Lecture Exam 1 Open-Ended Questions

Sara is giving birth to her first child. She is concerned that her labor is taking longer than she thought it would. Why does giving birth usually take time for the contractions to proceed to the point when the child is born?

Childbirth is based on the increasing levels of oxytocin that cause the uterine contractions. Under positive feedback, oxytocin levels increase which results in increasing strong contractions by the upper uterus that will ultimately result in the birth of the child. But this positive feedback needs numerous contraction cycles to overcome the muscular resistance to stretching in the lower uterus in order for the head to pass

You are home watching the season finale of The Walking Dead (TWD), alone and in the dark. As you are watching it, a really intense scene involving a fight scene (between Negan and Rick of course) and a room full of walkers has your complete attention. As you are watching the scene you notice your blood pressure is increasing and you start sweating from the excitement and action. During the next commercial you also observe the sweating stops and the BP returns to normal. Using the steps involved in a Negative Feedback System identify each step of the system and describe/explain what is occurring during each step of the feedback loop.

Negative feedback system has 3 basic components. - a Receptor - a Control Center - an Effector. The RECEPTOR monitors changes in a controlled condition and sends input to a control center. The CONTROL CENTER is the component in a feedback system that compares the value to the normal range. If the value deviates too much from the set point, then the control center activates an effector. The EFFECTOR receives output from the control center and produces a response or effect that changes the controlled condition.

Compare and contrast negative feedback mechanisms and positive feedback mechanisms. Within your answer include which mechanism directly supports homeostasis and which one works against homeostasis. Also explain why a mechanism that works against homeostasis is still beneficial to the body. Provide a specific example of each type of feedback and explain how the example is that type of feedback.

Positive feedback mechanisms occurs when the product of a reaction leads to an increase in that reaction. It moves a system further away from the target of equilibrium and it does this by amplifying the effects of a product or event and occurs when something needs to happen quickly. This feedback mechanism works against homeostasis. An example of a positive feedback mechanism is childbirth. This is an example of a positive feedback mechanism because when a baby's head puts pressure on the cervix, this stimulates the receptor cells to send a chemical signal to the brain, which allows for the release of oxytocin. Negative feedback mechanisms occur when the the product of a reaction leads to a decrease in that reaction. They are responsible for the stabilization of a system, and it directly supports homeostasis. An example of a negative feedback mechanism is the regulation of temperature. When the body rises above the normal internal temperature, it starts to sweat and cool the body down. Through this, normal body temperature regained.

Explain the major difference(s) between polar and nonpolar covalent bonds?

The difference between polar and non-polar bonds is that a polar bond means the electrons are not equally shared, while the non-polar bonds are equally shared.

Discuss how Dehydration Synthesis builds macromolecules from monomers. Within your explanation include each type of Biomolecule discussed in class, its monomer, the type of bond that is formed, and which functional groups are involved during the formation of the macromolecule.

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