Minersville Area School District 7th Grade Life Science: Chapter 1 Mr. Motuk

1. CHAPTER 1
EXPLORING AND
CLASSIFYING LIFE

2. Chapter 1: Section 1
WhatisScience?

3. SECTION 1- What is Science?
A. SCIENCE – An organized way of studying things
and answering questions.
B. Some types of science:
• 1) PHYSICS – The study of energy, matter and
motion.
• 2) CHEMISTRY – Study of elements and how they
behave
• 3) EARTH SCIENCE – Study of the universe and how
it all works.

4. • 4. LIFE SCIENCE – The study of
living things (organisms)
• Types of Life Science:
a. ZOOLOGY – Study of
animals
b. BOTANY – study of plants
c. ECOLOGY – Study of
organisms and their
relationship with the
environment.
d. GENETICS- Study of how
traits are passed between
generations.

5. • SCIENTIFIC METHOD – Series of steps used to try
and solve problems.
• STEPS:
• 1. State a PROBLEM – Something that needs to be
solved.
• 2. Gather Information – DATA
• 3. Form a HYPOTHESIS – Prediction or educated
guess
• 4. Test the hypothesis – EXPERIMENT
• Parts of an experiment:
• CONTROL – Something that stays the same
• VARIABLE – something that changes
• Each Experiment should have only 1
VARIABLE.

6. • 5. Analyze results
• 6. Draw CONCLUSIONS – A logical answer to the
problem.
• THEORY – Explanation of things based on many
observations/ experiments.
• EX: Theory of Evolution, Theory of relativity
• LAW – Statements that explains how things
work in nature. They seem to be true all the
time.
• EX: Law of Gravity, Newton’s Laws of Motion

7. NEWTON’S LAW OF
GRAVITY

8. • Scientists got together in the 1970’s and
came up with a universal system of
measurement that every country in the
world would use.
• That system was called the
INTERNATIONAL SYSTEM OF UNITS (SI).
• This system is based on the #10
• All countries are currently using this
system except the USA.
• This system uses several terms that we
need to learn.

9. • MASS – SI Measure of the amount of matter in
an object. Doesn’t change much daily.
• SI uses GRAMS to measure mass
• WEIGHT – The measure of the amount of gravity
holding an object down. Changes daily or
depending on your location on earth. The closer
to the earth’s core you are the more you will
weigh.
• We use pounds to measure weight.
• VOLUME – The amount of space occupied by an
object.
• SI uses LITERS
• LENGTH – A measure of distance
• SI uses METERS

10. USING SI
• SI uses 3 main units: Liters, Meters and Grams.
• Prefixes are also used to help convert between
units.
• THE PREFIXES IN SI
• Prefix Abbreviation Multiplier
• Kilo k 1000
• Hecto h 100
• Deka da 10
• Base unit (Meter, Liter, Gram) (m,l,g) 1
• Deci d .1
• Centi c .01
• Milli m .001

11. • How to convert in the SI system
• K-H-D-Base Unit-d-c-m
• Whenever you go from large to
small, you move the decimal
that many places to the right.
• When you go from small to large,
you move the decimal that many
places to the left.
King-Henry-Died –By-drinking-
chocolate-milk

12. Converting
Temperatures
• The US is the only country to
use the temperature scale
Fahrenheit. (F)
• All other countries use Celsius
(C) to measure temperature.
• You need to be able to convert
in between the 2 scales if you
will ever travel outside the US

13. • Anytime you start with a Fahrenheit
temperature and you want to change
it into Celsius use the following:
F – 32
1.8
• So lets do an example: Say it is 56oF and you
want to change it into C.
• First you take 56 – 32 and get 24.
• Then you take the 24 and divide it by 1.8
• Your answer in Celsius is 13.3o

14. • Now let’s go the other way from
Celsius into Fahrenheit
(C x 1.8) + 32
• Let’s say you are going on vacation to
Haiti and the temperature there is
46oC, what is that equal to in
Fahrenheit.
• First you take 46 x 1.8 and get 82.8
• Next you take the 82.8 and + 32 =
114.8 oF.
• HOT HOT HOT!!!

