Biology PK2 L6 2010

7/31/2019 Biology PK2 L6 2010

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Name : ………………………………… Class : Lower 6 Science

SEKOLAH MENENGAH KEBANGSAAN BANDAR UTAMA

NO. 1, PINTASAN BANDAR UTAMA

47800 PETALING JAYA

PENILAIAN KURIKULUM II 2010 964BIOLOGY

TINGKATAN 6 BAWAH SAINS

Ogos

1½ jam Satu jam tiga puluh minit

SECTION A (20 marks) : Answer all the questions

Write your answers for objective questions in the space provided below.

1 6 11 16 21 26

2 7 12 17 22 27

3 8 13 18 23 28

4 9 14 19 24 29

5 10 15 20 25 30

1. If 60% of the bases in one strand of DNA are adenine and guanine, the percentage of thymine and cytosine in the complementary strand is

A. 20% C. 40%

B. 30% D. 60%

2. Which molecular group and characteristic correspond?

Group CharacteristicA. Methyl Polar, involved in the hydrophilic reactions

B. Carboxyl Basic, involved in the formation of peptide bonds

C. Amino Acidic, involved in the formation of peptide bondsD. Hydroxyl Polar, involved in condensation and hydrolytic reactions

3. Which is not true of a mito hondrion?

A. It is the site of Krebs cycle.B. It contains DNA.

C. It possesses two layers of membranes.

D. The folded inner membrane is called thylakoid.

4. Which statement about triglycerides is correct?

A. They are made up of three fatty acids combined with glycogenB. They are more saturated with hydrogen compared with phospholipids.

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C. They form a bilayer in the membranes of cells.

D. They have a lower ratio of oxygen to carbon compared with carbohydrates.

5. What is the chemical nature of collagen?

A. Phospholipids C. polypeptide

B. Polynucleotide D. polysaccharide

6. What is the process involved in making a peptide bond?A. condensation involving the formation of a water moleculeB. condensation involving the splitting of a water molecule

C. hydrolysis involving the formation of a water molecule

D. hydrolysis involving the splitting of a water molecule

7. Fatty acids, proteins and cholesterol are all found within the lipid bilayer of cell surface

membranes.

Why are they found within the lipid bilayer?

A. They are hydrophilic. C. They are large, insoluble molecules.

B. They are hydrophobic. D. They can form a fluid mosaic.

8. Which statement is the best explanation of why sucrose rather than glucose is

transported by phloem?

A. Sucrose can pass through plant cell surface membranes more easily.B. Sucrose is a disaccharide and is more easily converted to starch.

C. Sucrose is a non-reducing sugar, so is less reactive.

D. Sucrose synthesis requires less energy.

9. Pregnant women are advised to increase their intake of vitamin D.

What would be the risk as a result of not following this advice?

A. The baby might be born blind.B. The baby might be more susceptible to infections.

C. The mother might suffer from dry, rough skin.D. The mother might suffer from weak bones.

10. How many different essential amino acids should be included in a adult human’s diet?

A. 4 C. 12B. 8 D. 20

11. What is the function of goblet cells in the trachea?A. to carry cilia C. to increase elasticity

B. to engulf bacteria D. to produce mucus

12. What is the order of size of cell components

Largest smallest

A.

B.C.

D.

mitochondria

nucleiRibosomes

Starch grains

ribosomes

chloroplastsmitochondria

mitochondria

starch grains

mitochondriachloroplasts

chloroplasts

nuclei

ribosomesstarch grains

ribosomes

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13. The diagram shows the structure of a typical plant cell.

Which cell component is also present in prokaryotes?

14. What is responsible for the high resolution of the electron microscope?A. high magnification C. use of heavy metal stains

B. short wavelength of the electron beam D. very thin sections

15. A piece of mammalian tissue was homogenized and subjected to differential

centrifugation to yield four subcellular fractions. The activity within each fraction of

four different types of enzyme, A, B, C and D, was investigated.

Which bar chart shows the results of investigating hydrolytic enzyme activity?

