Human Biology Unit 1 questions

Which of the following are components of DNA?

• Deoxyribose, uracil and phosphate

• Ribose, adenine and guanine

• Deoxyribose, phosphate and adenine

• Ribose, thymine and cytosine

Which of the following is the function of transfer RNA (tRNA)?

• Transporting amino acids to a ribosome

• Coding for the order of amino acids

• Transcription of the DNA

• Translation of the DNA

The base sequence for the same length of DNA before and after a gene

mutation was as follows:

Before mutation: ATT TCC GTT ATC CGG

After mutation:

ATT CCG TTA TCC GGA

Which type of mutation took place?

• duplication

• deletion

• substitution

• inversion

The statements below show some of the stages in the production of human

insulin from genetically modified bacteria.

1.DNA for insulin inserted into plasmids

2. Bacteria cloned

3. Plasmids inserted into bacteria

4. DNA for insulin cut out using restriction enzyme

Which of the following shows the correct sequence of steps in the process?

• 2-1-4-3

• 4 - 2-3-1

• 4-1- 3-2

• 2-3 4 1

Which of the following enzymes is used to join together pieces of DNA?

• ligase

• DNA polymerase

• protease

• restriction enzyme

Which of the following cell processes needs a source of metabolic energy?

• diffusion

• osmosis

• respiration

• active transport

How does denaturing by heat prevent an enzyme from working?

• By providing kinetic energy to the substrate molecules

• By preventing the substrate from binding with the active site

• By preventing the products from leaving the active site

• By increasing the optimum temperature for the enzyme

Enzymes increase the rate of a reaction. Consider the following statements

about the 'lock and key' model of enzyme action:

1 The reaction can only take place in the active site.

2 The active site is the 'key' to the substrate lock.

3 The enzyme is unable to take part in further reactions after the substrate has

left the active site.

4 When the substrate enters the active site, the energy needed to start the

reaction is reduced.

Which of the statements is/are true?

• 1 and 2

• 3 and 4

• 2 and 3

• 4 only

Which of the following is not an advantage of using an immobilised enzyme?

• The enzyme can be collected with the products.

• The enzyme is less affected by changes in pH

• The enzyme is more stable at high temperatures.

• The enzyme can be re-used.

A bag made of Visking tubing contains a 5% solution of sucrose. It is placed in

a beaker containing a 10% solution of sucrose. Which of the following will take place?

• More water will enter the Visking tubing than leaves it and the volume of the

  tubing will increase

• More water will leave the Visking tubing than enters it and the volume of the

  tubing will decrease

• There will be no net movement of water and the volume will not change

• At first the volume of the Visking tubing will increase, but it will then

  decrease as pressure builds up in the bag

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