· Endosymbiosis- “inside relationship”
This is the theory that prokaryotes ate other prokaryotes but instead of dying
these eaten prokaryotes developed a mutualistic relationship with the
prokaryote that ate them. They became organelles. AND now that the
prokaryotes had organelles they are Eukaryotes.
Proof—the mitochondria and the chloroplast have their own DNA separate
from the nuclear DNA. Also they will reproduce themselves.
· Charles Darwin- often called the Father of Evolution.
He first came up with the idea that perhaps species change through time and
came from one common ancestor. He developed the idea of Natural Selection.
Natural Selection- “survival of the fittest” But really it is that the organism who
can best reproduce gets to pass on more of its genes and traits.
Darwin developed this theory when he traveled to the Galapagos islands. He studied finches and was able to see that perhaps they had a common ancestor even though they had different beaks.
Darwin was able to show that either a species will adapt to its environment or it will die. And that the organism with the best adaptation will reproduce the most to pass this adaptation on to future generations.
A population can change due to natural selection. Classic example is of the dark and light moths. At first there were more light colored moths on light trees. But when pollution came and changes the trees the light ones were eaten and the dark ones survived. As the trees got darker so did the moths.
· Due to natural selection our pests are becoming resistant to pesticides and our bacteria are becoming resistant to antibiotics (medicines). Only the weak ones were killed off which left the strong and resistant ones to reproduce which is now all we have.
· Camouflage- when an organism blends in with its surroundings
Mimicry- when a harmless organism acts or looks like a harmful one.
(remember the chocolate).
Classic mimicry example- the monarch butterfly is poisonous to birds and the
viceroy is not. But the viceroy looks like the monarch the birds do not eat it.
Camouflage and mimicry help organisms because it allows them to survive to
reproduce—natural selection.
How do new species evolve?
· Sometimes a part of a species is separated from the rest of the group either by a highway, mountains, ocean, or any other physical barrier. This is called geographic isolation.
Once they have been separated for a long time each group will change with their
environment—natural selection again.
· This will result in them being so different that even if they were to come back together again they could not mate. This is called reproductive isolations. This can be because their bodies no long match up or perhaps their social behaviors are now different (mating seasons or mating rituals).
· When the two can no longer mate they are now two different species and this creation of a new species is called Speciation.
(remember the mice on the video and the M&Ms)
There are four major evolution patterns:
· Adaptive Radiation- when several different species of organisms evolve from one common ancestor.
· Divergent Evolution- this is when changes cause species to branch off from each other. Results in different species from a common ancestry.
For both adaptive radiation and divergent evolution the closer they are together on the
map the closer related they would be. The oldest species branched off first.
· Convergent evolution- this is when unrelated species evolve similar traits because they live in similar environments. Ex. bird, bat, and butterfly wing
· Coevolution- this is when two different and unrelated species evolve characteristics that compliment each other. Or help each other out. Ex. Bumble Bee and Flower. Both have traits that attract the other and they evolved these traits so they could have a mutualistic relationship.
· Cladogram- a tree like map which shows the evolutionary relationships of organisms
· There are several different “proofs” for evolution:
Fossils- show how organisms changed through time and can show
relationships.
Fossils can be dated in two ways- relative or radiometric dating
Anatomical- by comparing the anatomy
or body structure of organisms we
can determine how closely related they are.
· Biochemical similarities- by comparing the DNA or the Amino Acids in protein we can determine how closely related organisms are. They closer their DNA and proteins are they closer related they are.
(remember comparing the horse, human, and gorilla).
Classification
· First classification system was developed by Aristotle, but it had a few problems.
· The modern day classification that we use today was
developed by Carolus Linnaeus.
He classified organisms on their body structure and on many different characteristics.
· There are 8 levels of classification
Did Domain
King Kingdom
Philip Phylum
Come Class
Over Order
For Family
Good Genus
Spaghetti Species
· The largest and most general or broad classification would be the Domain and Kingdom.
· The smallest and most specific classification is the species. Organisms can only interbreed if they are in the same species.
· The naming system we use today was also developed by Linnaeus. It is called Binomial Nomenclature= the 2 name naming system. It is written in Latin.
Common names can often be confusing so scientists use the
scientific name. This name has two parts = the genus and species.
Genus is always capitalized. The species in not capitalized.
The whole thing is in italics or underlined.
If two organisms are in the same genus it means they are related.
· Dichotomous Key—this is like scavenger hunt to find out the scientific name of an organisms
· There are 6 kingdoms and you must know the characteristics of each:
Domain: / Eukarya / Bacteria / ArchaeKingdom: / Animal / Plant / Fungi / Protist / Eubacteria / Archaebacteria
Cell type / Eukaryote / Eukaryote / Eukaryote / Eukaryote / Prokaryote / Prokaryote
Movement? / yes / no / no / yes / yes / yes
Uni or Multi / Multi / Multi / Multi
Uni-yeast / Multi
Uni / Uni / Uni
Hetero or Auto / Hetero / Auto / Hetero-
absorb / Hetero
Auto / Hetero
Auto / Hetero
Auto
Cell wall / no / Yes-cellulose / Yes- chitin / sometimes / Yes- peptidoglycan / Yes- cellulose
Reproduction / sexual / Sexual
asexual / asexual / asexual / Asexual- binary fission / Asexual-
Binary fission
Animal Kingdom:
· Annelids- the segmented worms
Ex. Earthworm or leech
Body structure- is an invertebrate and has segments called Septa
Circulatory system- has a closed system which means it has veins and arteries
Respiration- they can breathe through gills or through their skin
Digestive system- the eat through a pharynx and eat decaying matter (decomposer)
Movement- the move by contracting muscles like an inch worm. The trails that they make through the soil help plants with water and oxygen for the roots.