16. What are the features of triglycerides?

Polar Less dense than

water

Higher energy value

than carbohydrates

Lower proportion of

hydrogen than incarbohydrates

A.B.

C.

D.

√

√

x

x

√

x

√

x

x

√

√

x

x

√

x

√

17. Which polysaccharides are branched and which are unbranched?

Branched Unbranched

A.

B.

C.D.

amyloses

amylopectin

celluloseglycogen

glycogen

cellulose

amylaseamylopectin

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18. The diagram shows a molecule.

Which arrow labels a peptide bond?

19. Which bonds are the last to break when an enzyme is heated?

A. disulphide C. hydrophobic interactionsB. hydrogen D. ionic

20. Which substance contains carbon, hydrogen oxygen and nitrogen?A. collagen C. amylopectin

B. glycogen D. triglyceride

21. Which process is the movement of molecules that are too large to diffuse in through a

cell surface membrane?

A. active transport C. facilitated diffusion

B. endocytosis D. osmosis

22. A plant cell is placed in a solution with a less negative (higher) wter potential than the

cell contents.

Which change occurs in the cell and what causes the change?

change cause

A.

B.

C.

D.

cell becomes more flaccid

cell becomes more flaccid

cell becomes more turgid

cell becomes more turgid

solution diffuses out of the cell

water diffuses out of the cell

solution diffuses into cell

water diffuses into cell

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23. The diagram shows part of a DNA molecule

Which letters indicate cytosine, deoxyribose, phosphate and thymine?

cytosine deoxyribose phosphate thymine

A.B.

C.

D

WY

Z

Y

XX

W

Z

YW

X

X

ZZ

Y

W

24. Why is the mass flow of sap through sieve elements described as an active process?

A. Phloem sap is able to flow in sieve elements against the pull of gravity.B. Sucrose is loaded into a sieve element against a concentration gradient

C. Sucrose passes out of the phloem into regions where cells are dividing.

D. Water follow sucrose into a sieve element down a water potential gradient.

25. The diagram below shows two adjacent plant cells.

Ψ8 = -2 300 kPa

Ψ p = 1 100 kPa

Cell A

Ψ8 = -1 700 kPa

Ψ p = 900 kPa

Cell B

What is the water potential (Ψcell) of cells A and B at equilibrium?

A. -1 200 kPa C. -1 000 kPa

B. -800 kPa D. -3 000 kPa

26. In an active sodium-potassium pump, how many sodium and potassium ions are

transported across the membrane in one complete turn?

Sodium Potassium

A.B.

C.

D.

12

2

3

11

3

2

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27. The following diagram shows the structure of a nucleotide.

Which of the following is true about the above nucleotide structure?I. Has purine base

II. Is a deoxyribonucleotide molecule

III. Is a substrate for ribonucleic acid synthesisIV. Has a phosphodiester bond

V. Is used as an energy source

B. I, II and V C. II, III and IVC. I, III and IV D. III, IV and V

28. Which of the following structures of membrane bound organelles is correctly matchedwith its function?

Structure Function

A.

B.

C.D.

An extensive network of tubes; each tube is bound by asingle membrane.

A stack of elongated, curved sacs; each sac is bound by a

single membrane.

A spherical sac bound by a single membrane.A sac bound by two membranes, the inner is highly folded

Lipid synthesis

Photosynthesis

Protein synthesisPackaging of

proteins

29. Which of the following diagrams represents a prokaryote?

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A. I only C. III and IV

B. I and II D. IV only

30. The table below shows the components of a cell membrane and their functions.

Components of a cell membrane Functions

I.

II.

III.

IV

Oligosaccharide

Lecithin

Protein

Cholesterol

(p) Acts as a receptor to a certain moleculesuch as a hormone.

(q) As an indicator so that the cells can

recognize each other (r) Gives the semipermeable and selective

characteristics to the membrane.

