Unit 3 - Investigative Biology

Question 1

Name the stages of the scientific cycle

Answer 1

Observation; build a hypothesis; experimental design; gathering recording and analysis of data; evaluation of results and conclusions; revising hypothesis where necessary

Question 2

What is a null hypothesis?

Answer 2

It propeses there will be no statistically significant effect as a result of the experimental treatment

Question 3

Name common methods of sharing original scientific findings

Answer 3

Seminars, talks, posters at conferences and publishing in academic journals

Question 4

What does peer review mean?

Answer 4

When specialists with expertise in the relevant field assess the scientific quality of submitted research and make reccomendations on its suitabilty for publication

Question 5

What are review articles?

Answer 5

They summarise current knowledge and recent findings in a paticular field

Question 6

What are the 3 Rs used in animal studies?

Answer 6

Replacement, reduction and refinement

Question 7

What ethics are involved in human studies?

Answer 7

Informed consent, right to withdraw and confidentiality

Question 8

How can the reliabilty of an experiment be increased?

Answer 8

Replicating the experiment to reduce the chance for dishonesty or the deliberate missuse of science

Question 9

Define validity

Answer 9

Variables are controlled so that any measured effect is likely to be due to independent variable

Question 10

Define reliability

Answer 10

Consistent values in repeats and independent replicates

Question 11

Define accuracy

Answer 11

Data, or means of data sets, are close to the true value

Question 12

Define precision

Answer 12

Measured values are close to each other

Question 13

What is a piloty study used for?

Answer 13

To plan procedures, assess validity and check techniques as well as figure out the number of repeats required to give a representative value

Question 14

What is an independent and dependent variable?

Answer 14

Independent - variable that is changed
Dependent - variable being measured and observed

Question 15

What is a drawback of simple experiment?

Answer 15

Findings may not be applicable to a wider setting

Question 16

What is a multifactorial experiment?

Answer 16

An experiment with a combination of more than one independent variable or combination of treatments

Question 17

Define confounding variables

Answer 17

Variables beside the independent variable which may affect the dependent variable

Question 18

What is a randomised block design?

Answer 18

When blocks of treatment and control groups are randomly distributed in such a way that the influence of confounding variables is likely the same across all treatments and control groups

Question 19

Why are controls used?

Answer 19

Used for comparision with the results of treatment groups

Question 20

What are negative and positive controls?

Answer 20

Negative - provides results in the absence of treatments
Positive - included to check that the system can detect a positive result

Question 21

What is placebo effect?

Answer 21

A measurable change in the dependent variable as a result of a patient’s expectations, rather than changes in the independent variable

Question 22

Define in vitro and in vivo

Answer 22

In vitro - performing a given procedure in a controlled environment outside living organism
In vivo - experiement using whole, living organism

Question 23

What determines an appropriate sample size?

Answer 23

The extent of natural variation within a population

Question 24

Describe a representative sample

Answer 24

A representative ample should share the same mean and the same degree of variation about the mean as the population as a whole

Question 25

Define random sampling

Answer 25

Members of a population have an equal chance of being selected

Question 26

Define stratified sampling

Answer 26

The population is divided into categories that are then sampled proportionally

Question 27

Define systematic sampling

Answer 27

Member of a population are selected at regular intervals

Question 28

How can the reliabilty of measuring instruments or procedures be tested?

Answer 28

Repeated measurements or readings of an individual datum point. The variate observed indicates precision but not neccessarily accuracy

Question 29

Why should independent replication be carried out?

Answer 29

Overall results can only be considered reliable if they can be achieved consistently

Question 30

Describe quantative and qualitative data

Answer 30

Quantative - can be measured and given numerical values Qualitative - subjective and descriptive

Question 31

Define ranked data

Answer 31

When data recorded is placed into hierarchical order

Question 32

Define positive and negative correlation

Answer 32

Positive - exists when an increase in one variable is accompanied by an increase in the other Negative - exists when an increase in one variable leads to a decrease in the other variable