constant body temperature using thermoregulation and the hypothalamus. when blood runs through the hypothalamus the receptors sense when it is cooler than normal and send signals to blood vessels near the outside layer of skin to become narrow so less heat is lost to the outside

ryan g said...

The cell wall acts as a regulator by keeping the shape of the cell and regulating water content within the plant cell.

ryan g said...

Stomates help in regulation within a plant cell by regulating the distribution of gases in and out of the cell.

ryan g said...

I don't know if this was what lisa is saying with her fancy words, but humans undergo regulation to maintain the body temperature by persperation to keep there body cool.

michelle said...

You could use the human menstrual cycle.

Changes in hormones prepare the endometrium for implantation of the embryo. Changes in LH and FSH levels, and changes in the level of estrogen and progesterone occur. The ovarian cylce has a follicular phase where the follicles grow and secrete increasing amounts of estrogen ; then ovulation occurs , and the corpus luteum secretes estrogens and progesterone( lasts 13-15 days). Menstruation occurs. Then, during the proliferative phase, estrogens from the growing follicle stimulate the endometrium to thick and become increasingly vascular. During the secretory phase, the endometrium continues to thicken, and endometrial glands grow. These changes require specific hormones that are produced during ovulation by the corpus luteum. Then, the corpus luteum disintegrates and this causes the endometrium. This cycle shows the regulation of hormones which cause certain phases of the cycle to occur.

michelle said...

Changes in hormones prepare the endometrium for implantation of the embryo. Changes in LH and FSH levels, and changes in the level of estrogen and progesterone occur. The ovarian cylce has a follicular phase where the follicles grow and secrete increasing amounts of estrogen ; then ovulation occurs , and the corpus luteum secretes estrogens and progesterone( lasts 13-15 days). Menstruation occurs. Then, during the proliferative phase, estrogens from the growing follicle stimulate the endometrium to thick and become increasingly vascular. During the secretory phase, the endometrium continues to thicken, and endometrial glands grow. These changes require specific hormones that are produced during ovulation by the corpus luteum. Then, the corpus luteum disintegrates and this causes the endometrium. This cycle shows the regulation of hormones which cause certain phases of the cycle to occur.