(s) Maintains the fluid characteristics of themembrane

Which of the following is correct for the components of a cell membrane and their functions

I II III IVA. (p) (q) (r) (s)

B. (q) (r) (p) (s)

C. (r) (p) (s) (q)

D. (s) (r) (q) (p)

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: Answer the questions

1. Figure 1 shows drawings from electron micrographs of cells from the lining of the

human gut.

Figure 1

Cell A secretes large amounts of the protein pepsinogen into the stomach.

Cell B is from the lining of the small intestine. This type of cell is responsible for theuptake both by diffusion and active transport of the soluble products of digestion such

as hexose sugars and amino acids.

(a) Complete the table below by listing three ways in which the structure of cell Adiffers from that of cell B [3]

Cell A Cell B

1

2

3

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(b) Explain the significance of the labeled structures for the particular function of

(i) cell A : P and Q

……………………………………………………………………………………

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…………………………………………………………………………………………………………………………………………………………………………

………[2]

(ii) cell B : R and S.

……………………………………………………………………………………

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….

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…[2]

(c) Outline how a protein, such as pepsinogen, may be passed out of cell A

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……..……………………………………………………………………………….

….

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…[2]

(d) Distinguish between resolution and magnification.

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……………………………………………………………………………………

…[1]

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2. Figure 2 shows part of the molecular structure of cellulose and starch (amylase). Both

cellulose and starch are synthesized in plants from glucose.

Figure 2

(a) Give three differences in molecular structure between cellulose and starch.

…..……………………………………………………………………………….….

……………………………………………………………………………………

……………………………………………………………………………………

……

…..……………………………………………………………………………….….

……………………………………………………………………………………

……………………………………………………………………………………

…[3]

Cellulose has a structural function in plants while starch has a storage function.

(b) Relate these functional differences to the differences in molecular structure of cellulose and starch

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……

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……………………………………………………………………………………

…[4]

(c) Name the bond formed between adjacent glucose molecules in starch and cellulose.

……………………………………………………………………………………

[1]

(d) Suggest why amylase, the enzyme that catalyses the hydrolysis of starch, will not

catalyses the hydrolysis of cellulose.

.

……………………………………………………………………………………

……………………………………………………………………………………

[2]

3. The diagram represents a phospholipids molecule.

(a) (i) Name the parts of the molecule labeled A, B and C

A:.

…………………………………………………………………………………. B:

……………………………………………………………………………………

C:……………………………………………………………………………………

[3]

(ii) Explain how the phospholipids molecules form a double layer in a cell

membrane.

…..

……………………………………………………………………………….….

…………………………………………………………………………………

…………………,……………………………………………………………[2]

(b) Cell membranes also contain protein molecules. Give two functions of these proteins molecules.

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…..……………………………………………………………………………….….

……………………………………………………………………………………

……………………………………………………………………………………

…[2]

(c) Explain why Na+

and K +

cannot pass freely across the phospholipids bilayer.…..……………………………………………………………………………….….

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……………………………………………………………………………………

…[2]

(d) Suggest one possible function of the carbohydrate chains attached to the surface of the membrane.

……………………………………………………………………………………

……………………………………………………………………………………

…[1]

4. The diagram below is a diagram of a cell from the epithelial lining of mammalian

intestine.

(a) Name the structures labeled D and E .

D: .…………………………………………………………………………………

E : …………………………………………………………………………………

[2]

(b) Explain the functional relationship between the structures A, B and X .

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…..……………………………………………………………………………….….

………………………………………………………………………………………

…..……………………………………………………………………………….….

……………………………………………………………………………………

……………………………………………………………………………………

…[3]

(c) Outline the role of organelle C in the metabolism of the cell.

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……………………………………………………………………………………

…[3]

(d) Give two differences between prokaryotic and eukaryotic cells

…..……………………………………………………………………………….….

……………………………………………………………………………………

……………………………………………………………………………………

…[2]

Prepared by, Checked by, Approved by,

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…………………………. ………………………….. ………………………..

Lim Lock Leng Norizan Abd Latiff Suryani bt Ismail

Ketua Panitia Biologi Ketua Bidang Sains & Matematik Penolong Kanan

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Biology PK2 L6 2010