Transcript Honors Marine Biology Class Four

Marine Biology
Life in the Sea
Part 2
September 9, 2014
Module 2
Class Challenge
Share a line from your
Favorite Movie
Quiz # 3
List Levels of Organization in Living Systems
(Smallest to Largest)
Levels of Organization in
Living Systems
Atom –
The smallest unit of an element
Molecule –
A chemical unit that results from atoms bonding together
Cellular Organelle – A well defined structure within a cell
Cell The basic organizational unit of living material
Tissue –
A grouping of similar cells with a specific function
Organ –
A body part made of tissues performing as a unit
Organism –
An individual capable of reproduction
Population –
A group of interbreeding organisms coexisting together
Community –
Integrated populations living in a limited area
Ecosystem –
A community and the physical features of its environment
Diversity of Life
http://youtu.be/wxjSx9wluAQ
Wet Lab at South Lido
A Tour of the Cell
Bozeman Science: John Anderson
http://youtu.be/1Z9pqST72is
• There are two major kinds of prokaryotes:
• Bacteria
• Archaea (single-celled organisms)
• Biologists now estimate that each human being
carries nearly 20 times more bacterial, or
prokaryotic, cells in his or her body than human,
or eukaryotic, cells.
• If that statistic overwhelms you, rest assured that
most of these bacteria are trying to help, and not
hurt, you. Numerically, at minimum, there are 20
times more prokaryotic cells on Earth than there
are eukaryotic cells.
• This is only a minimum estimate because there
are trillions of trillions of bacterial cells that are
not associated with eukaryotic organisms.
• all Archaea are also prokaryotic. As is the
case for bacteria, it is unknown how many
Archaean cells are on Earth, but the
number is sure to be astronomical. In all,
eukaryotic cells make up only a very small
fraction of the total number of cells on
Earth.
There are four main structures
shared by all prokaryotic cells,
bacterial or Archaean:
•
The plasma membrane
•
Cytoplasm
•
Ribosomes
•
Genetic material (DNA and RNA)
Some prokaryotic cells also have
other structures like:
• the cell wall,
• pili (singular pillus), and
• flagella (singular flagellum).
• Each of these structures and cellular
components plays a critical role in the
growth, survival, and reproduction of
prokaryotic cells.
There are big differences between
eukaryotic and prokaryotic cells, but
they do have some things in common:
1. Both have DNA as their genetic material.
2. Both are encased in membranes. The
membranes of Prokaryotic cells and of
some eukaryotic cells are surrounded by
a strong cell wall.
3. Both have a similar basic metabolism
(the word metabolism refers to the
formation and break down of chemicals
in the body).
• The major difference is that eukaryotes
have a nucleus and prokaryotes do not.
• Prokaryotes – no nucleus – think before
the egg.
Eukaryotic Cell
You are a eukaryote and have eukaryotic
cells.
A cell is defined as eukaryotic if it has
a membrane-bound nucleus. Any
organism composed of eukaryotic cells is
also considered a eukaryotic organism.
Case in point: You.
Biologists do not know of any single
organism on Earth that is composed of
both eukaryotic and prokaryotic cells.
However, many different types of prokaryotic
cells, usually bacteria, can live
inside larger eukaryotic organisms.
Creepy, but true.
All of the organisms we can see with the
naked eye are composed of one or more
eukaryotic cells, with most having many
more than one.
This means that most of the organisms we
are familiar with are eukaryotic.
However, most of the organisms on Earth,
by number, are actually prokaryotic.
Here are some examples of
eukaryotes:
• Animals
• Plants
• Fungi (mushrooms, etc.)
• Protists (algae, plankton, etc.)
• Most plants, animals, and fungi are
composed of many cells and are, for that
reason, aptly classified as multicellular,
• while most protists consist of a single cell
and are classified as unicellular.
All eukaryotic cells have
•
A nucleus
•
Genetic material
•
A plasma membrane
•
Ribosomes
•
Cytoplasm, including the cytoskeleton
Most eukaryotic cells also have
other membrane-bound internal
structures called organelles.
