Transcript Chapter 2: It*s Alive!! Or Is It?

CHAPTER 2: IT’S ALIVE!! OR IS
IT?
7th Grade Life Science
STANDARDS
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7.1 a Students know cells function (to work)
similarly ( in almost the same way) in all living
organisms.
7.2 a Students know the differences between life
cycles (a repeating series of changes) and
reproduction methods of sexual and asexual
organisms.
SPIDER MAP
For chemical
processes
Through cell division
In life stages
Structural unit
Grow and
Develop
Use energy
Functional unit
cells
DNA
Controls
heredity
sexually
asexually
Sense and
Respond to
change Internally
Reproduce
(homestasis)
externally
SECTION 1
CHARACTERISTICS OF LIVING THINGS
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Key Concept: Living things have six characteristics in common.
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Vocabulary
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Cell: the smallest functional and structural unit in all living organisms
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Homeostasis: the maintenance of a constant internal state in a changing
environment
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Sexual reproduction: reproduction in which the sex cells from two parents
unite to produce offspring that share traits from both parents
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Asexual reproduction: reproduction that does not involve the union of sex
cells and in which one parent produces offspring that are genetically
identical to the parent
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Metabolism: the sum of all chemical processes that occur in an organism
LIVING THINGS HAVE CELLS
 All
living things are composed of
_______________ cells
 All cells are surrounded by a
_______________
 In one celled organisms, different
parts of the cell perform different
functions.
 In organisms made up of _______
cells, specialized cells perform
specialized functions
LIVING THINGS SENSE AND RESPOND TO
CHANGE
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A change that affects the activity of an organism
is called a stimulus (stimuli – plural)
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Can be chemicals, gravity, light, sounds, hunger, or
anything that causes a response in the plant
Homeostasis
Conditions on the inside of an organism must stay
the __________ no matter what goes on outside
 An organism must maintain stable internal
conditions to _________________.
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LIVING THINGS SENSE AND RESPOND TO
CHANGE
Responding
 The
to External Changes
body will sweat when ________
or shiver when ________ to
maintain homeostasis.
 Some organisms will move from
one environment to ____________
to maintain their body
temperature.
LIVING THINGS REPRODUCE
Living
things make offspring
like themselves by either
_______________ reproduction or
____________________
reproduction.
LIVING THINGS HAVE DNA
 DNA
– Deoxyribonucleic Acid
 Carries the instructions for the
organism’s __________
 When organisms reproduce, they
pass copies of their ______ to their
offspring.
 The passing of the traits is known as
_________
LIVING THINGS USE ENERGY
 Use
energy to carry out chemical activities
 Examples
Changing energy into ________
 Breaking ________ food
 Moving material ______ and ______ of cells
 Growing
 ______________ cells
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 Metabolism:
sum of all activities
performed by the _________________
LIVING THINGS GROW AND DEVELOP
 All
living things __________ during
parts of their lives
 Single celled organisms get
__________ and divide.
 Multicellular organisms
The number of cells _____________
 The organism gets _______________
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SUMMARY OF SECTION 1
 Organisms
are made up of ______ or
_______ cells.
 Organisms _________ and __________ to
stimuli.
 Organisms reproduce through ___________
or ___________ reproduction.
 Organisms have __________.
 Organisms use __________ to carry out
their activities.
 Organisms ________ and ____________.
SECTION 2
THE NECESSITIES OF LIFE
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Key Concept: Every living thing needs water, a place
to live, and food in order to survive.
Vocabulary
Producer: an organism the can make its own food by using
energy from its surroundings
 Consumer: an organism that eats other organisms or
organic matter
 Decomposer: an organism that gets energy by breaking
down the remains of dead organisms or animal wastes and
consuming or absorbing the nutrients
 Protein: a molecule that is made up of amino acids and
that is needed to build and repair body structures and to
regulate processes in the body.
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VOCABULARY
Carbohydrate: a class of molecules that includes
sugars, starches, and fiber
 Lipid: a fat molecule or a molecule that has
similar properties
 Phospholipid: a lipid that contains phosphorus
and that is a structural component in cell
membranes
 ATP: adenosine triphosphate, a molecule that
acts as the main energy source for cell processes
 Nucleic Acid: a molecule made up o subunits
called nucleotides
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FOUR NECESSITIES OF LIFE
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WATER
Makes up 70% of your cells and the cells of almost all
living things
 Most chemical reactions require ______________
 Organisms differ in how much water they need and
how they get it
 People can survive ____ days without water