15. CHAPTER 1: SECTION 2
LIVING THINGS

16. • SECTION 2- LIVING THINGS
• ORGANISM – Any living thing
• What does it mean to be alive??
• CHARACTERISTICS OF LIFE
• 1) Organisms must show some level of
organization, here are the levels:
• A) CELL – Basic unit of life
• B) TISSUE – Cells working together to do a
certain job. Ex: Heart tissue, brain tissue,
bone tissue, etc.
• C) ORGANS – Tissue working together to do a
certain job. EX: Heart, Kidney, Brain, etc.
• D) SYSTEM – Organs working together to do a
certain job.
• There are 10 human body systems
• E) ORGANISM – A complete living thing

17. • HUMAN BODY SYSTEMS
• 1. RESPIRATORY – help breathing EX: Lungs,
windpipe, nose
• 2. SKELETAL – support EX: Femur, Skull, Ribs
• 3. INTEGUMENTARY – protection EX: Skin,
Fingernails, Hair
• 4) DIGESTIVE – helps break down food and get
rid of solid waste.
– EX: Stomach, Large Intestine, Mouth
• 5) MUSCULAR – controls all movement
• EX: Biceps, Triceps, Tongue
• 6) EXCRETORY – gets rid of liquid waste EX:
Kidneys, Bladder
• 7) REPRODUCTIVE – Make babies EX: Testes,
Ovaries
• 8) NERVOUS – Controls feeling EX: Brain, Spinal
Cord

18. • 9) ENDOCRINE – Controls all hormones and
chemicals EX: Thyroid, Pituitary,
Ovaries
• 10) CARDIOVASCULAR (CIRCULATORY) –
Moves blood EX: Heart, Veins,
Capillaries, Arteries
• 2) Must respond to changes in environment.
• A) STIMULUS – Something an organism
responds to.
• Ex: Weather getting colder
• B) RESPONSE – The reaction of an organism to
a stimulus.
• EX: Hummingbirds flying south for the
winter
• C) HOMEOSTASTIS – The regulation of an
organism’s inside despite outside changes
• EX: Sweating when hot, Fever when sick, etc.

19. • D) ADAPTATION – Characteristic an organism has
which makes it better able to survive in it’s
surroundings.
• EX: Tree’s losing leaves in fall, Dog’s shedding
fur, Robins migrating for the winter, etc.
• 3) Must use ENERGY – Ability to do work.
• Most energy comes either directly or indirectly
from the SUN
• 4) Must Grow and Develop
• GROWTH – to increase in size
• DEVELOPMENT – to change form in becoming
an adult.
• EX: Caterpillar to a butterfly, tadpole to a
frog

20. • LIFE SPAN – The length of time
an organism is expected to live.
• EX: Humans - 80 years
• Mayfly 1 day
• 5) REPRODUCTION – The ability
to make similar offspring to the
parents.
• 6) A Place to live – when the
environment becomes to
crowded the competition for
space costs lives.
• 7) Raw Materials – Every
organism needs water, oxygen,
food
• Most organisms are at least 50
% water.
• You are made up of 70 %.

21. CHAPTER 1: SECTION 3
WHERE DOES LIFE COME
FROM

22. SECTION 3 – Where does life come from?
• SPONTANEOUS GENERATION – The theory that
living things could come from nonliving things.
• EX: Rained worms, meat made maggots
• Scientists of course did not believe in this and
had to prove it wrong.
• 1668 – Francesco Redi- tested the maggots and
meat belief. Here is his experiment:
• 1) Took 2 identical raw pieces of meat and put
them into 2 identical jars.
• Covered one of them with a piece of light cloth
(so the air could get through).
• Waited
• Upon his return he found that the uncovered jar
had maggots on the meat, but the covered jar did
not.
• Since both jars did not have maggots, he stated
that SG had to be wrong.

