Post on 16-Jan-2016
Fundamentals of BiologyFundamentals of Biology
Shipley’s Marine BiologyShipley’s Marine Biology
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: Carbohydrates Proteins Lipids Nucleic acids
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 energy for organisms.
Some are used to store energy to be used later (like starch found in plants and some algae.
Some are used in structure such as chitin found in the shells of some animals (like crabs, lobsters and shrimp) or cellulose found in plants.
The Essential Building Blocks of Life
Proteins:
– Composed of smaller units known as amino acids
– Enzymes are specialized proteins necessary for chemical reactions in an organism
– Some proteins are hormones that act as chemical messengers within an organism
– Others can be used in structure, immunity, internal transport among other duties
The Essential Building Blocks of Life
The Essential Building Blocks of Life Lipids:
Lipids are mainly hydrophobic (do not mix with water – 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 lipid (fat) underneath the skin for insulation.
Many lipids are used for energy storage within an organism.
They can also be used for internal structure or as hormones.
Nucleic Acids:
Made of smaller units called nucleotides. DNA and RNA are nucleic acids. DNA is the molecule of heredity; it provides the
instructions for making every part of an organism.
RNA helps with this duty in multiple ways.
The Essential Building Blocks of Life
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.
The source of carbon for building carbohydrates is carbon dioxide; oxygen is released as a by-product
Whether an organism makes their own
carbohydrates (autotrophs) or gets carbohydrates by eating other organisms (heterotrophs), they still must break down the carbohydrates within their cells for energy.
This process is known as cellular respiration.
Respiration consumes oxygen and produces carbon dioxide and water as by-products.
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
Energy and Life
All living organisms can be divided into two
basic groups based on cellular composition:
1. Prokaryotic2. Eukaryotic
Types of Organisms
Prokaryotic Organisms:
Lack a nucleus Posses ribosomes Contain a circular ring of DNA 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 nucleus Posses many specialized organelles (look at
organelles in Fig. 4.8) Eukaryotic organisms can be unicellular or
multicellular
Types of Organisms
Mitochondria- site of cellular respiration Golgi complex and endoplasmic reticulum-
manufacture, package and transport cellular products such as proteins (Vesicles – transport things from one place to another.)
Ribosomes- manufacture proteins Chloroplasts- site of photosynthesis Vacuole- storage of water and nutrients Centrioles- assist in movement of
chromosomes during cellular reproduction
Example Organelles in Eukaryotic Organisms
Atom – fundamental unit of all matter
Molecule – 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
Tissue – group of cells functioning as a unit
Organ – many tissues arranged into a structure with a specific purpose in an organism
Levels of Organization in Living Organisms
Organ system – group of organs that work
together
Whole organism (individual)
Levels of Organization in Living Organisms
Population – group of organisms of the same
species occurring in same habitat
Levels of Organization in Living Organisms
Community – all species that exist in a
particular habitat (ex: all the organisms on a coral reef)
Ecosystem – combination of the community and the physical environment
Levels of Organization in Living Organisms
Solutes (substances dissolved in water) will move
from areas where they are more concentrated to an area where they are less concentrated
This movement is called diffusion Movement of water from an area where it is more
concentrated to an area where it is less concentrated through a semipermeable membrane is called osmosis.
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
Diffusion and Osmosis
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
Regulation of Solute/Water Balance
Go to www.cellsalive.com/
In the left-hand column labeled “Interactive,” click “Puzzles”
On the “Cells Alive! Puzzle Page,” complete both “Animal Cell” and “Plant Cell” Jigsaw puzzles. Upon completing the puzzle, right click the mouse, and
click “PRINT”. On the same page, under “Word Puzzles,” complete
“Cell Structure #1” and “Cell Structure #2.” Again, upon completing each puzzle, print finished
puzzle.
Homework Assignment
Ectotherms
Generate body heat metabolically, but cannot maintain constant internal body temperature
Examples: snakes, lizards, frogs, insects Poikilotherms
Body temperature mimics the surrounding environment. They do not use their metabolisms to heat or cool themselves.
Many ectotherms are poikilotherms. Examples: fish, reptiles
Temperature Control
Endotherms
– Generate body heat metabolically and body temperature does not match the temperature of the surrounding environment
– All birds and mammals
Homeotherms– These organisms retain metabolic heat and can control
metabolism to maintain a constant internal temperature– Homeotherms are endotherms
Temperature Control
Asexual reproduction
– Does not involve mating of two individuals– Young are produce by a single parent organism– The young produced are genetically identical to
the parent
Modes of Reproduction
Examples of Asexual Reproduction
Fission – the splitting of one organism into two smaller organisms of equal size
Budding – the organism develops buds (small clones) that eventually break off and become another organism
Vegetative reproduction – a plant reproduces new individuals by sending an underground stem (rhizome) sideways from which new plants will sprout
Modes of Reproduction
Sexual reproduction
Normally involves two individuals Parent individuals produce gametes (eggs or
sperm) that unite to produce a new, genetically unique individual
Ovaries are the organs that produce eggs Testes are the organs that produce sperm
Modes of Reproduction
Many marine organisms release their eggs
and 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
Modes of Reproduction
Hermaphrodites – individuals that have
male and female reproductive tissues either simultaneously or at different phases during the life. Examples: Protandry- an individual spends the first portion
of the life as a functional male then becomes a female later in life after some cue initiates the change
Protogyny- an individual spends the first portion of the life as a functional female then becomes a male later in life after some cue initiates the change
Modes of Reproduction
Evolution 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 above-average intelligence) can give one individual survival advantage over others in his/her population.
Evolution and Natural Selection
These advantages can be translated
into 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 natural selection.
Evolution and Natural Selection
Natural selection therefore strengthens the
gene pool of a species by eliminating less advantageous traits through lack (or reduction) of reproductive events in these individuals.
Evolution and Natural Selection
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 Kingdom Phylum Class Order Family Genus Species
Taxonomy
There can be millions of different organisms
in a domain or kingdom, while a species by definition is just one type of organism.
So, what defines a species? Common characteristics and the ability to breed successfully with other members of their species (biological 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).
Taxonomy
Phylogenetics is defined as the study of
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.
Phylogenetics