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Notes/Study Guide

PART 1:

Characteristics of Living Things

BIOLOGY is the study of LIFE!

What are the Characteristics of Living Things?

Living things are made up of cells.
Living things reproduce.
Living things have of genetic code (DNA, RNA).
Living things grow and develop.
Living things obtain and use energy.
Living things respond to their environment/stimuli.
Living Things can evolve.
Living things maintain homeostasis (stable internal environment).

Characteristics of Life Video

Let's Dig a Bit Deeper!

Living Things are Made up of Cells...

Cells: collection of living matter enclosed by a barrier that separates the cell from its surroundings; basic unit of all forms of life

Cells can grow, respond to their surroundings, and reproduce. Despite their small size, cells are complex and highly organized. We'll be learning a lot more about cells this year!

Unicellular Organisms: living things made up of ONE cell

Multicellular Organisms: living things made of many cells

Living Things Reproduce...

There are two basic types of reproduction:

Sexual Reproduction: two cells from different parents unite to produce the first cells of a new organism

Asexual Reproduction: the new organism comes from a single parent

Living Things Contain a Genetic Code/Genetic Information...

The inheriting of traits is due to a molecule known as deoxyribonucleic acid aka DNA. With a few exceptions, DNA is the genetic code that determines the inherited traits of an organism We will learn more about DNA structure and genetic inheritance this year!

Living Things Grow and Develop

Every organism has a life cycle, a pattern of growth and change that occurs over and organism's life. All organisms grow during their lifetime. The life cycle of many types of multicellular organisms also involves a process called development. During this process, the cells in an organism not only increase in number but also differentiate (become different).

Living Things Obtains and Use Energy

Metabolism: set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes.

Organisms require energy in order to grow, develop, and reproduce.

Living Things Respond to Their Environment

Organisms live in constantly changing environments. A living thing must find ways to respond to stimuli and other changes.

Stimuli: A “cue” or trigger that causes something to happen (causes a reaction)

Example of Homeostasis : Maintaining body temperature

Living Things Can Evolve

Evolve: change over time

Over a few generations the changes in a group may not seem significant. But over hundreds, thousands, or even millions of years the changes can be dramatic. Living things must be able to change over time aka evolve in order to survive in an ever changing world.

Living Things Maintain Homeostasis

Homeostasis: the process by which organisms keep their internal conditions stable and balanced

If homeostasis is changed in a major way, an organism may not survive.

homeostasis = internal balance

The body must maintain a stable internal environment. Not too high, not too low, but just right.

THINK ABOUT IT!

Explain how the story of Goldilocks and the Three Bears relates to homeostasis.

EXAMPLE: A mnemonic to help remember the 8 characteristics of life.

"(Valley) grads drive really energy-efficient hybrid cars responsibly."

GROWS and develop - (Valley) GRADS

DNA (RNA) - DRIVE

REPRODUCES - REALLY

ENERGY (obtain & use) - ENERGY

EVOLVES- EFFICIENT

maintains HOMEOSTASIS- HYBRID

be made of CELLS- CARS

RESPONDS to the environment - RESPONSIBLY

PART 2:

The Scientific Method

1. The investigator makes an OBSERVATION.

What are observations?

Observation:

A statement of information collected using one of your FIVE SENSES.

Observations are usually the first step in a scientific investigation.

2. The observation leads to a question or questions.

3. The investigator then comes up with a HYPOTHESIS/prediction that is a testable statement that attempts to answer the question.

Do you know what's in a GOOD hypothesis?

The HYPOTHESIS states the objective and usually predicts the outcome. It is a proposed scientific explanation for a set of observations that can be tested.

Hypothesis = Testable Idea/Explanation

IF/THEN statements can make great hypotheses!

4. The hypothesis can be tested with an experiment or research study.

While you are conducting an experiment to test your hypothesis/prediction you should also be collecting DATA along the way.

What exactly is "data"?

Data is information collected through observation and/or experimentation.

There are two major types of data...

