Properties of Life

What characteristics do living creatures have in common?

carbohydrates proteins

Living creatures are ORGANIZED All made of the same collection of

chemicals, but we are organized as… molecules

proteins, fats, carbohydrates, nucleic acids

DNA

Living creatures are ORGANIZED All made of the same collection of

chemicals, but we are organized as… organelles & cells

plant cells & animal cells

animal cell

plant cell

Living creatures are ORGANIZED All made of the same collection of

chemicals, but we are organized as… organs & organ systems

respiratory, circulatory, digestive, etc.

Living creatures RESPOND Respond to internal changes

Homeostasis maintaining balanced conditions inside the

body

Respond to external changes

Living creatures use ENERGY

mitochondria

Metabolism all the reactions your body performs to

make & use energy eating & digestion & elimination of waste synthesis = building cellular respiration = making energy

Living creatures GROW & DEVELOP Change over an individual’s life time

get bigger mature

so they can reproduce

Living creatures REPRODUCE Make the next generation

Scientific Method…

…It’s how we think about the world around us…

Scientific Method is…An organized approach to asking

questions and making discoveries.The way that scientists (and many non-

scientists) think about problems that they encounter.

Scientific Method:

Observation Problem Hypothesis Experiment Data Conclusion Theory

Observations:

Information gathered using the five senses oror tools

Problem:

A question one might ask based on the observations that are made.

Hypothesis

A possible explanation of the problem that we wish to test. (it doesn’t have to be correct!!)

Many hypotheses can be made – they predict the outcome of an experiment.

hypothesis.gif

Experiment

This video shows an impact experiment of a high-speed impact into a frozen comet-like material (dust, ice, window cleaner and Worchestershire sauce) over a highly porous target (garden perlite). The impact makes a small hole in the comet, simulating a strength-controlled crater, but a large crater grows below and peals back the surface crust like petals of a flower. The result is similar to a deeply buried explosion.

Credit: NASA

An organized test of a hypothesis.

Data

The results of experiments. Data can be expressed as numbers or descriptions.

Example: the elephant is 3 meters tall.

Conclusion

What has been learned from the experiment.

Conclusions are supported by data.

Theory

A broad explanation of natural events that is strongly supported by a body of evidence - time tested by many people.

Example: The theory of gravity

Some other scientific method terms…

Inference – a possible explanation based on an observation.

Opinion – What someone thinks about something. We try to keep this out of science!

Some other scientific method terms…

Control – What we compare our data against. (usually helps to show what we already know)

Some other scientific method terms…Variable – that which is

manipulated in an experiment to get a result.

Some other scientific method terms… Independent Variable – When this

changes, it results in change in the other variable.

Dependent Variable - That which changes as a result of a change in the ind. Variable.

Validity:A good experiment should….Be easily repeatable.Have a large sample size Control

for as many variables as possible.

Graphing Your Data

Showing patterns & trends

A picture is worth a

thousand words!

Types of data (information) Variables

what you measure in an experiment dependent variable

measured variable unpredictable change: we don’t know how it

will change until we do the experiment Y-axis

independent variable manipulated variable predictable change: it only

changes because we chose how it would change

X-axis

The effect of _____________

on _____________

INDEPENDENT

DEPENDENT

Examples of experiments 1 How does fertilizer affect the growth rate

of plants? we set up an experiment testing different

amounts of fertilizer on different plants & measuring the growth (height) of the plants: dependent variable (Y-axis)?

height of plants

independent variable (X-axis)? amount of fertilizer

The effect of _____________

on _____________

Amount of Fertilizer

Height of Plants

Examples of experiments 2 How does exercise affect heart rate of

10th grade student? we set up an experiment testing

different lengths of time of exercise (minutes) on the heart rate of students: dependent variable (Y-axis)?

heart rate

independent variable (X-axis)? minutes of exercise

The effect of _____________

on _____________

Exercise

Heart Rate

Examples of experiments 3 What’s the favorite drink of students?

we set up an experiment surveying students and asking which is their favorite drink : dependent variable (Y-axis)?

number of students

independent variable (X-axis)? type of drink

The effect of _____________

on _____________

Type of Drink

How many students chose it

Making pictures out of data Graphs

line graphs graphing data that shows continuous change

bar graphs (or histograms) graphing data that is in disconnected groups

How’s a critterto choose?

How does elevation affect temperature?

elevation

tem

pe

ratu

re

5

10

15

20

25

30

0 500 1000 1500 2000 25000

elevation (feet above sea level)

temp.

(°C)

0 30

500 25

1000 20

1500 15

2000 10

2500 5

1200 ft?

18

Line graph!

1200

Which drink do you like best?

type of drink

nu

mb

er

of

stu

den

ts

1

2

3

4

5

6

Coke Pepsi water tea Gatorade0

drink number

Coke 1

Pepsi 1

Water 4

Iced tea 4

Gatorade 3

Bar graph!

• name and date• Title: Descriptive title explaining the purpose of the experiment. • Purpose: The question being answered in the experiment.

Lab Report Template

• Hypothesis: What you believe will happen, in the form of an “If, then” statement.

Lab Report Template

•Materials: List all materials used in the lab•Procedure: List step by step how to complete the lab•Data: Independent and Dependent variable listed

Lab Report Template

•Analysis: At least a paragraph that explains what your data shows•Conclusion: Ties lab together. Is hypothesis supported or refuted? Include any suggestions for improving the experiment. What could have been a source of error and give a suggestion for further research.

Lab Report Template