Reproduction- asexual or external fertilization
· Insects- an arthropod with three body parts and 6 legs (remember the song)
They have an exoskeleton- a hard outer covering instead of having bones. It
provides them with structure and support.
Reproduction- sexual
Circulatory system- open
Respiration- they breath through tubes in their abdomen
All insects will change throughout their life and this is called Metamorphosis
There are two types of metamorphosis:
Complete- eggs—larva—pupa—adult
Ex. Butterfly and cocoon
Incomplete- egg---nymph—bigger nymph—adult
ex. Grasshopper
· Amphibians-
Reproduction- sexual
Circulatory system- closed.
First they have 2 chambers in their heart and then three
They have moist skin which they partly breathe through it. Have lungs
Their eggs are moist and must be kept in or near water. They have no shell.
Ex. Salamander and frogs
Ectotherms—meaning cold blooded
They have a backbone so they are vertebrates and Chordates.
· Mammals
Reproduction-- sexual
Circulatory system—closed
They have 4 chambered hearts.
They have hair or fur, give live birth and feed their young milk.
Endotherms—warm blooded
Ex. Human or dog
Placenta- when the baby is in the womb of a mammal it is attached to the
mother through a placenta. This provides the baby with nutrients and
oxygen from the mother and gets rid of the baby’s waste.
Protists Kingdom:
There can be animal or plant like protists
The Animal like protists (protozoans)-
Heterotrophs (protozoans)- absorb their food
oral and anal pore- a crude mouth and butt
Autotrophs (Euglena-plant like) – use photosynthesis
Reproduction- they usually reproduce asexually
a. spores- which are like eggs that don’t have to be fertilized
b. binary fission
Malaria—
This disease is caused by a plasmodium (a type of protist). It is transferred to humans by a mosquito. The protist spends some part of its life in the liver cells and some time of its life in the blood cells. This is why people with sickle shaped blood cells (sickle cell anemia) are resistant to the disease.
Plants--- Plants evolved from plant like protists
· Vascular tissue- this is like the plant’s cardiovascular system.
There are two types: Xylem- carries water up the plant
Phloem- carries sugar down the plant
Pollination- when pollen lands on the female part of the flower. Often a pollinator (bird or insect) helps with this.
Fertilization- when the sperm of plant reaches the plant’s ovary. This results in a seed.
Germination- when a seed begins to grow into a seedling.
Cross section of a leaf:
Viruses
They are not thought to be alive because they do not carry out all life functions.
They have a capsid (a protein coat)
with DNA or RNA on the inside.
Viruses usually have the word-phage at the end of their name.
Ex. Bacteriophage is a virus which infects bacteria
There are two life cycles for viruses:
Lytic cycle- the virus injects its DNA into the cell.
The cell starts making viruses inside of it.
Soon the cell will burst open or lyse releasing new viruses.
Lysogenic cycle- in this cycle the virus DNA is inserted into the host DNA and then just waits. It could stay in the lysogenic cycle for a short or long time. Eventually this will turn into the lytic cycle when the cell starts to make new viruses.
HIV- this virus is different than any other. Normally our immune system can fight back and eventually get rid of the virus. But HIV actually attacks the immune system and destroys it. So then the body has no defense.
Immune System
· Antigens- foreign invaders in the body. Bacteria, viruses, etc.
· Pathogen- an organism that can make you sick
· T cells- cells in our bodies that work to destroy bacteria or viruses
· B cells- these will release antibodies which will attach to a virus and disable it
· Memory B cells- your body remembers every virus you have ever had. When you get the same virus again the memory cell will recognize it and order an attack before you can get sick.
· Vaccine- this is when you are given a weakened or dead virus. This allows your body to “remember” a virus that never actually made you sick. It prevents you from ever getting truly sick.
· Antibiotic- this is a medicine which will kill bacteria
· Active immunity- this is immunity or resistance that a person has because they have actually had the disease. You can also get this from a vaccine.
Ex. You have had chicken pox so now you have active immunity against it or
you get a vaccine against chicken pox.
· Passive immunity- this is when you are immune from a virus that you never actually had. Mothers can pass this on to their children when they breastfeed them.
Animal Behavior
· There are two types of behaviors:
a. learned- behaviors we will not know until we learn them
b. innate- behaviors that we are born with and know one has to teach us
· There are several innate behaviors:
Instinct- this is a simple innate behavior such as a reflex
Suckling instinct- this is when a baby automatically knows how to suckle or drink milk from the mother’s breast
Courtship – this is mating behavior
Territorial defense- protection of an animal’s behavior
Estivation- this is like hibernation in the summer time. Frogs do this in the desert to protect themselves from the summer heat of the desert
Hibernation- deep sleep in the winter time
Migration- when birds or other animals leave the north and move to the south for the winter and then come back in the summer
Circadian rhythm- an animal’s natural body clock or rhythm. This is an animal’s natural clock to eat and sleep.
· Types of learned behavior:
Taxes (taxis)- this movement. Positive taxes is moving towards and negative taxes is moving away. Ex. Euglena have a positive phototaxis…meaning they move towards the light.
Imprinting- this happens mainly in birds. The first animal or object that the new born bird sees, the bird forever sees as its mother.
Habituation- becoming so used to something that you cease to be bothered by it or notice it.
Ex. not noticing your ceiling fan anymore or a train that passes by your house
Classical conditioning- this is making unrelated things become associated. Pavlov rung a bell every time he fed his dogs. So then the dogs learned to associate bell ringing with food even if no food as around. Ex. can opener with your cat or dog
Trial and error- trying something over and over again and learning from your mistakes.