Download Living Things Reproduce

Characteristics of Living Things
Chapter 2: It’s Alive Or Is It?
Ga. Std.: S7L2: Students will describe the structure and function of cells.
Ga. Std.: S7L3(b) – compare and contrast sexual and asexual reproduction.
Most organisms must eat other organisms in order to obtain energy for survival or make
their own food (plants and photosynthesis), but we have also found some organisms that
obtain their energy from hydrogen sulfide. These organisms are bacteria. Other
organisms then feed on the bacteria. These bacteria are found in deep ocean trenches.
Chapter 2: Section 1
Every living thing has cells. Humans are composed of about 80 trillion cells. A cell is a
membrane-covered structure that contains all of the materials necessary for life.
Most cells are too small to be seen with the naked eye. Organisms with many cells have
cells that carry out special functions. Example: Your nerve cells carry impulses to your
brain. These impulses may be signals to walk, laugh, talk or be silent.
All organisms have the ability to sense change in their environment and respond to that
change. (Getting more cloths if you are cold, taking a sweater off if you are hot).
Living organisms respond to change.
A change in the organism’s environment that affects the activity of the organism is called
a stimulus. (Plural - stimuli).
Stimuli can be chemicals, gravity, darkness, pain, light, sounds, tastes, or anything that
causes an organism to respond.
Homeostasis
The maintenance of a stable internal environment is called homeostasis.
Even though an organism’s external environment changes, their internal environment
must remain fairly constant. Example: the human body must remain at 37o Celsius. If it
falls below this, we could go into hypothermia (hypo – below, thermia – temperature)
or if it rises much above we could go into hyperthermia (hyper – above, thermia –
temperature). Both of these conditions may result in death.
**The maintenance of a stable internal environment is called homeostasis.
If you are too hot, your body sweats. This is your body’s method to cool itself off and
maintain homeostasis. If you are cold, your body shivers. This creates heat from the
muscles and raises your body temperature to maintain homeostasis.
Living Things Reproduce
Organisms make other organisms like themselves. They can do this in one of two ways:
asexual reproduction, or sexual reproduction.
In asexual reproduction a parent produces offspring that are identical to the parent.
(Hydra producing buds on page 38).
In sexual reproduction, it requires two organisms to serve as parents to produce
offspring, which will have traits from both parents. (Bears).
Can you think of other asexual and sexual organisms?
Living Things Have DNA
The cells of all living things contain a special molecule called DNA (deoxyribonucleic
acid). DNA provides the instructions to build the proper proteins in the organism. These
proteins take part in the organism’s cells activities.
The transmission of the characteristics from one generation to the next is called heredity.
What are some traits you received due to heredity?
Living Things Use Energy
All living organisms must have energy in order to carry out daily activities. An
organism’s metabolism is the total of all of the chemical activities that it performs.The
cells in your body must transport materials into and out of them in order to remain alive.
All of this requires energy and the total energy needs is your metabolism.
Living Things Grow and Develop
All living things, whether they are made up of one cell or many cells, grow during
periods of their lives. (Single celled organisms have their cell get larger. Multi-cellular
organisms add cells to become larger.)
Organisms also go through different stages of development. Humans go through
different stages as we develop. (Embryo, fetus, baby, child, adolescent, young adult,
middle aged, senior citizen.) (An oak tree begins as an acorn, seedling, sapling, and then
a tree).
Review
1.
What characteristics of living things does a river have? Is a river alive?
A river has energy (it moves – kinetic energy), and can grow larger
(flooding). But it is not alive because it is not made of cells, cannot
respond to stimuli, has no DNA, and cannot reproduce.
2.
What does a fur coat on a bear have to do with homeostasis?
Homeostasis is the maintenance of a stable internal environment. The fur
coat of a bear helps it keep a stable body temperature.
3.
How is reproduction related to heredity?
Heredity is the passing of characteristics from parents to offspring. When
organisms reproduce, offspring inherit copies of their parents DNA.
4.
What are some of the stimuli that you respond to in your environment?