Why do cells require water?
_______________________________________________
_______________________________________________
_______________________________________________
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FOUR NECESSITIES OF LIFE
 AIR
Mixture of several gases including
_____________, _______________, and
____________ ______________
 Some organisms use oxygen from the ______ or
may be dissolved in _____________.
 Some organisms use oxygen and carbon
dioxide to produce ___________ and oxygen in
the process of photosynthesis
 Some organisms do not need air
 Anaerobic organisms are those that can live
without __________
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FOUR NECESSITIES OF LIFE
A
PLACE TO LIVE
 All
living things need a place to
live that has all of the things that
they need to ______________
 Space on Earth is _____________.
 Organisms must ______________
for food, water, and other
necessities.
FOUR NECESSITIES OF LIFE
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FOOD
Food gives _____________
 Not all organisms get food in the same way. They
can be grouped into three categories.
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Producer
Consumer
Decomposer
• Plants
• Make their
own food
• Use
photosynthesi
s to produce
food and
oxygen
• Eat other
• Break down
organisms
nutrients from
• Rely on others
dead
for food and
organisms or
oxygen
animal waste
• Must eat their
food
PUTTING IT ALL TOGETHER
Some living things ________ their own food.
 Some get food from _____________ other
organisms.
 All organisms must break down their food to use
the ______________ in it.
 Nutrients are made up of molecules ( a substance
made when two or more atoms join together)
 Molecules of different kinds of atoms are
compounds.
 Molecules found in living things are ___________,
___________, ____________, _____________,
_____________ and ____________.
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PROTEINS
Almost all live processes involve ___________
 Proteins are made up of smaller molecules called
__________ _____________.
 Some proteins are made up of only a few amino
acids while others are made up of thousands
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Proteins in Action
______________ have many functions
 Some proteins help other cells do their jobs like hemoglobin
in the red blood cells.
 They can ______________ cells
 Enzymes start up or speed up chemical reactions in
________.
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What function do enzymes in cells serve?
CARBOHYDRATES
 Molecules
made of ______________
 Provide and store ___________ for the
cells.
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Simple Carbohydrates
One or a few sugar molecules
 Table sugar and the sugar in fruits are examples
 Glucose is the most common source of energy for cells
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Complex Carbohydrates
When an organism has more sugar than it needs it
makes ______________ carbohydrates
 Made up of hundreds of sugar molecules
 Potatoes store extra sugar as STARCH
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LIPIDS
Molecules that cannot mix with water
 Some store energy and others form the membranes
of the cells
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Phospholipids
All cells are surrounded by a cell membrane
 __________________ are the molecules that form much of the
cell membrane
 Head is attracted to water, the tail is not
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List two functions of cell membranes.
__________________ and ________________________
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Fats and Oils
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Lipids that store _________________
Most lipids stored in plants are ____________ and animals are
____________
ATP
 Adenosine
triphosphate
 Major ________ carrying molecule of
cells
 Energy in carbohydrates and lipids
is transferred to __________ to
provide fuel for cellular activities
NUCLEIC ACIDS
Carry the directions for how to make ___________
 Made up of smaller molecules called ____________

There could be thousands
 Sequence stores information

DNA is a nucleic acid
 Like a cookbook called How to Make Proteins

Cells get directions from the ______________ of the
nucleotides in DNA
 Tells the cell the order in which amino acids are
___________ together to make the protein.
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SUMMARY
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The cells of living things need __________ to function.
The cells of some living things need gases, such as
oxygen, to release the energy contained in ______.
Living things must have a ________ to live.
Cells store energy in carbohydrates, which are made
up of ____________.
Proteins are made up of ___________________. Some
proteins are enzymes.
Lipids store energy and make up ______ membranes.
Cells use molecules of ______ to fuel their activities.
Nucleic Acids, such as _______, are made up of
nucleotides.