Biology 12

Chapter 4 Homeostatic Mechanisms • MHR 135

COMMUNICATING

29.Describe and illustrate two negative feedback
loops that have opposite physiological effects.

30.Describe and illustrate a negative feedback loop
in which bicarbonate ions help regulate the pH
of blood.

31.Create a flowchart that illustrates the relationship
between different immune system cells.

32.Create a flowchart that illustrates how the

filtrate is modified by the processes of active

and passive transport as it flows through a

single nephron in the human kidney.

33.Create a flowchart that lists the steps that can

lead to heat stroke in an athlete.

MAKING CONNECTIONS

34.Meal A consists of mostly simple carbohydrates
with some proteins. Meal B consists of mostly
complex carbohydrates with some proteins.
(a)Compare the glucose levels you would
expect to find soon after eating each meal.
(b)Describe how each meal could affect the
feedback loops created by the antagonistic
hormones insulin and glucagon.

35.Someone with Type 2 diabetes is concerned
about kidney failure. This person then decides
to switch to a high protein, low carbohydrate
diet. Is this a wise decision? Explain the
impact of this diet on the kidney.

36. (a)Use a feedback model to show how diet
    and exercise can moderate the effect of
    Type 2 diabetes.
    (b)Explain why this model is less effective
    for Type 1 diabetes.

37.Explain how you might develop different types

of allergies than the other members of your

family do.

38.Explain why babies and young children might

contract infectious diseases more frequently

than adolescents do.

39.Explain how hypoglycemia (low blood sugar)

episodes can turn into life-threatening

situations for people with Type 1 diabetes.

40.How do cells that provide cellular immunity

sometimes trigger allergic reactions when they

come into contact with environmental

allergens?

41.What are some daily habits you could adopt

to help reduce your chances of contracting a

contagious disease (such as a cold or flu) from

people you come into contact with on a regular

basis?

26.A particular chemotherapy prevents the
formation of microtubules that form spindle
fibres for mitosis. Predict which immune cells

will be adversely affected by this therapy.

How can you determine if your prediction

is correct?

27.Design a test that could be used to confirm a

diagnosis of diabetes in a patient who displays

some of the common symptoms of the disease.

28.How could transplanting healthy islet cells into

people with Type 1 diabetes help them manage

their blood sugar levels more effectively?

Develop a hypothetical clinical trial that would

test the effectiveness of a new transplant

procedure. Focus on creating appropriate

qualifying criteria for prospective participants,

and on establishing criteria for evaluating the

procedure’s effectiveness.

0

200

6 A.M.

100

300

400

500

12

noon

6 P.M. 12

midnight

Unstable uncontrolled diabetes

breakfast

246

476

354

161

423

59

267

491

297

lunch supper

Blood glucose (mg/100 mL)