Scientific Method

Question 1

Biology

Answer 1

Study of living organisms

Question 2

Different areas of biology

Answer 2

Botany - study of plants
Microbiology - study of small living things, such as bacteria
Zoology - study of animals
Ecology - study of the environment
• Genetics - study of genes
Biochemistry - study of chemical processes that take place in organisms
Anatomy - study of organs, muscles, structure of organisms
Cytology - study of cells
Immunology - study of immune systems of organisms
Marine biology - study of organisms in the ocean

Question 3

The scientific method

Answer 3

a series of investigations to identify problems and explain these by means of carrying out experiments

Question 4

Process of scientific method

Answer 4

Observation
Hypothesis
Experiment
Data
Conclusion
Theory
Principle

Question 5

Observation

Answer 5

Noting or registering a phenomenon

Question 6

Hypothesis

Answer 6

An educated guess

Question 7

Experiment

Answer 7

A test to prove or disprove the hypothesis

Question 8

Data

Answer 8

Information gathered from testing

Question 9

Conclusion

Answer 9

Results of testing are summarised

Question 10

Theory

Answer 10

A hypothesis that has been proven by experiments a number of times

Question 11

Principle

Answer 11

a theory that has been proven by experiments many, many times

Question 12

Osmosis experiment Hypothesis

Answer 12

Hypothesis: The visking tube has a more concentrated solution and so water moves across the membrane by osmosis.

Question 13

Osmosis experiment control

Answer 13

Control: One of the tubes has water in it.

Question 14

Osmosis experiment variable

Answer 14

Variable: One of the tubes has sucrose solution in it.

Question 15

Osmosis experiment data

Answer 15

Data: Mass of both tubes is measured and recorded before and after the experiment.

Question 16

Osmosis experiment conclusion

Answer 16

Conclusion: Water moves into the visking tube with the sucrose solution by osmosis.

Question 17

Limitations of the scientific method

Answer 17

• The extent of our knowledge. (Forming a hypothesis and designing an experiment depends on the amount we know relating to our observations.)
Our ability to understand the results (If the results of an experiment are interpreted
wrongly, then faulty conclusions and hypotheses will be drawn.)
Accidental discoveries (New insights are often discovered accidentally which have contributed to the development of scientific thinking.)

Changes in the environment (Scientific methods may only apply to living things at one particular time. As living things are constantly evolving, hypotheses must constantly be changed. For example, global warming over the last several decades has impacted on plant and animal behaviour patterns.)
The basis of investigation (If an investigation is badly designed or improperly carried out it will not yield results that are as valid as they should be)

Question 18

Where results can be published

Answer 18

Internet
Scientific journal
Newspapers/magazines

Question 19

Random selection and why important

Answer 19

Random selection: To avoid bias. This is so that we don’t accidentally select a certain type of sample, as this will mean the results are influenced by the factor that is selected. If random samples are taken, then we can ensure that the experiment applies to all of the population, and the experiment is fair.

Question 20

Replication and why important

Answer 20

Replication (repeating the experiment): To verify your results. A replicate is a repeat of an experiment. If it can be repeated, the results can be shown to be always true and not caused by some unknown influence.

Question 21

Large sample size and why important

Answer 21

Use a large sample size: To ensure that the result was not only representative of a small amount of organisms. The larger the sample size, the less risk there is that the results are due to individual differences, rather than being caused by the factor that is being investigated.

Question 22

Double blind testing and why important

Answer 22

Double blind testing (an experiment in which neither the tester nor the subject knows what treatment a given subject is receiving. In essence, it’s “anonymised” - but there is a record of who received what in the background. This way the tester cannot influence the experiment by consciously or unconsciously giving clues to the subject or otherwise. A placebo is a “fake” drug, or intervention, used in an experiment to set up a control): To avoid bias

Question 23

Ways of keeping experiments fair

Answer 23

Random selection
Replication
Large sample size
Double blind testing

Question 24

How to set up an experiment:

Answer 24

Variable This is what is going to change in your experiment. In almost all experiments, only one variable is tested, and all other variables are kept constant (in practice, this isn’t always possible, but it is desired because then it’s possible to know that it is the variable that made the difference to the outcome).

Control: Set up a comparison for your experiment. A control is used to provide a standard against which the variable can be judged. There should only be one variable between the control and the actual experiment.

Plan & design: Choose the reagents and instruments needed for the experiment and the method that will be used. Use the steps in the scientific method.

Safety procedures: Ensure that your experiment is safe by using precautions such as wearing gloves, wearing goggles, wearing a lab coat, tying up long hair, reporting accidents

Question 25

Sources of error in experiments:

Answer 25

Miscounting
Misidentification of a substance or organism
Bias- eg sample not random

Question 26

Ethical Issues:

Answer 26

Ethics refers to the concept of whether something is right or wrong. There are sometimes arguments as to whether the application of a scientific method is good or bad, such as cloning animals, or using placebo where it is likely that the active compound could make a difference to survival

Question 27

Why is it important that scientists publish the results of their research?

Answer 27

So that other people can benefit from their research and continue the research further, aiding further scientific discovery

Question 28

How can scientists avoid bias in scientific experiments?

Answer 28

Repeat the experiment a number of times and ensure that they get the same result each time

Question 29

What is the purpose of replicates in scientific experimentation?

Answer 29

To ensure result is not biased

Question 30

What is meant by the term hypothesis?

Answer 30

A possible untested explanation for observation

Question 31

In relation to the scientific method, explain each of the following.
(i) Experiment:
(i) Theory:

Answer 31

(i) Experiment: This is designed to test the hypothesis, and will either support or contradict it.
(i) Theory: This is a hypothesis that has been supported by many different experiments.

Question 32

Scientists investigated the effect of a certain mineral on the growth of wheat. Use your knowledge of biology and laboratory procedures to answer the following questions. Suggest a reason why the seeds used were all taken from one parent plant.

Answer 32

So that all results will have the same genetic make up.

Question 33

Answer parts i) and ii) in relation to the scientific method.
(i) What is a hypothesis?

Answer 33

A hypothesis is an educated guess based on observations.

Question 34

(ii) Why is a control normally used when carrying out an experiment?
.

Answer 34

A control is used to provide a standard against which the actual experiment can be judged

Question 35

(b) Why is a control especially important in biological investigations?

Answer 35

It is important as we then have a standard against which the actual experiment can be judged.

Question 36

If a scientist wished to determine the effect of a certain herbicide on weed growth she would include a control in the investigation. Suggest a suitable control in this case.

Answer 36

Water

Question 37

The use of replicates is an important aspect of scientific research. What, in this context, are replicates?

Answer 37

A replicate is a repeat of an experiment which can verify if it is valid.

Question 38

(e) Suggest where a scientist may publish the results of her investigations

Answer 38

They can publish them in journals, magazines, newspapers, the internet and on TV.

Question 39

Explain each of the following terms in relation to the scientific method.
(a) Hypothesis:

(b) Control:

(c) Data:

(d) Replicate:

Answer 39

(a) Hypothesis:
This is an educated guess based on an observation.
(b) Control:
This is used to provide a standard against which the actual experiment can be judged.
(c) Data:
Data consists of measurements, observations and information gathered from experiments.
(d) Replicate: A replicate is a repeat of an experiment, which can verify its validity.