• Organelles include
• Mitochondria
• Golgi bodies
• Lysosomes
• Endoplasmic reticulum
• Vesicles
There are a few major differences
between animal, plant, fungal, and
protistan cells,
All plant cells have
• A cell wall made of cellulose
• A large central vacuole
• Chloroplasts
Some animal and protistan cells
have
•
Flagella
•
Cilia
All animal cells have
•
Centrioles
All fungal cells have
• cell wall made of chitin.
The nucleus in the cell is analogous to
the brain in the body. It is a control
center for a cell.
The nucleus stores all the information the
cell needs to grow, reproduce, and
function.
This information is contained in long but thin
molecules of deoxyribonucleic acid, or
DNA.
One of the functions of the nucleus is to
protect the cell’s DNA from damage, but
that is not all that it does. The nucleus is
basically a large membranous sac.
The nucleus also contains a small round body
called a nucleolus that holds nucleic acids and
proteins.
The nuclear membrane has pores through which
the contents of the nucleus communicate with
the rest of the cell.
The nuclear membrane tightly controls what gets
into the nucleus and what gets out. This
regulation of communication by the nuclear
membrane has a great effect on what a cell
looks like and what it does.
Chromosomes are also located in the nucleus and
are basically organized structures of DNA and
proteins.
In eukaryotes, the chromosomal DNA is packaged
and organized into a condensed structure called
chromatin.
Chromosomes are single pieces of DNA along with
genes, proteins, and nucleotides, and chromatin
is a condensed package of chromosomes that
basically allows all the necessary DNA to fit
inside the nucleus.
In eukaryotic organisms, the DNA inside the
nucleus is also closely associated with large
protein complexes called histones.
Along with the nuclear membrane, histones
help control which messages get sent from
the DNA to the rest of the cell.
The information stored in DNA gets
transferred to the rest of the cells.
• The cytoplasm in eukaryotic cells is a gel-like, yet fluid,
substance in which all of the other cellular components
are suspended, including all of the organelles.
• The underlying structure and function of the cytoplasm,
and of the cell itself, is largely determined by the
cytoskeleton, a protein framework along which particles
in the cell, including proteins, ribosomes, and organelles,
move around.
• You can think of the cytoskeleton as a type of 3D
"highway system" with roads running in every direction,
including up and down. The cytoplasm is the thick fluid in
which the "highway system" is suspended and through
which cellular materials are transported.
• Helpful tip: Whenever you see "cyto" as part of a word,
think "inside the cell."
Eukaryotic Cell
• Eukaryotic cells contain a wide variety of
organelles (tiny "organs" or structures
inside the cell) that perform various
functions.
• Some of the most important organelles are
mitochondria, chloroplasts, lysosomes
and ribosomes.
The basic structure of an
eukaryotic cell:
• The membrane (the outside or coating)
• The nucleus (the place where the DNA is stored
and from where instructions are sent to the rest
of the cell for the production of proteins. The
nucleus has its own membrane)
• The cytoplasm or cytosol, which contains
everything between the membrane and the
nucleus (including organelles)
• Eukaryotic cells are, on average, ten times
as large as prokaryotic cells.
• Their DNA is more complex and is formed
into chromosomes.
• And their organelles enable them to do
more complex jobs.
• Most plants are made up of eukaryotic
cells.
• But eukaryotic plant cells are different from
eukaryotic animal cells.
• And the biggest difference is the cell
membrane.
• In animals (like us) the membrane is the
actual outside of the cell.
• But plants have something extra -- a cell
wall that goes all the way around the
outside of the membrane, shown with the
brown shading (see Figure 2.3, page 39)
• The main difference between plant cells and
animals cells is this -- plant cells have a cell
wall and animal cells don't.
• This cell wall is made of cellulose.
