Mid Term Exam October 2016 5th Year Biology

Name: _______________________________ Result: ___________________________________

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Question 1- Food and Scientific Method 20m

a) Name a reagent used to test for reducing sugar. __________________________________

b) Name the elements always present in Proteins. __________________________________

c) An ‘education guess’ to explain an observation is called a ___________________________.

d) An example of a carbohydrate that has a structural role is ___________________________.

e) Name the vitamin involved in the prevention of rickets._____________________________

f) The role that an organism plays in an ecosystem is called ____________________________.

Question 2 – Metabolism and Characteristics of Life 20m

a) What is meant by the term metabolism?__________________________________________

b) Life is very difficult to define. There are characteristics which all living things share. What are

they?_______________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

c) Which characteristics are shown by the following:

i. a plant bends to grow towards a light

source__________________________________

ii. the production of seeds by a

plant______________________________________

Question 3 – Cell structure and the scientific method 20m

(a) Interpretation: 1. ___________________________ 2. _______________________

(b) Hypothesis: __________________________________________________________________

(c) Label the organelle in the image below: ________________________________

(d) State the contents of this organelle: _________________________________

(e) Name the organelle in the image above. _________________________________

(f) Outline a function of this organelle: _________________________________________________

Name the organelle in the image above.

Name: _____________________________

(g)Outline a function of this organelle: _________________________________________________

(h)

Identify the type of cell in the diagram above: _____________________________

State a reason for your answer: __________________________________________________

Label the cell: _________________________________________________________________

Question 4 – Cell structure 20m

Each of the following sentences is false. Re-write each sentence by replacing

the word in italics.

(a) The nucleus is a structure that surrounds a cell and helps control what

enters and exits the cell.

______________________________________________________________

(b) A(n) prokaryotic has membrane bound organelles.

________________________________________________________________

(c) Organelles are basic units of all organisms.

________________________________________________________________

(d)

(e) Compare and contrast eukaryotic and prokaryotic cells.

(f) Why might a microscopist, who specializes in the use of microscopes to

examine specimens, use a light microscope instead of an electron microscope?

____________________________________

(g) A material is found in an asteroid that might be a cell. What criteria must

the material meet to be considered a cell?

__________________________________________________________________________________________

__________________________________________________________________________ ________________

Question 5 20m

Fill the gaps:

(a)

(b)

(c) How does the orientation of the phospholipids in the bilayer allow a cell to interact with its

internal and external environments?

__________________________________________________________________________________

__________________________________________________________________________________

(d) Write a hypothesis for how a cell would be affected if it lost the ability to be selectively

permeable.

_________________________________________________________________________________

(e) Fill the gaps:

1. _____________________ stores sap.

2. _____________________ produces proteins.

3. _____________________generates energy for a cell.

Question 6 – Cell Structure

(a)

(b)

(c)

(d)

(e) Where is the genetic material of a cell located? _____________________-

(f)

Answer: _____________________________________

What is the function of a selectively permeable membrane?

_______________________________________________________________

(g)

(h)

(i)

(j)

(K)

(L)

__________________________________________________________________________________

__________________________________________________________________________________

Question 7 – Experiments

To test for starch

1. Name the three chemical elements present in starch.

__________________________________________________________________________________

2. To what food group does starch belong?

__________________________________________________________________________________

3. Name three foods that contain starch.

(i)

_______________________________________________________________________

(ii)

_______________________________________________________________________

(i) _____________________________________________________________________

4. What is the function of starch in the diet?

__________________________________________________________________________________

5. Draw a labeled diagram of the apparatus you will use in this experiment.

To test for reducing sugar

1. What reagent did you use?

__________________________________________________________________________________

2. Did you need to use heat and if so, how did you heat the solution?

__________________________________________________________________________________

3. When Benedict’s reagent is added to a reducing sugar and heated, what colour change occurs?

__________________________________________________________________________________

4. Suggest a control for this experiment.

__________________________________________________________________________________

5. Was there a colour change in the control?

__________________________________________________________________________________

6. If you used a mortar and pestle in this experiment what was its function?

__________________________________________________________________________________

__________________________________________________________________________________

To test for Protein

1. State one reason that your body needs protein.

__________________________________________________________________________________

2. What chemical(s) is used to test for protein?

__________________________________________________________________________________

3. When this chemical(s) is added to protein, what colour change is observed?

__________________________________________________________________________________

4. Suggest a control for this experiment?

__________________________________________________________________________________

To test for fat

1. What are the products of the digestion of fats?

__________________________________________________________________________________

2. Where is fat stored in animals?

__________________________________________________________________________________

3. What will you use to test for the presence of fat?

__________________________________________________________________________________

4. What result will indicate the presence of fat?

__________________________________________________________________________________

Examining plant cells

1. Why are stains often used when examining cells under the microscope?

__________________________________________________________________________________

__________________________________________________________________________________

2. State one precaution you should consider before carrying out this experiment:

(i) ___________________________________________________________________________

______________________________________________________________________________

3. What was the source of the plant cells used in this experiment?

__________________________________________________________________________________

4. Draw a labelled diagram of what you saw under the microscope:

Unstained Plant Cell Under Low Power Unstained Plant Cell Under High Power

Examining animal cells

1. In the space provided, draw a typical animal cell, and label the following parts:

-Cell membrane -Cytoplasm

-Nucleus -Nuclear pores

-Ribosome -Mitochondrion

-DNA

2. Describe briefly how you will obtain a sample of human cheek cells

__________________________________________________________________________________

__________________________________________________________________________________

2. Why is a mounted needle used?

__________________________________________________________________________________

3. Outline how you applied the stain to the slide

__________________________________________________________________________________

__________________________________________________________________________________

4. Why is a cover slip placed on the slide?

__________________________________________________________________________________

__________________________________________________________________________________

Questions on the effect of pH on enzyme activity:

1. What is an enzyme?

__________________________________________________________________________________

__________________________________________________________________________________

2. Name the enzyme you used and give its source

__________________________________________________________________________________

__________________________________________________________________________________

3. Name the substrate for this enzyme

___________________________________________________________________________________

4. List 3 factors that affect enzyme activity

___________________________________________________________________________________

5. Sketch a graph to show the effect of pH on enzyme activity

6. How would the graph differ for a stomach

enzyme?

___________________________________________________________________________________

___________________________________________________________________________________

7. What factors are kept constant during this experiment?

___________________________________________________________________________________

___________________________________________________________________________________

8. How each factor is is kept constant?

___________________________________________________________________________________

___________________________________________________________________________________

___________________________________________________________________________________

9. How is the rate of enzyme activity measured?

___________________________________________________________________________________

___________________________________________________________________________________

10. How did you know at which pH the enzyme worked best?

___________________________________________________________________________________

___________________________________________________________________________________

11. What is the optimum pH for the enzyme you used?

_________________________________________________________________________________

12. Enzymes are specific. What is meant by specificity of an enzyme?

_________________________________________________________________________________

_________________________________________________________________________________

13. Outline the Induced Fit Theory (Lock and Key Model)

Outline Labelled Diagram

1.__________________________________

2.__________________________________

3.__________________________________

4.__________________________________

5.__________________________________

6._________________________________