LIFESCI 2A03 Final Notes

What is the definition of Science?

Science is the pursuit and application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence.

What are the characteristics of science?

1. Based on empirical knowledge 2. Provides rational/natural explanations 3. Testable 4. Repeatable and reproducible 5. Involves observation and experimentation 6. Generality of principles.

What is empirical knowledge?

Knowledge based on evidence from observation and experimentation.

What is a hypothesis?

A tentative explanation to a research question that is testable and leads to predictions.

What is the difference between correlation and causation?

Correlation is an association between two variables that change together predictably, while causation indicates that one event is the result of another event.

Define positive correlation.

A positive correlation occurs when one variable increases, and the other variable also increases.

How does a directional research hypothesis differ from a nondirectional hypothesis?

A directional hypothesis states the expected direction of the association (positive or negative), while a nondirectional hypothesis does not specify a direction.

What is the null hypothesis (H0)?

The null hypothesis implies no relationship between the variables being studied.

What is the purpose of randomization in experimental design?

Randomization prevents systematic bias by ensuring uncontrolled variables are equally distributed across experimental conditions.

What is a positive control in an experiment?

A positive control is a group that receives a treatment with a known expected effect to demonstrate that the experimental setup works.

How do you determine when to reject or fail to reject a hypothesis?

If the p-value is less than the significance level (α), then reject the null hypothesis; otherwise, fail to reject it.

What is the significance of controlling for confounding variables?

Controlling for confounding variables helps isolate the effects of the independent variable on the dependent variable, leading to more accurate results.

What are the main types of stem cells?

1. Embryonic stem cells (ESCs) 2. Adult tissue stem cells (ASCs) 3. Induced pluripotent stem cells (iPSCs).

What is the Hayflick limit?

The Hayflick limit is the number of times a normal somatic human cell can divide before cell division stops, associated with telomere shortening.

What are neoblasts?

Neoblasts are pluripotent stem cells found in planaria that are responsible for tissue regeneration and homeostasis.

What is the role of the SC niche?

The SC niche is a local tissue microenvironment that maintains and regulates stem cells through extrinsic stimuli.

Explain what is meant by 'scientific method as an iterative process'.

The scientific method is considered iterative because its steps can be repeated and refined based on outcomes and newly gathered information.

What is the importance of scientific knowledge?

Scientific knowledge identifies new phenomena, solves scientific problems, develops inventions, and provides a basis for policies in government and industry.

What does it mean for a hypothesis to be falsifiable?

A hypothesis is falsifiable if it can be proven wrong through experimentation or observation.

What are the steps of the scientific method?

1. Determine the problem/question 2. Formulate a hypothesis 3. Formulate predictions 4. Test predictions 5. Analyze data 6. Draw conclusions 7. Communicate results.

What is the role of statistical analysis in research?

Statistical analysis helps to interpret data, evaluate the significance of results, and draw conclusions based on numerical evidence.