BIOL0601 Module 1 Assignment 1 (M1A1)

BIOL0601Provincial Biology: Module 5: Human Physiology and Anatomy 2

BIOL0601 Module 5 Assignment 5 (M5A)

Introduction

BIOL0601 Provincial Biology

Assignment 5

Instructions:

Type your name in the header On Page 2. (First select Header and Footer in Words View menu or double click in the header area..)

For each answer, at least one dark blue blank line has been provided. Double-click on the line and start typing your answer. It will automatically appear in a distinctive style.

When several blank lines are provided for an answer, clean up by deleting the extra lines after you have typed your answer.

For the long answer questions, insert your answer below each question.

Sometime you will be asked to perform a lab exercise before you have finished your text work.

Only submit your work to your tutor when all the work in the assignment has been completed. If sending your file to your tutor as an email attachment, ensure that it has a file name that includes the course number, assignment number and your name.

e.g. BIOL0601_A2_Chiu.doc (with your name in place of Chiu.)

Topic

Marks

Diagrams

8

Terms and Definitions

12

Short Answer Questions

35

Long Answer Questions

25

Lab 5A

10

Lab 5B

10

Total marks

/100

/100

Diagrams

1. Place the name of the described structure in the space beside the description. Label the diagram below using the letter associated with each structure. (8 marks)

description

name

A

this structure stores the fluid which serves as an emulsifying agent in the digestion of fat.

B

this organ secretes the two hormones involved in the control of blood glucose levels.

C

produces the enzyme amylase which begins the digestion of starch.

D

the largest organ in the body, it processes nutrients and detoxifies the blood.

E

this structure is a temporary storage area for solid waste.

F

this is a vestigial structure.

G

most of the digestion of food and the absorption of nutrients takes place here.

H

this structure is responsible for reclaiming water for the body.

2.

With reference to the diagram above, fill in the chart with the name of the structure and its function. (4 marks)

name of structure

function

A

B

C

D

Terms (12 marks)

Short Answer Questions

1. The pancreas is both an endocrine and an exocrine gland. Discuss using specific examples to illustrate your answer. (4 marks)

2. When the lights are turned off, it takes a while before you are able see, and about twenty minutes until night vision is fully functional, and for sharpest night vision, one looks sideways. How do the properties of the cornea and rods and the cones relate to this? (5 marks)

3. Compare and contrast the sympathetic and parasympathetic nervous systems. (5 marks)

4. Describe the difference between the composition of the blood and the urine, and how the kidney accomplishes this. (6 marks)

5. Describe the components of a reflex arc (spinal reflex). What is the importance of a reflex arc to an organism?

(4 marks)

6. Describe how a nerve impulse is transmitted along a nerve fibre and explain how myelin is involved in the process. (6 marks)

Long Answer Questions

Answer the following questions on a separate piece of paper. Each of your answers should be two to three paragraphs long. Use your own wording.

1. Explain how insulin and glucagon maintain blood glucose levels. (4 marks)

2. This diagram illustrates the mechanism that controls the level of thyroxin in the body. Boxes on the left hand side identify a hormone. Boxes on the right identify the feedback mechanism and target organ. Fill in the boxes so as to describe the homeostatic mechanism that controls the level of thyroxine in circulation. (10 marks)

3. Imagine that you are eating a roast beef sandwich (it contains protein, carbohydrate and lipids). Follow the food through the digestive system, and describe what is happening to it as it passes through each of the sections. Be sure to include both chemical and mechanical events, and the accessory organs that are involved. (12 marks)

BONUS QUESTION (5 marks)

Digestion of the food takes place outside the body. Do you agree or disagree with this statement? Justify your choice.

Lab 5A: The Digestion of Starch

Introduction

The digestive tract is essentially a tube that runs through the body. In order for the nutrients in the food to be available for use in the body, the large molecules in our food need to be broken down. The smaller nutrient molecules can then pass through the walls of the digestive system and enter the blood stream.

The digestion of starch starts in the mouth by the action of an enzyme, salivary amylase. You will investigate this process and demonstrate the breakdown of starch by salivary amylase and the movement of the smaller molecule, glucose, through a selectively permeable membrane. In preparation for this lab review the starch test, and the structure of starch and of glucose from Module 1.

Materials

distilled water or water that has been sitting overnight

unsalted soda cracker

starch solution

tincture of iodine

glucose test strips

Apparatus

several small drinking glasses

4 baby food jars

dialysis tubing

string

Method

1. Collect all the materials required for the lab and prepare your laboratory space. Read the method over ahead of time so that you have a general overview of what you will be doing.

2. Place an unsalted soda cracker in your mouth and chew it up until it forms a moist paste in your mouth. Hold this in your mouth until you begin to notice a taste difference. Describe this taste difference in the Results section.

3. The source of salivary amylase for the experiment is your saliva. Label a drinking glass salivary amylase. Rinse your mouth out well. Take a mouth full of water and swish it around your mouth. Hold it in your mouth for several minutes (think thoughts that will make your mouth water!) When the time is up, spit the water in a clean drinking glass. Repeat this until you have collected about 100 mL of saliva solution. Keep this solution warm by placing the jar in a water bath (you can use the sink for this) in which the water is about 37 C (body temperature).

4. Remove two small samples (about 5 mL) of the solution and place them in jars. Test one of the samples with tincture of iodine and the other with a glucose strip. Record your results in the Table 5.1.1

note: only record observations

5. Place about 50 mL of water in a glass jar labelled reaction container and place the jar in the warm water bath. Test two 5 mL samples of the water with tincture of iodine and a glucose test strip. Record your results in Chart 5.1.1.

