I need help for my biology lab

The Scientific Method BACKGROUND SLIDES FOR LAB 1

The scientific method involves a set of processes to test a question (developed from an observation)

Asking Scientific Questions

Lab Activity

Adapted from :

What drives the day-to-

day work of scientists?

 Investigating, understanding, and developing explanations for how [the earth, the universe, systems, etc.] work.

 Recipes are a formula or procedure for doing or attaining something.

 A recipe for investigation is built from a scientific question.

So how do you come up with a scientific question?

To come up with a scientific question, we must first understand the common elements that define what science is.

Discuss: What is science?

To come up with a scientific question, we must first understand the common elements that define what science is.

Discuss: What is science?

Ultimate Goal: Explain the Natural World

How an introductory biology book defines science:

Science is the experimental, hypothesis-driven investigation of phenomena to elucidate: 1. patterns in nature 2. the processes governing the formation,

maintenance, and changing of those patterns

Where does cause and effect fit in?

Explaining the natural world means using cause and effect!

Answering questions about cause and effect has led to most of the powerful insights offered in science.

Cause and effect are such important ingredients that we have come up with different names for them in different fields of study, but they are all synonyms and mean cause and effect.

Let’s demystify scientific jargon with a synonym game so you can reduce intimidation and let your brain start being creative.

Synonyms for Cause

Synonyms for Effect

Synonyms for Cause Synonyms for Effect independent variable dependent variable

x y driver responding variable

generator f(x) process pattern agent force factor actor

source basis

Remember English grammar? What kind of words are cause and effect?

SUBJECT AND OBJECT

What type of word

connects subjects to

direct objects in a

sentence?

Verb

So let’s think of some verbs that can link all those synonyms for cause and effect.

This is a third ingredient in your question.

Cause, effect, and a verb!

Synonyms for Cause Verbs Synonyms for Effect independent variable dependent variable

x y driver responding variable

generator f(x) process pattern agent force factor actor

source basis

Synonyms for Cause Verbs Synonyms for Effect independent

variable drives dependent variable

x generates y driver causes responding variable

generator regulates f(x) process controls pattern agent increases force decreases factor suppresses actor

source basis

So coming up with your recipe is not so hard.

Formulating a question that supports a recipe for investigating relationships between cause and effect also enables good communication.

Let’s see if we can identify cause and effect in scientists’ titles!

Small group assignment: Evaluate titles from recent journal articles. Identify the type of research described by the title as:

 establishing a cause-and-effect relationship

 something else

Highlight the potential causal agent(s) in yellow (or underline once) and highlight the effect(s) in green (or underline twice).

Scientific Method 7 STEPS

My toaster doesn’t toast my bread. There is something wrong with the electrical outlet.

This Photo by Unknown Author is licensed under CC BY-ND

Everyday example of using the scientific method 1. Observation My toaster doesn’t toast my bread. There is something wrong with the electrical outlet.

2. Question Why doesn’t my toaster work?

3. Hypothesis (answer) something is wrong with the electric outlet

4. Prediction

If something is wrong with the outlet, my coffeemaker also won’t work when plugged into it.

5. Experiment I plug my coffee maker into the outlet.

6. Result My coffeemaker works.

Scientific Method : Beriberi

 In 1887 a strange nerve disease attacked the people in the Dutch East Indies. The disease was beriberi. Symptoms of the disease included weakness and loss of appetite; victims often died of heart failure. Scientists thought the disease might be caused by bacteria. They injected chickens with bacteria from the blood of patients with beriberi. The injected chickens became sick. However, so did a group of chickens that were not injected with bacteria.

Water soluble

Unknown Factor

Beriberi

This Photo by Unknown Author is licensed under CC BY

The power of observation: Dr. Eijkman

 One of the scientists, Dr. Eijkman, noticed something. Before the experiment, all the chickens had eaten whole-grain rice, but during the experiment, the chickens were fed polished rice. Dr. Eijkman researched this interesting case and found that polished rice lacked thiamine, a vitamin necessary for good health.

This Photo by Unknown Author is licensed under CC BY-SA

Sick Sick

Experiment to see if bacteria causes beriberi Test of hypothesis: Control vs. Injected group of chickens

Do the results indicate that the hypothesis should be rejected?

 The hypothesis is rejected because the

Control group, that is the chickens which did not get the injection (bacteria from people infected with Beriberi ) was also infected.

Control group

Injected group

What should be the new hypothesis ? Beriberi must be caused by something else besides bacteria.

So Dr. Eijkman observed that it might be due a nutrient deficiency found in the food intakes of the chicken.

New Hypothesis: Beri Beri is caused by a thiamine deficiency.

How would you test it?

You would want to put half of the chickens on a polished diet (deficient thymine) and half on a whole grain diet (thymine fortified). See if the only half of the chickens gets the beriberi (thymine deficient).

Polished Rice Whole grain Rice

What have you learned?

 Scientific Method

 Questions are the basis for how scientists create the recipe for research, investigation, and experimentation.

 Scientific recipes often have three main ingredients: cause, effect, and verb.

 The creativity in questions simply comes from the novelty of the words placed in those blank statements. If no one has ever looked at that cause before in relation to that effect, it’s new!

 A basic grammar lesson becomes a key for success in forming cause-and-effect scientific questions that can be used for further investigation. Not so hard!