Science Skills Review

General Units of Measurement A measurement has two parts: a number and a unit. A unit is a standard amount used to measure something.

Types of Measurements

Length The distance between two points Unit: Meter (m), Centimeter (cm) Millimeter (mm) Hint: position object at 0 on the ruler or meter stick Hint: make sure to use the metric side of the ruler!

Mass Amount of matter (substance) in an object Measure using a balance Units: Grams (g)

Units for Mass Grams (g) Tool Electronic Balance

Area Amount of surface within a set boundary (Length x Width) Units: Meters Squared (m2) or Centimeters Squared (cm2)

The amount of space a substance occupies; gas, liquid or solid Volume The amount of space a substance occupies; gas, liquid or solid

Units for Volume Tools Liter (L); Millimeters (mL) Graduated cylinder (Preferred); Beaker; Flask

Curved upper surface of a liquid in a tube Meniscus Curved upper surface of a liquid in a tube Meniscus

What is the volume?

Practice reading volume on a graduated cylinder Find the scale of the graduated cylinder. Read at the bottom of the meniscus. 8.45 mL

Practice reading volume on a graduated cylinder Find the scale of the graduated cylinder. Read at the bottom of the meniscus. 32.5 mL

Practice reading volume on a graduated cylinder Find the scale of the graduated cylinder. Read at the bottom of the meniscus. 33.5 mL

Density Amount of matter that occupies a given space (mass/volume) Units: g/mL

Time Interval between two events Units: Seconds (s)

Measure of the warmth or coldness of an object. Temperature Measure of the warmth or coldness of an object.

Qualitative Observations vs. Quantiative Measurements Qualitative observations: Descriptions in words of what is being observed. They are based on some quality of an observation, such as color, odor, or texture.

Steps of the Scientific Method

The question being addressed 1. Problem The question being addressed

The possible answer to the question 2. Hypothesis Testable prediction The possible answer to the question

*Hypothesis (If – Then Statement) Most of the time a hypothesis is written like this: "If [I do this], then [this] will happen

A series of steps that are taken to try to support the hypothesis. 3. Experiment A series of steps that are taken to try to support the hypothesis.

The information which is collected when the experiment is run 4. Analyze Data The information which is collected when the experiment is run

A decision reached about the hypothesis after examining the data. 5. Conclusion A decision reached about the hypothesis after examining the data. PROVE Data supports or does not support the hypothesis!

6. Publish Data Share data and conclusions with the scientific community; if something new discovered.

Scientific Method Terms: Independent Variable Explanation: Something that is changed by the scientists (experimenter); Look for the word “different” What is different? What is manipulated?

Scientific Method Terms: Dependent Variable Explanation: The variable that is measured in an experiment; the data that is collected What is measured? What are you collecting data on?

Scientific Method Terms: Control Explanation: The variable that is not changed or manipulated in an experiment; serves as the standard for comparison What experiment do we know the outcome?

Scientific Method Terms: Constant(s) Explanation: The components that are kept the same for every experiment Experiment: The affect of temperature on fish activity What stays exactly the same?

Graphing

What is a Graph? A diagram showing the relationship between (typically) two variables, each measured along a pair of axes (x and y)

Three main graphs used in Biology 1. Bar Graph: Comparisons between different groups or to track changes over time. nces.ed.gov

How to Graph???

a. Identify the Variables Dependent - What is measured Independent – What is varied/changed pH of Water Number of Tadpoles Dependent: Number of Tadpoles Independent: pH of Water

b. Label axis The dependent variable goes on the y-axis Include Units When Appropriate The independent variable goes on the x-axis

Number of Tadpoles pH of Water

c. Determine the axis scale Spread the graph out to the MOST available space. Take up ALL the graph paper. You don’t ALWAYS have to start from zero. Find the lowest value and go down a bit.

d. Plot data points pH of Water # of Tadpoles 8.0 45 7.5 69 7.0 78 6.5 88 6.0 43 5.5 23

e. Connect the data points using a ruler

f. Title the graph The affect of _______ (IV) on _______ (DV)

Characteristics of Life

1. Living things are made up of cells

A cell is the basic building block of all living things

Organisms can be UNICELLULAR or made up of one cell

Organisms can be MULTICELLULAR or made up of MANY cells Circles = Cells

2. Living things reproduce

Type of Reproduction: Asexual One parent “Grows” an identical offspring When offspring is developed, it separates from parent Genetically IDENTICAL

Type of Reproduction: Sexual Two parents A parent contributes sperm and the other an egg; fertilization creates a new offspring with DNA from both parents Genetically DIFFERENT

3. Living things have DNA

What is DNA? It is an organisms genetic make-up OR a genetic blueprint with the directions for the traits (characteristics) that make all organisms unique.

4. Living things grow and…..

…… Develop

What is the difference between growth and development? Growth is the increase in size of an organism Ewwwwww….

Development is a transformation (change) into a different stage often for improvement

5. Living things obtain materials (food) to make energy

What is metabolism? All chemical changes that take place in a cell or an organism to produce energy and basic materials needed for important life processes

Organism can feed using two methods: Autotroph Organisms make their own food in their cells - automatically

Organism can feed using two methods: Heterotroph Organisms cannot make their own food in their cells – need to eat/consume

6. Living things respond to stimuli in their environment When you touch a hot stove, you pull your hand away pretty quickly. IT HURTS!

External Stimulus A stimulus that occurs OUTSIDE of an organism that causes a response; For example – a dog with a shock collar.

Internal Stimulus A stimulus that occurs inside of an organism. For example, if you have hunger pains, you eat!

7. Living things maintain a stable internal environment Organism maintain a constant/stable internal environment For example: Our bodies react when too cold or hot

What is homeostasis? The process of keeping the internal environment of the body stable while the outside world changes

8. Living things can adapt to their environment Organisms have the ability to change over a period of time in response to the environment. The BEST adapted will survive and pass traits on to offspring