Question

1. Kashif wants to investigate the effect of different factors on the activity of salivary amylase. He designs an experiment in order to reach a conclusion.
The MOST appropriate first step for Kashif to undertake is to
A. Test a variable.
B. Put forward a theory.
C. Formulate a hypothesis to test.
D. Gather and set up the required material.
2. According to the scientific method of solving a biological problem, which of the following cannot be opposed or rejected?
A. Mass-flow hypothesis
B. Mendel’s laws of inheritance
C. Darwin’s theory of evolution
D. A student’s daily observations
3. A scientist investigates the effect of increasing calcium nitrate concentration on the height of two different species of plants at constant temperature. He then organises the data in graphical form.
While drawing the graph, which quantity must he take on y-axis?
A. Temperature
B. Height of plants
C. Species of plants
D. Concentration of calcium nitrate
4. A student extracts saliva (pH 7) from the mouth of a mammal, mixes it with some fine pieces of bread and keeps the mixture at 32°C. After three hours, a positive re
sult is obtained, i.e. the pieces of bread disappear from the mixture.
A positive result can also be obtained by
A. Repeating the procedure at 36°C.
B. Conducting the experiment at pH 2.
C. Using distilled water instead of saliva.
D. Repeating the experiment after boiling saliva.

5. A theory becomes a law when it is
A. Used to form deductions.
B. Followed by further research.
C. Tested on both animals and plants.
D. Universally accepted by the scientists.
if i got a correct ans i will mark as briliant

Answer 1

Answer:

Measure the time taken for amylase to completely break down starch, by withdrawing samples at 10 second intervals and noting the time at which the solution no longer gives a blue-black colour with iodine solution (but the iodine solution remains orange). Use buffers to provide solutions at different pHs. Calculate the rate of this enzyme controlled reaction by calculating

Answer 2

Answer:

1.gather and set up the required material

2. A student's daily observation

3. Concentration of calcium nitrate

4.The bread packed in the packet is composed of starch. Iodine gives blue color when it reacts with raw bread due to the presence of starch in it.

5. Once a theory has been tested thoroughly and is accepted, it becomes a scientific law