IGCSE Biology Paper-4: Specimen Questions with Answers 132 - 135 of 279

Passage

Plants produce glucose in leaves and convert some of it to sucrose.

Question 132 (7 of 7 Based on Passage)

Edit

Write in Short

Short Answer▾

State the name of the process that plants use to move sucrose from a source to a sink.

Explanation

Translocation of Mineral Ions

Generally, xylem transports inorganic nutrients while phloem transports organic nutrients. But in xylem sap, nitrogen travels as inorganic ions, as well as organic form (amino acids) and related compounds. Small amounts of P and S are passed in xylem as organic compounds. There is also exchange of materials between xylem and phloem.

Question 133

Edit

Write in Brief

One Liner▾

The same experiment was performed with trypsin, another protease enzyme.

Predict the optimum pH for trypsin.

Explanation

The optimum temperature and pH for the trypsin are .

Passage

A biologist performed an experiment to find the optimum pH for the activity of pepsin.

The enzyme activity was measured in four test-tubes. Each test-tube contained a cube of cooked egg white which contains protein.

Fig. shows the four test-tubes.

Solution of Enzyme

The biologist measured the time taken for the complete digestion of the cubes of cooked egg white.

Question 134 (1 of 2 Based on Passage)

Edit

Write in Brief

One Liner▾

The biologist ensured all the cubes of cooked egg white were the same size.

Suggest why.

Explanation

To provide equal surface area for enzymatic activity, it also allows comparison of product with proper experimental validation.

Question 135 (2 of 2 Based on Passage)

Edit

Write in Brief

One Liner▾

Temperature must be controlled in this experiment.

Describe how temperature could be controlled.

Explanation

Using water bath to regulate temperature.

  • Using incubator
  • Solutions must be equilibrated at a specific temperature
  • Using thermometer to check temperature

Developed by: