Transcript chapt04 discussion

Chapter 4
Fundamentals of Biology
The Essential Building Blocks of Life
• Just like water is a molecule, there are other
•
molecules important to life.
Four organic (contain carbon, hydrogen and
oxygen) molecules make up living organisms:
1.
2.
3.
4.
The Essential Building Blocks of Life
• Carbohydrates:
– Made of carbon, hydrogen and oxygen at a 1:2:1
ratio (example: glucose is C6H12O6).
– Most carbohydrates are used for ____ for organisms.
– Some are used to store energy to be used later (like
_____ found in plants and some algae).
– Some are used in structure such as ____ found in the
exoskeletons of some animals (like crabs, lobsters
and shrimp) or ____ found in plant cell walls.
The Essential Building Blocks of Life
• Proteins:
– Composed of smaller units known as ____
– ____ are specialized proteins necessary for
chemical reactions in an organism
– Some proteins are ____ that act as chemical
messengers within an organism
– Others can be used in structure, immunity,
and internal transport among other duties
The Essential Building Blocks of Life
• Lipids:
– Lipids are mainly hydrophobic (____)
– remember the saying that oil and water don’t mix.
– Due to this principle, many marine organisms use a
coating of lipid to cover fur or feathers which provides
an insulating layer.
– Some also have a layer of ____ underneath the skin
for insulation.
– Many lipids are used for _____ storage within an
organism.
– They can also be used for internal structure or as
hormones.
The Essential Building Blocks of Life
• Nucleic Acids:
– Made of smaller units called _____.
– ____ and ___ are nucleic acids.
– DNA is the molecule of heredity; it provides
the instructions for making every part of an
organism. Parts are made of ____
– RNA helps with this duty in multiple ways.
Energy and Life
• Many organisms use sunlight to drive the
process of photosynthesis.
• In photosynthesis, plants, algae and other
autotrophs use pigments to capture the energy
in sunlight.
• This energy is used to build carbohydrates.
What is basic chemical reaction for photosyntheis?
Energy and Life
• Whether an organism makes their own
carbohydrates (____trophs) or gets
carbohydrates by eating other organisms
(____trophs), they still must break down the
carbohydrates within their cells for energy.
• This process is known as cellular respiration.
What is the basic chemical reaction for cellular
respiration?
Energy and Life
• Some of the carbohydrates made by
photosynthetic organisms are converted
into other types of molecules such as:
– Proteins
– Lipids
– Nucleic acids
Energy and Life
• When these autotrophs make more energy
than they can use, the excess is called
primary production
• Organisms responsible for this primary
production are called primary producers
• Marine organisms are a major source of
worldwide primary production
Energy and Life
• Marine organisms require nutrients to
convert carbohydrates to other types of
molecules
• These nutrients can include minerals,
vitamins and even raw elements
• Ex: silica is required to make the shell of
some organisms
Types of Organisms
• All living organisms can be divided into
two basic groups based on cellular
composition:
1. Pro____
2.
Types of Organisms
• Prokaryotic Organisms:
– Lack a ____
– Posses ribosomes
– Contain a circular ring of ____
– Some may also have plasmids, extra pieces of
DNA
– Cell wall is normally present
– May have a flagellum
– Unicellular
Types of Organisms
• Eukaryotic Organisms
– Possess DNA enclosed inside a _____
– Posses many specialized organelles (look at
organelles in Fig. 4.8)
– Eukaryotic organisms can be unicellular or
multicellular
Example Organelles in Eukaryotic
Organisms
• Mitochondria- site of ____
• Golgi complex and endoplasmic reticulum•
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manufacture, package and transport cellular
products such as ____
Ribosomes- manufacture ____
Chloroplasts- site of ____
Vacuole- storage of water and nutrients
Centrioles- assist in movement of ____ during
cellular reproduction
Levels of Organization in Living
Organisms
• Atom – fundamental unit of all matter
• ____ – two or more atoms chemically
joined together
Levels of Organization in Living
Organisms
• Organelle – specialized features of cells
• Cell – basic unit of life
Levels of Organization in Living
Organisms
• ____ – group of cells functioning as a unit
• ____ – many tissues arranged into a
structure with a specific purpose in an
organism
Levels of Organization in Living
Organisms
• ____ – group of organs that work
together
• Whole organism (individual)
Levels of Organization in Living
Organisms
• ____ – group of organisms of the same
species occurring in same habitat
Levels of Organization in Living
Organisms
• ____ – all species that exist in a particular
habitat (ex: all the organisms on a coral
reef)
• ____ – combination of the community and
the physical environment
Diffusion and Osmosis
• Solutes (substances dissolved in water)
will move from areas where they are more
concentrated to an area where they are
less concentrated is called ____
• Movement of water from an area where it
is more concentrated to an area where it