Characteristics of Life
Chapter 2 Section 2 Notes
GPS: S7L4
The Simple Bare Necessities of Life
Food
All living things need food. They must produce their own or capture and consume other
organisms.
Making Food
Some organisms such as plants are called producers because they can produce their own
food. Like plants, most producers use the energy from the sun to produce their food by
photosynthesis. The bacteria in deep sea trenches that use hydrogen sulfide are carrying
our chemosynthesis to produce their food (producing food from chemicals).
Getting Food
Organisms that get their food by feeding on other organisms are called consumers.
Some consumers are decomposers. These organisms get their food by breaking down the
nutrients in dead organisms or animal wastes. Fungi are decomposers (mushrooms).
Water
The cells of all organisms are made up of approximately 70% water. We can only live
without water for about 3 days. We can live without food for over a week. Most of the
metabolism processes must have water in order to function properly. Some organisms get
all of their water in the food they consume (kangaroo rat).
Air
Air is a mixture of gases, mainly nitrogen, oxygen and some carbon dioxide. Animals
must take in air and use the oxygen for respiration in order to survive. Plants take in
carbon dioxide and carry out photosynthesis and release oxygen a by-product.
A Place to Live
All organisms must have somewhere to live that contains all the things they need to
survive. Some organisms require a large amount of space (elephants, wolves). Some need
very little space (bacteria).Space is limited so organisms compete for space, food, water,
air and other necessities. Many organisms become territorial and defend their space and
resources.
Review
1.
Why are decomposers categorized as consumers? How do they differ from
producers?
Because they must obtain the food they need from other organisms. Decomposers
cannot make their own food like producers are able to do.
2. Why are most cells 70% water?
Most of the chemical reactions that occur in cells depend on the presence of
water.
3. Could life on Earth as we know it exist if air contained only oxygen?
No! Green plants, algae and some bacteria need carbon dioxide gas as well as
oxygen. Without the carbon dioxide, they could not survive and other organisms
could not rely on them as a food source.
4. How might a cave, an ant, and a lake meet the needs of an organism to survive?
The cave could serve as a place to live, the ant could be food and the lake
could provide water.
Characteristics of Life
Chapter 2 Section 3 The Chemistry of Life
All living things are made of cells, but what are cells and non-living things made of?
They are made of tiny building blocks known as atoms.
Atoms are made up of sub-atomic units, the proton, neutron and electron.
A substance made of only one type of atom is called an element. When two or more
atoms join together, they form a molecule.
The molecules found in living things are usually made of different combinations of six
elements: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. These elements
combine to form proteins, carbohydrates, lipids, nucleic acids, and ATP (adenosine
triphosphate). Remember the elemental symbols for carbon (C), hydrogen (H), nitrogen
(N), oxygen (O), phosphorus (P), and sulfur (S).
Proteins
Proteins are large molecules made up of amino acids. Organisms break down
proteins in food they eat to provide their cells with amino acids. These amino acids are
then linked together to form new proteins based on the cells needs.
Proteins in Action
Proteins have many different functions. Example: hemoglobin is the protein that
allows for the transportation of oxygen from our lungs to our cells. Some proteins are
called enzymes and these help speed up chemical reactions in an organism’s body.
Carbohydrates
These are a group of compounds made from sugars. Cells use carbohydrates as a
source for energy storage.
Types of Carbohydrates
Simple carbohydrates (simple sugars) are made of one sugar molecule or a few linked
together. (Table sugar, natural sugars from fruits).
Complex carbohydrates are made of hundreds of sugar molecules linked together. (Plants
make a complex carbohydrate called starch). (Potato)
Lipids
These are compounds that cannot mix with water. These also store energy and
form membranes of cells.
Fats and Oils
These are lipids that store energy. At room temperature, fats are solid and oils are
liquid. Most lipids in plants are oils and most lipids in animals are fats.
Phospholipids
A membrane surrounds all cells. This membrane is composed of a double
phospholipid layer. The head of the phospholipid is hydrophilic and the tail is
hydrophobic. (See figure 13 in text).
