Question

Failure of negative-feedback mechanisms to maintain homeostasis
A) may produce disease.
B) occurs when blood pressure increases during exercise.
C) can be corrected by stimulating positive-feedback mechanisms.
D) cannot be corrected by medical therapy.
E) all of these

Answer 1

anyone.......a medal

Answer 2

all i think :)

Answer 3

I have a medal for you. :D

Answer 4

When our negative feedback mechanisms fail, we call it "homeostatic imbalance."

Homeostatic imbalances can cause disease.
There are tons of examples.

Tay Sach's disease, for instance. It's a genetic disease.
Our lysosomes are supposed to break down lipids that build up in our brains.
But sometimes, our lysosomes don't have the right enzymes to break down these lipids.
So, these lipids build up, and cause brain and nerve damage.

------------

So we know that A is true.

The other ones aren't.

------------

B isn't true, because blood pressure increase during exercise is not a homeostatic imbalance.

Homeostatic imbalances harm us.

But blood pressure increase during exercise doesn't harm us.
It actually keeps us alive.

When we exercise, our cells need more oxygen.
And in order to get this oxygen to our organs, our hearts need to pump faster.
This causes blood pressure to increase.

---------------

C isn't true,
because Positive Feedback Mechanisms help maintain homeostasis in a completely different way.

Negative Feedback Mechanisms keep our bodies continuously healthy, over a long period of time.

Positive Feedback is more temporary, and short-term.
One example is when our blood clots, when we get cut.

Our bodies cannot make up for negative homeostatic imbalance with positive feedback.

-----------------

D isn't true.

Cancer is a result of a homeostatic imbalance.
It happens when our cells can't divide at a steady pace anymore.

And obviously, cancer can be corrected with medical therapy.

---------------

And given all that, the answer isn't E.