• Cellulose is important in human nutrition since it
provides fiber (roughage), which keeps your
digestive system going. That's why it's important
to eat a diet rich in plant material like fruits,
whole grains and vegetables.
Levels of Organization in Living
Systems: Table 2.1
Atom
Molecule
Cellular Organelle
Cell
Tissue
Organ
Organism
Population
Community
Ecosystem
Life in the Blue Really HD BBC
Beautiful Ocean Life
http://youtu.be/LL59es7iy8Q
Challenges that Marine organisms
have in their ecosystem
Of course their habitat is the Ocean. Life is
abundant and found in all areas of the sea.
But oceans are vast and varied.
How are the oceans around the earth
different….???
Ocean animals have special features that enable
them to survive in the unique conditions of their
environment.
Barnacles attach to solid rock and withstand the
surge of rough waves.
Some fish can live among the poisonous tentacles
of jellyfish;
Large whales feed on microscopic plankton in
wide, open-ocean areas;
Flounder lay flat on the ocean floor, perfectly
matching the color and texture of sand.
Some special features of marine organisms
have to do with keeping their bodily
conditions stable.
In the ocean, marine organisms have to
survive in a medium that could disrupt
their internal metabolism, so they must
maintain a fairly constant internal condition
to survive. This is called homeostatis.
Homeostatis
Defined as the tendency of living organisms
to control or regulate changes in their
internal environment.
Poikilotherm
• An organism whose body temperature
changes with its surrounding environment.
• It is the opposite of a homeotherm, an
organism which maintains thermal
homeostasis.
Homeotherm
An animal that maintains a controlled
internal body temperature using its
own heating and cooling mechanisms.
warm-blooded is a colloquial term to
describe animal species
that have a relatively higher
blood temperature, and maintain
thermal homeostasis primarily
through internal metabolic
processes. These are
characteristics of mammals
and birds.
Ectotherm
An organism whose body temperature is
controlled by its surrounding environment.
Endotherm
An animal whose internal body temperature
is a result of internal sources of
heat. (birds, mammals, some fishes and
insects, and even some plants)
Homeotherm and Endotherm
• One internal source of heat comes from their
muscles. Heat is generated from muscle activity
and is released into their internal tissues as a
means of warming them.
• Another source of heat is controlled by their rate
of respiration. If an organism can increase its
respiration, it will make more heat from the
burning of fats and other molecules.
• This is an advantage in that these
organisms can maintain a warm body
temperature in cold water and remain very
active.
• At the same time, higher respiration rates
use up lots of energy. Many of these
animals are insulated with thick layers of
blubber, hair, or feathers so that only small
increases in respiration are needed to
warm their internal temperatures.
See Figure 2.4 (Page 46)
• Angelfish
• Shark
• Dolphin
Experiment 2.3: The Cell
Objective: To be able to identify prokaryotic
cells and Eukaryotic cells.
Supplies:
Microscope
Prepared Slides
Experiment 2.3: The Cell
The Prokaryotic Cell
The vast majority of cells on Earth are
actually prokaryotic,
There are two major kinds of
prokaryotes:
• Bacteria
• Archaea (single-celled organisms)
There are four main structures shared
by all prokaryotic cells, bacterial or
Archaean:
•
The plasma membrane
•
Cytoplasm
•
Ribosomes
•
Genetic material (DNA and RNA)
Some prokaryotic cells also have other structures:
the cell wall,
pili (singular pillus),
flagella (singular flagellum).
Each of these structures and cellular components
plays a critical role in the growth, survival, and
reproduction of prokaryotic cells.
Experiment 2.3: The Cell
The Eukaryotic Cell
Homework
1.
2.
3.
4.
5.
6.
7.
Complete OYO questions for Module 2 to 2.12;
Complete Study Guide for Module 2;
Finish Experiment 2.4: The Cell
Module 2 Test;
Read Module 3: Pages 55-65
Quiz on the parts of the cell
Notebook check through Module 2
8.
Further Study: http://www.shmoop.com/biologycells/all-eukaryotic-cells.html