Quantitative Data:

quantity, or numbers

OBSERVATIONS you make during a scientific investigation can also be QUANTITIVE.

Examples:

There are three apples.

The item weighed 65 kilograms.

The boy was 135 cm tall.

Qualitative Data:

quality or descriptions

OBSERVATIONS you make during a scientific investigation can also be QUANTITIVE.

Examples:

The fur is soft

The book is green.

The item is not flexible or malleable.

What do I do with the data I collect? Analyze it!

One great tool for analyzing data is graphs!

"When scientists collect data, they are often trying to find out whether certain factors changed or remained the same. Often, the simplest way to do that is to record the data in a table and then make a graph. Although you may be able to detect a pattern of change from a data table a graph of data can make a patter much easier to recognize and understand."

-Prentice Hall Biology

1. Bar Graph

Used for CATEGORICAL data. Data that falls clearly into one category or another.

2. Line Graph

Used for CONTINUOUS data. Data in which you can find a point between two other data points. Helpful when recording data over a period of time.

3. Pie Graph

Pie graphs show parts of a whole. The sum of all parts must add up to 100%.

Remember! To always label your graph! (Title, X-axis, Y-axis)

Don't Let This be You!! Always LABEL your graphs!!

5. Once the data (information) is collected and analyzed, a CONCLUSION can be made that justifies the data. A conclusion is drawn by making INFERENCES about the data collected during an experiment.

The conclusion often leads to more questions to be tested.

What are inferences?

Inference:

An EDUCATED GUESS, based on one or more observations.

A conclusion is drawn by making inferences about the data collected during an experiment.

What do you "Meme" Ms. Hudson ???

Scientific Method Overview

PART 3:

Variables, Constants & Controls

Variable = change

a factor that changes between test groups

Ex: Plant A receives 100 ml of water per day, while Plant B receives only 50 ml. Since the amount of water changes between groups, it is a variable.

Constant = unchanging

a factor that stays the same between test groups

Ex: Plant A and Plant B are planted in 150 mg of soil and receive 8 hours of sunlight per day. Since the amount of soil and sunlight are the same between groups, they are constants.

Mnemonic: I'm a Dr.

Independent variable = manipulated variable = I'm

Dependent variable = responding variable = Dr

Independent variable: The factor I choose to test. I do this differently to the test groups. The variable I deliberately change.

(synonym: manipulated variable)

Dependent variable: The results or data. The variable that is observed and that changes in response to the independent/manipulated variable.

(synonym: responding variable)

Finding Variables on a Graph

When you look at the graph of the results of an experiment, you are looking at the relationship between the two variables.

Usually, the independent variable (IV) is on the x-axis and the dependent variable (DV) is on the y-axis.

The graph shows how the independent variable affects the dependent variable, or makes it change.

D.R.Y. M.I.X.

D = dependent variable

R = responding variable

Y = Y-axis

M = manipulated variable

I = independent variable

X = X-axis

Let's talk about a good hypothesis (again)!

A good hypothesis shows how the INDEPENDENT VARIABLE affects the DEPENDENT VARIABLE.

HYPOTHESIS = Testable Idea/Explanation

If...I change this(IV), then...this will happen(DV)

(DV) depends on (IV)

(IV) affects (DV)

A hypothesis is more than just a guess! It is a proposed explanation for a set of observations that can be tested!

But how can I tell if my Independent Variable is making a difference? By having a control group!!! Here's an example of an experiment with a control group

Hmm...I wonder if a plant will grow taller if it gets fertilizer.

HYPOTHESIS: If the plant gets fertilizer, it will grow taller.

PLANT A

Gets 100 ml of water per day, plus fertilizer

PLANT B

Gets 100 ml of water per day, without fertilizer.

The CONTROL GROUP allows you to compare the results at the end of the experiment to see if the independent variable affected the dependent variable.

In the example above the control (the plant the red arrow points to) does not have the independent variable applied to it. (In this case fertilizer.)

The other groups in the experiment are called TEST GROUPS because the IV is tested on them.

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