Which is correct about the organelles listed in the table?

• 1 and 3

• 1 and 4

• 2 and 3

• 2 and 4

The graticule and stage micrometer are used to measure cells. Which is the correct reason why the graticule is calibrated?

• The graticule can be used to make measurements
• The graticule is magnified by the objective lens
• The graticule magnifies the specimen
• The graticule makes comparison

The following are all features of eukaryotic cells (1) chloroplast (2) Golgi apparatus (3) lysosome (4) mitochondrion (5) nucleus. Which of these has a single membrane?

• 1 and 2

• 2 and 3

• 3 and 4

• 4 and 5

A piece of mammalian tissue was homogenised and centrifuged. The biochemical activity of four subcellular fractions was investigated. Which diagram indicates the fraction with maximum synthesis of messenger RNA?

• A

• B

• C

• D

A piece of mammalian tissue was homogenised and centrifuged. The biochemical activity of four subcellular fractions was investigated. Which diagram indicates the fraction with maximum synthesis of ATP?

• A

• B

• C

• D

From the table, which rows show the chemical groups present in the biological molecules listed?

• 1, 2 and 3

• 1, 2 and 4

• 1, 3 and 4

• 2, 3 and 4

Which molecular bonds will be broken by hydrolysis when a molecule of glycogen is converted to glucose

• A

• B

• C

• D

The formation of glycosidic and peptide bonds is responsible for polymerisation in some biological molecules. With reference to the table, which bonds are found in which molecules?

• A

• B

• C

• D

Which is correct for a non-competitive inhibitor of enzyme action? (1) increasing the concentration of the enzyme's substrate will reduce its effect (2) it reduces the activation energy requried for a reaction to take place (3) it reduces the maximum rate of reaction

• 1 only
• 3 only
• 1 and 3 only
• 2 and 3 only

The rate of enzyme-catalysed reactions in human cells is regulated. Which may be involved in such regulation? (1) a change in enzyme concentration (2) a change in substrate concentration (3) inhibition by the final product of the reaction

• 1 and 2 only
• 1 and 3 only
• 2 and 3 only
• 1, 2 and 3