is less concentrated is called ____
Diffusion and Osmosis
• Since marine organisms live in a very
solute-rich environment, they have a
tendency to gain solutes and lose water
• This can result in the death of cells if the
water loss/solute gain is significant
• These organisms must find ways to deal
with this diffusion and osmosis
Regulation of Solute/Water Balance
• Osmoconformers– Do not attempt to control solute/water
balance
– Their internal concentration varies as the
salinity in the water around them changes
– Most can only tolerate a very narrow range of
salinity
Regulation of Solute/Water Balance
• Osmoregulators
– These organisms control their internal
concentrations
– Can generally tolerate a wider range of
salinities than osmoconformers
– This can be done in a variety of ways such as
secreting very little urine or using specialized
glands to secrete salts as examples
-marine fish drink sea water and secrete as little urine as possible; whereas
freshwater fish refrain from drinking water and secrete large amounts of dilute
urine
Temperature Control
Modes of Reproduction
• Asexual reproduction
– Does not involve mating of two individuals
– Young are produced by a ____ parent
organism
– The young produced are genetically ____ to
the parent
– Examples of single-celled organisms: Binary
fission in bacteria and mitosis in algae
Mitosis in a dinoflagellate
Modes of Reproduction
• Examples of Asexual Reproduction in
multicellular organisms:
– Budding – the organism develops buds (small clones)
that eventually break off and become another
organism Ex. Mushroom coral
– Vegetative reproduction – a plant reproduces new
individuals by sending an underground stem
(rhizome) from which new plants will sprout Ex.
Seagrass
Mushroom coral
Seagrass
Modes of Reproduction
• Sexual reproduction
– Normally involves ____ individuals
– Hermaphrodites – individuals that have both
male and female reproductive tissues
– Parent individuals produce gametes (eggs or
sperm) that unite to produce a new,
genetically unique individual
– ____ are the organs that produce eggs
– ____ are the organs that produce sperm
Modes of Reproduction
• Many marine organisms release their eggs and
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sperm directly into the water, this is known as
broadcast spawning.
For broadcast spawning to be effective, millions
of gametes must be released into the water at
roughly the same time to ensure fertilization will
occur
Many broadcast spawning species time the
release of their eggs to tides, moon phase,
water temperature, etc. to ensure success
Modes of Reproduction
• Other marine organisms rely on internal
fertilization, where a copulatory organ is
used to insert sperm directly into the
female’s reproductive tract
• This method requires contact between
parent individuals, but less gametes are
required for success
Evolution and Natural Selection
• ____ is defined as a change in the genetic
make-up of a population over time
• In the wild, any genetically derived traits
(such as faster swimming or aboveaverage intelligence) can give one
individual survival advantage over others
in his/her population.
Evolution and Natural Selection
• These advantages can be translated into
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reproductive advantage as well.
If one organism is better survivor, more of their
gametes will make it into the next generation in
a population.
Those individuals that are less advantaged may
not survive to reproduce or will reproduce less.
This is known as ____.
Evolution and Natural Selection
• Natural selection therefore strengthens
the gene pool of a species by ____ less
advantageous traits through lack (or
reduction) of reproductive events in these
individuals.
Taxonomy
• Taxonomy is the science of classifying and
naming organisms.
• This classification is done by a variety of
methods including DNA and protein
analysis, comparing embryos, looking at
the fossil record and comparing internal
and external body structures.
Taxonomy
• Taxonomy uses several levels of
classification shown below from the
largest (most species inclusive) to the
smallest (only one species):
• Domain  ___ Phylum  ____ Order
 Family  ____ Species
Taxonomy
• There can be millions of different organisms in a
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domain or kingdom, while a species by definition
is just one type of organism.
So, what defines a species? Common
characteristics and often the ability to breed
successfully with other members of their species
(____ species concept)
For example, there are 7 species of flounder
(fish) that exist in the southeast U.S. No matter
how much they look alike, they cannot breed
with each other and produce viable (functionally
reproductive) offspring (reproductive isolation).
Phylogenetics
• Phylogenetics is defined as the study of
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evolutionary relationships (relatedness) in
organisms.
Biologists may use many factors to determine
the relatedness of organisms such as structure,
reproductive patterns, embryological or larval
development, fossils, behavior or DNA/RNA.