23. REDI’S EXPERIMENT

24. • LOUIS PASTEUR – tested broth (meat juice).
• 1) He boiled the broth to make it free of all
germs (sterile).
• 2) Then he place it into an s-shaped flask.
These flasks allowed the air to enter the
broth not the dust. All the dust gets caught
in the curve of the s.
• 3) When he returned he found no
contamination to any of the flasks.
• 4) For fun he then tilted the flasks so the
dust could enter the broth, within days the
broth was contaminated.
• He concluded that since the first test
showed no contamination, broth doesn’t
make germs but air carries them.

26. • Where did life come from?
• Earth is believed to be 4.6 billion years
old.
• The oldest found life is about 3.3 billion
years old.
• ALEX OPARIN – suggests that the Earth’s
early atmosphere had no oxygen in it but
had ammonia, hydrogen, methane and
water vapor.
• He believes that these gases combined to
form the simplest of life (Bacteria) and
then the cycle began.

27. CHAPTER 1: SECTION 4
How Are Living Things
Classified?

28. Section 4 – How are living things classified?
• Hundreds of new organisms are discovered
and named each year.
• Most of these new critters are plants or
insects.
• Most are found in the tropical rain forest.
• CLASSIFY – to group things based on
similarities.
• EX: Grocery Stores are grouped by the type
of food.
• Libraries are grouped by the type of book
• Record Stores are grouped by the CD, tape
and then by the type of music.

29. • ARISTOTLE – was the first person ever to
classify living things.
• He developed a science of classifying and
naming organisms called TAXONOMY.
• He divided all living things into 2 large
groups which he called KINGDOMS.
• Those 2 groups were called PLANTS and
ANIMALS.
• He used 2 main characteristics to figure out
which kingdom the organism should be
placed.
• Those 2 traits were color and movement.
• If it was green and didn’t move it was a
plant
• If it wasn’t green and moved it was an
animal.

30. • Inside the Plant Kingdom there
were 3 subgroups. (SIZE)
• 1)The Small plants- HERBS
• 2)The medium plants – SHRUBS
• 3)The large plants – TREES
• Inside the Animal kingdom there
were 3 subgroups. (HABITAT)
• 1)The air animals – AVIAN
• 2)The water animals – AQUATIC
• 3)The land animals -
TERRESTRIAL

32. ANIMAL GROUPS

33. • Kingdom is the largest of all the
taxonomic categories.
• There were many problems with
Aristotle’s system.
• EX: Frogs – they are green and
moved.
• Red Maple Trees- red and don’t move
• Ducks- fly through the air, float in
water and nest on land.
• So improvements had to be made.

34. • CAROLUS LINNAEUS – created a better system to
classify organisms.
• His system was based on similarities in body
structures and systems, size, shape, color and the
method of obtaining food.
• He also created a system for naming organisms.
• BINOMIAL NOMENCLATURE – the 2 word naming
system used to name all organisms.
• This is also called the Scientific Name
The first word is called the GENUS
• The second word is called the SPECIES

35. • When organisms are named there are several
rules that must be followed:
• 1) The Genus always comes first, is
capitalized and either italicized or
underlined.
• 2) The Species always is second, is lowercase
and either italicized or underlined.
• Only organisms of the same species can
successfully reproduce without any
problems.
• EX: Horse + Donkey = Mule
• Ligers
• Zedonk

39. • Some examples of the scientific name in use
are:
• Canis familiaris – Dog
• Felis domesticus – Cat
• Homo sapiens – Humans
• Canis lupus – Wolf
• Since dogs and wolves share the same genus
name they are cousins. But they still do not
share species names, there is difficulty
interbreeding them
• All the different breeds of dogs are all Canis
familiaris. So they can interbreed – MUTT.