6. Cut a strip of dialysis tubing about 20 cm long. Thoroughly wet the tubing with water. Crimp one end of the tubing and tie it off with string. This must be done so as to produce a water tight seal.

7. The dialysis strip is in fact a tube of dialysis membrane. It can be opened up to form a tube (now closed at one end). Using a wet toothpick, or the blunt end of a needle, probe for an opening at the top corner of the tube. Once you have created a small opening, carefully enlarge it so that it can hold about 10 mL

8. Place about 10 mL of starch solution in the warm salivary amylase solution. Mix thoroughly. Transfer some of this solution into the cavity in the dialysis tubing. Use this liquid to help open the rest of the tube. Add more salivary amylase/starch solution until you have about 50 mL inside the dialysis tube. Close off the open end of the dialysis tubing creating a water tight seal. Quickly rinse the outside of the dialysis tube.

9. Place the dialysis tube containing the salivary amylase/starch solution in the warm water in the reaction container. Keep this jar in the warm water bath for about 20 minutes.

10. After 20 minutes, remove the dialysis tube from the reaction container. Open the tubing and place half the contents in each of two clean jars. Test one jar with tincture of iodine, and one with the glucose test strip. Record your results in Chart 5.1.2.

11. Divide the water from the reaction container between 2 clean jars. Test one half with tincture of iodine, and one with a glucose test strip. Record your results in Chart 5.1.2

12. Clean up your laboratory space and replace all equipment

Results

Chewed soda cracker

Chart 5.1.1

testing salivary amylase solution

iodine

glucose test strip

testing water before

iodine

glucose test strip

After 20 minutes

testing dialysis tubing contents

iodine

glucose test strip

testing the water after 20 minutes

iodine

glucose test strip

Thinking About the Results

1. After a while you should begin to taste sweetness in your mouth. What can account for the developing sweet taste and what chemicals are involved in this? (remember enzyme action: enzyme, substrate, product)

2. Explain what happened in this experiment.

3. Glucose is a monomer and starch is a polymer. Use this idea to explain the experimental results. (remember that dialysis tubing is a selectively permeable membrane; also remember the process of hydrolysis)

Congratulations, you have now completed Lab 5A

Lab 5B: The Senses

Answer the questions in the spaces provided.

Introduction

The senses evolved to allow a organism to collect the information about its environment required for survival and reproduction. In this activity we are going to look at a few of lesser known consequences of the design of our sensory system.

1. Locating the blind spot

Examine Figure 14.6 in your text.

In this exercise, you will find the entry point of the optic nerve into the interior of the eye. At this entry point there are no sensory receptors (rods and cones), and therefore, it is a blind spot within your field of view.

1. Hold the page at arms length. (Some students may need to start from a point a bit past arms length).

1. Close your left eye.

1. Stare at the cross with your right eye.

1. Continue staring at the cross as you slowly move the paper towards directly your head. Do not move the paper sideways in order to see the dot! Measure the distance of the paper from your eye when the dot disappeared.

1. Repeat the procedure with the right eye closed and stare at the dot with your left eye.

1. Describe what happened.

As the book is drawn toward the face the dot will disappear. This happens when the image of the dot falls on the position where the optic nerve passes through the retina.

1. At what distance was your blind spot?

Results will vary

1. Normally, we are not bothered by the blind spot. How does the eye compensate for the presence of a blind spot in each eye?

The blind spots of the two eyes do not correspond in our visual field. The right eye makes up for the blind spot of the left eye, and the left eye makes up for the blind spot of the right eye.

1. The Sense of Touch Two Point Discrimination

You can remember seeing a car coming towards you at night. In the distance, the headlights appear as a single light. As the car approached, at a certain distance, the two headlights becomes individually visible. The distance at which the single light can be seen as two relies on the resolving power of your eyes.

The situation is similar for your skin. If two points are placed close together, on some locations the points will feel like a single point, and in other places, your sense of touch will be able to resolve the stimulus into two distinct points.

Sharpen 3 pencils (or use 3 skewers) Attach two of them together them together with tape so that the points are even with each other. Using the areas of skin mentioned in Table 5.2.1, touch the person with the single pencil, then with the double pencil and ask them what they felt. Record these results as trial 1 and trial 2. Continue with the other areas of skin alternating using the single pencil first or the double pencil first. Ask the person to indicate whether she or he feels one point or two points. Record the responses in Table 5.2.1

Table 5.2.1: Number of points felt in different body areas (felt as 1 or 2 points)

Spot tested

Number of points felt

trial 1

trial 2

Wrist

Thumb tip

Cheek

Lip

Middle of back

Thigh

How does the number of touch receptors in a given location of the body relate to that locations function?

1. The Goldilocks Effect (not too hot, not too cold just right!)

We can all remember stepping into a hot shower. Initially it feels like the water is scalding, but, given a bit of time, it begins to feel just right. This happens because of the way our skin senses temperature. The environmental temperature is judged by comparison to the skin temperature.

Collect 3 containers into which you can easily insert your hand. Fill one with ice water, one with lukewarm water (about 40 C) and the other with very hot water.

Place your right hand in lukewarm water. Place your left hand in the hot water and keep it there for about 1 minute. Remove it from the hot water and place it in the lukewarm water. Describe the sensation.

Wait a few minutes for your hand to recover (or use the other hand), then repeat the process, only this time place your hand in the ice water first, then in the lukewarm water. Describe the sensation

Why temperature of the lukewarm water does not change significantly, yet it felt both hot and cold. How could this be?

Relate the results to everyday life (hint: think of taking a shower or hot bath)

Congratulations, you have now completed Lab 5B.

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