Question 1

Lactose is formed by a reaction between glucose and galactose, both of which have the chemical formula C6H12O6.

Which option shows the correct chemical formula for lactose?

  A  

C12H22O11


  B  

C12H24O12

  C  

C12H26O13

  D  

C12H22O12

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Question 2

Carbohydrates, such as starch, are made from monosaccharides joined together.

Which bond joins monosaccharides together?

  A  

ester

  B  

glycosidic

  C  

peptide

  D  

phosphodiester

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Question 3

What can occur during condensation of carbohydrates?

  A  

a disaccharide is produced from monosaccharides


  B  

glycosidic bonds are broken

  C  

molecules of water are used up

  D  

monosaccharides are produced

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Question 4

What occurs when sucrose is broken down to monosaccharides?

  A  

condensation of reducing sugars releasing water

  B  

condensation of reducing sugars using water

  C  

hydrolysis, releasing reducing sugars and releasing water

  D  

hydrolysis, releasing reducing sugars and using water

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Question 5

X and Y show the structures of two hexose sugars.

Which statement is correct?

  A  

X is found in amylopectin


  B  

X is found in amylose


  C  

Y is found in cellulose

  D  

Y is found in glycogen

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Question 6

A sample of milk is tested with Benedict’s solution. After boiling, a yellow colour is observed.

Which conclusion is correct?

  A  

a high concentration of glucose is present

  B  

a low concentration of sucrose is present

  C  

no reducing sugars are present

  D  

reducing sugars are present

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Question 7

Which carbohydrate gives a brick red colour when boiled with Benedict’s solution?

  A  

cellulose


  B  

fructose

  C  

glycogen

  D  

sucrose

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Question 8

Tests were performed on samples from a mixture of biological molecules.

When iodine in potassium iodide solution was added to a sample, the mixture turned black.

When the biuret test was carried out on another sample, the mixture turned purple.

Which biological molecules were in the mixture?

  A  

amylase and starch

  B  

cellulose and starch

  C  

phospholipid and cellulose


  D  

starch and phospholipid

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Question 9

The structure of a biological molecule is shown below.

Which option correctly describes the molecule?

  A  

hexose monosaccharide glucose


  B  

hexose monosaccharide ribose


  C  

pentose monosaccharide glucose


  D  

pentose monosaccharide ribose


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Question 10

An unknown solution of a single sugar was tested. After Benedict's test for reducing sugars, the colour observed was blue. After Benedict's test for non-reducing sugars, the colour observed was brick red. 

Identify the unknown sugar.

  A  

fructose

  B  

lactose

  C  

sucrose

  D  

glucose

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Question 11

Why may fish living in ponds survive temperatures below 0°C in winter?

  A  

fish body tissues produce an enzyme which prevents blood from freezing

  B  

the ice on the pond surface insulates the water in the pond

  C  

the plants in the pond help to keep the water temperature above 0°C

  D  

the rocks in the pond warm up during the day and heat the water

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Question 12

Polar molecules form hydrogen bonds with each other.

Which properties of water result from its molecules being polar?

1 - good solvent

2 - high specific heat capacity

3 - high surface tension

4 - cohesive

  A  

1, 2, 3, and 4

  B  

1, 2, and 3 only

  C  

1, 2, and 4 only

  D  

3 and 4 only

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Question 13

Which properties of water are important for transport in xylem?

1 - cohesion

2 - adhesion

3 - high energy requirement for evaporation

4 - good solvent properties

  A  

1, 2, and 4

  B  

1 and 4 only

  C  

2, 3, and 4

  D  

2 and 3 only

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Question 14

A student wrote the following statement:

‘Water is polar because the oxygen side of the molecule is slightly positive in charge.’

Which option explains why this statement is not correct?

  A  

water must be non-polar because it can dissolve non-polar molecules like carbon dioxide

  B  

water must be non-polar because it can pass through the fatty acid tails of phospholipids


  C  

the oxygen side of the molecule is slightly negative in charge, not positive

  D  

water is not polar, it is charged


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