Name Student:

Biology Standard LevelPaper I & II

1 hour 30 minutes

Tuesday 06 December 2011

INSTRUCTIONS TO CANDIDATESDo not open this examination paper until instructed to do so. Answer all the questions.For each question, choose the answer you consider to be the best and indicate your choiceAnswer all in the spaces provided. Use pen only. Use clear handwriting

Paper I

Paper II

Paper I

1. The t-test is used to test the statistical significance of a difference. What is that difference?

A. Between observed and expected results

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B. Between the means of two samples

C. Between the standard deviation of two samples

D. Between the size of two samples

2. What does the following scatter graph show?

A. No correlation between these variables

B. Strong positive correlation between these variables

C. Strong negative correlation between these variables

D. Weak negative correlation between these variables

3. Which of the following structures are found in all cells?

A. Mitochondria

B. Cell walls

C. Chloroplasts

D. Ribosomes

4. By what process do most bacteria divide?

A. Mitosis

B. Meiosis

C. Conjugation

D. Binary fission

Questions 5 and 6 refer to the following micrograph of an E.coli bacterium undergoing

reproduction.

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5. The scale bar represents 0.5 μm. How long are both cells in total?

A. 5.0x10−6m

B. 5.0x10−9m

C. 2.5x10−6 m

D. 2.5x10−9 m

6. In the diagram what does label X identify?

A. Nucleoid region

B. Chromatin

C. Histones

D. Endoplasmic reticulum

7. The diagram below shows a plasma membrane. What is molecule X?

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A. Cholesterol

B. Peripheral protein

C. Glycoprotein

D. Polar amino acid

8. What is a difference between a cell in the G1 phase and a cell in the G2 phase of the cell cycle?

A. A cell in the G2 phase would be smaller than a cell in the G1 phase.

B. A cell in the G2 phase would have more mitochondria than a cell in the G1 phase.

C. A cell in the G1 phase would have more DNA in its chromosomes than a cell in the G2 phase.

D. DNA replication occurs in the G1 phase but not in the G2 phase.

9. If the haploid number of a species is 14, how many chromatids will there be in metaphase I in a

dividing diploid cell?

A. 7

B. 14

C. 28

D. 56

10. Blood is a water-based transport medium. Which property of water makes it a good transport

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A. High specific heat

B. Transparency

C. Versatility as a solvent

D. It has its greatest density at 4°C

11. What is placed into the uterus after the process of in vitro fertilization (IVF)?

A. Eggs

B. Sperm

C. Embryos

D. Fetuses

12. How does the surface area to volume ratio change with an increase in cell size?

13. How do prokaryotic cells divide?

A. By mitosis

B. By meiosis

C. By budding

D. By binary fission

14. What can the extracellular matrix of cells be made of?

I. Polysaccharide

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II. Glycoprotein

III. Phospholipid

A. I only

B. I and II only

C. II and III only

D. I, II and III

15. During which phase of the cell cycle do chromosomes duplicate?

A. G1

B. S

C. G2

D. Mitosis

16. What is the difference between simple diffusion and facilitated diffusion?

Simple diffusion Facilitated diffusion

17. Which of these processes require mitosis?

A. Embryological development

B. Reducing surface area to volume ratio

C. Maintaining cell size

D. Cell growth

18. Which phase of cell division is photographed in order to make a karyotype?

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A. Anaphase of mitosis

B. Anaphase I of meiosis

C. Metaphase of mitosis

D. Metaphase II of meiosis

19. Which combination of features is found in most plant and animal cells?

A. plasma membrane, lysosome, Golgi apparatus

B. cytoplasm, mitochondria, ribosomes

C. rough ER, nucleus, centrioles

D. plastids, cytoplasm, nucleus

20. During endocytosis, what change will most likely occur in the plasma membrane of a cell?

A. It will form two phospholipid monolayers.

B. It will become electrically charged.

C. It will partially dissolve.

D. It will form vesicles.

Paper II

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1. This is an electronmicrograph of the bacterium Salmonella typhi.

a. Calculate the magnification of the image. [1]

b. State the name and function of this structure. [1]

i. Name: ……………………………………………

ii. Function: ……...………………………………...

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c. State the method by which prokaryote cells reproduce. [1]

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2. Label the diagram. [6]

A

B

C

D

E

F

3. Compare diffusion and osmosis. [2]

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4. What are the names and functions of these parts of the plasma membrane? [5]

The five names and function must be included to receive [5]The diagrams must have the name , otherwise award [3 max]

If you put only the name of structure [1]

5. (a) Define osmosis. [1]

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(b) Outline how transport occurs across membranes by facilitated diffusion. [2]

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(c) Explain how the properties of phospholipids help to maintain the structure of

cell membranes. [2]

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SECTION B

6. (a) Explain how mitosis produces two genetically identical nuclei. [5]

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(c) Outline one therapeutic use of stem cells. [5]

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c. Draw labelled diagrams of the four stages of Mitosis in an animal cell with four chromosomes. [5]

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The four diagrams must have the name of the phase, otherwise award [3 max]The four stages must be included to receive [5]. If correct number of chromosomes is not shown award [4 max]

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¡Enjoy the science!

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