40. • These are always written in LATIN – because
when this system was created all educated folk
WORLDWIDE spoke Latin.
• PHYLOGENY – An organism’s evolutionary history
• TODAYS CLASSIFICATION SYSTEM:
• Based on several things:
• Presence of a nucleus
• How many cells are present
• Ability to make food
• Ability to move
• DNA
• Body structure
• Phylogeny

41. • The current classification has
been expanded to 6 kingdoms.
• Lets discuss the kingdoms in
order from simplest to most
advanced.
• 1) ARCHAEBACTERIA – one
celled bacteria that live in
extreme environments. EX: Salt
water, volcanoes, sulfur springs
• Prokaryotes
• Some make own food some do
not

42. • 2) EUBACTERIA – 1 celled bacteria that live in
normal environments, prokaryotes
• EX: streptococcus, cyanobacteria (green), E. Coli
• 3) PROTISTA – 1 or many cells, most live in water.
Eukaryotes EX: Paramecium, Amoeba, Euglena

43. • 4) Fungi – Have 1 or many cells.
Eukaryotes EX: Mushrooms, molds, and
yeasts
• 5)Plants – many cells Eukaryotes EX:
roses, grass, apple tree, moss

44. • 6) Animal – many celled and most advanced
kingdom EX: Humans, monkeys, sponges
• DO THE CHART ON THE BOARD!!!!!

45. • PROKARYOTE – Organisms without a true nucleus.
The nuclear material (DNA) is there but the
membrane around it is missing.
• EX: Archaebacteria, Eubacteria
• EUKARYOTE – Organisms with a true nucleus. Have a
membrane plus all nuclear material.
• EX: Animals, protists, fungus, plants

47. Ways organisms get food
• 1) Producers – Can make their own food by
photosynthesis
• EX: Plants, green bacteria, green protists
• 2) Consumers – Can not make their own food
so they must go and get it somehow.
• 3 TYPES OF CONSUMERS:
• 1) PARASITE – Feed off of another living thing.
Usually just harms the host.
• EX: Fleas, Ticks, Leech

48. • 2) DECOMPOSER
(SAPROPHYTE) – Feed off
of already dead things
• EX: Humans, Flies, Crows,
Turkey Vultures
• 3) PREDATOR – Hunts,
kills and eats it’s prey
immediately
• EX: Tigers, Grizzly Bears,
Eagles, Red Tailed Hawks

49. • THE TAXONOMIC GROUPS
• From biggest to smallest
•KINGDOM
•PHYLUM
•CLASS
• ORDER
• FAMILY
• GENUS
• SPECIES

50. • 1.5 million species have been identified so far.
• Scientists believe there are between 5-30 million total
species on Earth.
• SUMMARY OF CLASSIFICATION
• 1) Aristotle started out with 2 – plant and animal
• 2)Then when the microscope was created a third
kingdom, the protist evolved.
• 3) The # went to 5 – animals, plants, fungi, protist and
bacteria (Moneran)
• 4) Now there are 6 – animals, plants, fungi, protists,
eubacteria, and archaebacteria.
• In the future a 7th??? - Viral

51. • Species Diversity – Great Variety of plants, animals
and other species living in an area.
• The more diverse an area is, the more stable it is.
• In 1 hectare (50 acres) of rain forest there are
around 200 species of plants and 1000 species of
animals.
• So this is a region of excellent species diversity.
• Unfortunately every minute there are about 1000
acres of rain forest cut down by humans.

53. • Extinction – When a species
no longer exists.
• Examples of extinct species:
Dodo bird, passenger pigeon,
Carolina Parakeet,
Tasmanian Wolf, Dinosaurs

54. • Endangered – Animals
that are close to becoming
extinct.
• EX: Florida Panther, Bog
Turtle, Gray Wolf, Manatee

55. • IDENTIFYING ORGANISMS
• Common names – scientists do not use common
names because they can be very confusing. Often
there are to many names for the same organism.
• EX: Groundhog and woodchuck
• Puma, Cougar and Mtn. Lion all the same.
• Instead scientists only use scientific names

56. • Other tools that help identify
organisms
• Field Guide – A book of traits and
pictures to identify organisms.
• Dichotomous Keys – A detailed
list of traits used to classify
organisms