Nucleic Acids
Nucleic acids are composed of subunits called nucleotides. These subunits include
a nitrogenous base, a phosphorus, and a sugar. Nucleic acids are sometimes referred to as
the blueprints of life because they contain all of the information for cells to make the
proteins they need. DNA (deoxyribonucleic acid) is a nucleic acid and contains all of the
information to make the proteins that cells need.
The Cells Fuel
All cells need fuel and this fuel is in the form of ATP (adenosine triphosphate).
ATP is the major fuel for all cells that require energy.
REVIEW
What are the subunits of proteins? Of starch? Of DNA?
The subunits for proteins are amino acids. For starch, the subunits are complex
carbohydrates or hundreds of sugars linked together. For DNA, the subunits are
nucleotides.
What do carbohydrates, fats, and oils have in common?
They all store energy.
Are all proteins enzymes?
No. Not all proteins are enzymes. Enzymes are special proteins that speed up certain
chemical reactions in the cell.
What would happen to the ATP in your body if you did not eat enough carbohydrates?
How would this affect your cells?
The supply of ATP would decrease. The cells would still need ATP for energy, so they
ATP would be obtained from other sources like lipids.
Characteristics of Life
Chapter 2: Section 1 Reading Worksheet
GPS: S7L2
Ac
is a membrane-covered structure that contains all of the materials
necessary for life.
A change in the organism’s environment that affects the activity of the organism is called
a
s
.
The maintenance of a stable internal environment is called h
.
Organisms make other organisms like themselves. They can do this in one of two ways: a
reproduction, or
s
reproduction.
In a
parent.
reproduction a parent produces offspring that are identical to the
In s
reproduction, it requires two organisms to serve as parents to produce
offspring, which will have traits from both parents.
The cells of all living things contain a special molecule called D
.
The transmission of the characteristics from one generation to the next is called h
.
All living organisms must have energy in order to carry out daily activities. An
organism’s
m
is the total of all of the chemical activities that it performs.
All living things whether they are made up of one cell or many cells g
during periods of their lives. (Single celled organisms have their cell get larger. Multicellular organisms add cells to become larger.)
Organisms also go through different stages of
d
.
Chapter 2 Section 2 Worksheet
All living things need f
in order to survive. They must produce their own or
capture and consume other organisms.
Some organisms such as plants are called p
their own food.
because they can produce
Like plants, most producers use the energy from the sun to produce their food by carrying
out p______________.
Organisms that get their food by feeding on other organisms are called c
.
Some consumers are d
. These organisms get their food by breaking
down the nutrients in dead organisms or animal wastes.
The cells of all organisms are made up of approximately ____%
live without water for about ___ days.
A
water. We can only
is a mixture of gases, mainly nitrogen, oxygen and some carbon dioxide.
Plants take in c
by-product.
d
and carry out photosynthesis and release oxygen a
All organisms must have somewhere to live that contains all the things they need to
survive. This “somewhere is known as h
.
What would a 100 kg organism’s mass be if there were no water?
Give an example of a producer, consumer, and decomposer.
Chapter 3 Section 3 Reading Worksheet
GPS: S7L2
All living things are made of cells, but what are cells and non-living things made of?
They are made of tiny building blocks known as a
.
A substance made of only one type of atom is called a e
atoms join together, they form an m
.
. When two or more
The six elements that are found in different combinations with each other and make up
living things are:
Proteins are large molecules made up of a
Simple c
together.
Complex c
a
.
(simple sugars) are made of one sugar molecule or a few linked
are made of hundreds of sugar molecules linked together.
At room temperature, fats are solid and oils are liquid.
A membrane surrounds all cells. This membrane is composed of a double p
layer.
Nucleic acids are composed of subunits called n
.
D
is a nucleic acid and contains all of the information to make the proteins that
cells need.
All cells need fuel and this fuel is in the form of A
Explain the difference in the two types of carbohydrates.
What are two functions of lipids?
How does an organism use proteins?
(adenosine triphosphate).