Practice of Science-Part 1

Practice of Science (Part 1)

Types of Investigations & Hypotheses

• Involves testing dependent & independent variables.

• Establishes cause and effect relationship.

• Has a control group or experimental group.

• Testing the effect of...

• Example:Testing to see how the height effects how far a marble rolls.

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​What is a Experimental Investigation?

• Clear questions drive the investigation to develop descriptive findings using collected data.

• Not a complete scientific method. Hypothesis or prediction is not necessary.

• Used to describe, list, observe or identify

• Example: Observing cells under a microscope and diagramming observations.

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What is a Descriptive Investigation?

• Involves collecting data on different organisms, objects, features or collecting data under different conditions to make a comparison.

• Can include a hypothesis and scientific variables, but no control group.

• Looking for patterns or trends by comparing similarities & differences.

• Example: comparing two types of leaves to see which one has a greater rate of transpiration.
  

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What is a Comparative Investigation?

Multiple Choice

In science class, Michalea was studying the vascular system of plants. She cut the bottom off a stalk of celery and then placed the celery in colored water. She left the celery in the cup for 24 hours. When she observed the celery, she noticed that there were colored tubes in the celery stalk, which she knew was the xylem tissue. She cut off a piece of the celery and observed it under a dissecting microscope and drew her observations.

• Experimental Investigation

• Descriptive Investigation

• Comparative Investigation

Multiple Choice

In science class, Jackson learned that the underside of many leaves contained structures called stomata. Water vapor and other gases exit the plant through the stomata. Jackson wondered if the leaves of a hibiscus plant or the leaves from an ivy plant had more stomata. He used clear fingernail polish to paint a 2 cm square area on the underside of each leaf. He then placed clear packing tape on each painted area and lifted the tape and removed an impression of the leaf. He placed the clear packing tape on microscope slides and then observed the impressions and counted the number of stomata on each leaf.

• Experimental Investigation

• Comparative Investigation

• Descriptive Investigation

Multiple Choice

Robert was asked to determine how temperature affects enzyme activity. Potatoes placed in hydrogen peroxide were used as a source of the enzyme catalase. Robert tested the potatoes under three different conditions: potatoes at room temperature, potatoes that had been placed in an ice bath, and potatoes that had been placed in boiling water. The potatoes at room temperature served as his control group. He counted the bubbles that formed to determine enzyme activity.

• Experimental Investigation

• Comparative Investigation

• Descriptive Investigation

A Hypothesis is a testable/measurable explanation that leads a scientific investigation or scientific experiment.

​What is a hypothesis?

Uses the If, Then, Because Statement

If (I do this...) then (This is what I think will happen) because (This is why I think that).

If (Independent Variable) then (Dependent Variable) because (Reasoning).

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How do I write a Hypothesis?

Multiple Choice

Which statement BEST describes a HYPOTHESIS?

• A testable explanation

• An educated guess

• A prediction

• An inference

Multiple Choice

True or False: A hypothesis must be stated in a way that is testable.

• True

• False

Multiple Choice

Is this a Good Hypothesis?

If I wash clothes in three different types of laundry detergents, then the most expensive laundry detergent will remove the greatest percentage of the stain because obviously the most expensive detergent will work the best.

• Yes, because the reasoning is scientific

• No, because the reasoning is not scientific

Multiple Choice

Is this a Good Hypothesis? 

If I grow pea plants in 3 different types of soil (sand, clay and top soil), then the pea plants growing in the top soil will grow the tallest because it contains the most nitrogen, which is a nutrient required for plant growth? 

• Yes, because it has an independent variable and dependent variable

• No, because their are no variables.

Multiple Choice

Is this a Good Hypothesis?

If I put my hand in cold and warm water, then the fingers in warm water will wrinkle faster because the warm water will dissolve the oils on the skin faster and therefore the cells can begin to absorb the water more quickly. 

• Yes, because its testable

• No, because its not testable

Let's Practice!

Multiple Choice

Will a construction paper airplane fly faster than an airplane made from notebook paper? Choose the best hypothesis.

• If I make a paper airplane from notebook paper, then it will fly faster than an airplane made from construction paper.

• Notebook paper is fast. 

• I love paper airplanes.

• I think the construction paper airplane will fly faster.

Multiple Choice

A hypothesis statement should always include these two words. 

• Where and how

• Who and what 

• Near and far

• If and then

Multiple Choice

This includes a control group, independent variable and dependent variable.

• Descriptive Investigation

• Comparative Investigation

• Scientific Experiment

Multiple Choice

Counting the number of leaves on a plant is an example of ____________?

• Descriptive Investigation

• Comparative Investigation

• Scientific Experiment

Multiple Choice

Looking for similarities between 2 different plants describes a ____________?

• Descriptive Investigation

• Comparative Investigation

• Scientific Experiment

Multiple Choice

Comparing the growth of pants given different amounts of fertilizer to a plant that was not given any fertilizer is an example of a _____________?

• Descriptive Investigation

• Comparative Investigation

• Scientific Experiment

Multiple Choice

 An organized procedure to study something under controlled conditions is called:

• theory

• experiment 

• observation

• hypothesis

Multiple Choice

Students identify types of organisms eaten by a praying mantis.

• Descriptive Investigation

• Comparative Investigation

• Scientific Experiment

Multiple Choice

Students see how bacteria grows when different types of antibiotics are added compared to bacteria grown without antibiotics. This describes a __________.

• Descriptive Investigation

• Comparative Investigation

• Scientific Experiment

Multiple Choice

Meredith completed an investigation involving earthworms. She placed a worm on a moist paper towel and carefully marked the position of the worm on the paper towel. She placed a cardboard box over the worm and paper towel and left it undisturbed for 10 minutes. She removed the box and noted that the worm had not moved from its original position. She then took a flash light and shined it on the worm for 10 minutes. After the end of the 10 minutes she measured the distance the worm moved in cm.

• Descriptive Investigation

• Comparative Investigation

• Scientific Experiment

Multiple Choice

Students measure how changing the amount of salt in the water affects plant growth in an aquarium.

• Scientific Investigation

• Comparative Investigation

• Scientific Experiment

Multiple Choice

 A testable idea or explanation that leads to scientific investigation based on prior knowledge is known as: 

• theory

• experiment 

• observation

• hypothesis