AP BIO REVIEW: 4-24-03

Cladistics, Taxonomy, Plants, Photosynthesis

Implications of Cladistics

Understanding Branching Diagrams

The output from a phylogenetic analysis is a hypothesis of relationship of different taxa. This hypothesis can be represented as a cladogram, a branching diagram. Cladograms* bear a lot in common with the notion of family trees. In a family tree we trace back our ancestry. For example, in the family tree on the top right, the ancestors of all the rest of the family are the initial black dot and yellow square. These ancestors give rise to three children, one of which mates and has two children. We can all trace our lineages back to one set of ancestors.

All species have ancestors* too. So, for example, sometime in the past an ancestral species (father) of Homo sapiens walked the earth. This ancestor went extinct (died), but left descendent species (children). In family trees, we can talk coherently about real ancestors. In biology, the ancestors are often gone sometimes without a trace. All we have left are the children. Reading cladograms is much like reading a family tree. Both are rich in information. Cladograms, like family trees, tell the pattern of ancestry and descent. Unlike family trees, ancestors in cladistics ideally give rise to only two descendent species. Also unlike family trees, new species form from splitting of old species. In speciation, it does not take two to tango. The formation of the two descendent species is called a splitting event. The ancestor is usually assumed to "die" after the splitting event.

In the first tree, labelled Cladogram A, notice the green dots. Each dot has a letter associated with it. The dots with letters are the nodes of the tree. The stems of the tree end with the taxa under consideration, represented by boxes. At each node a splitting event occurs. The node therefore represents the end of the ancestral taxon and the stems the species that split from the ancestor. The two taxa that split from the node are called sister taxa*. They are called sister taxa because they are like the siblings from the parent or ancestor. The sister taxa must each be more closely related to one another than to any other group because they share a close common ancestor. In the same way, you are most closely related to your siblings than to anyone else since you share common parents. Lets focus on Node C in Cladogram A. At the node, the ancestor goes extinct but leaves two siblings hypothesized to be humans and gorillas. Humans and gorillas are sister taxa and are more closely related to one another than either is to chimpanzees or baboons.

Working down the tree we come to node B. At this node the ancestor of the humans and gorillas split from the chimpanzees. Therefore the chimpanzees sister taxon is the human/gorilla ancestor. A sister taxon can be an ancestor and all its descedents. We call an ancestor plus all its descendents a clade. A cladogram shows us hypothesized clades*.

Finally we come to node A. Here, we find the splitting event that led to the baboons and the ancestor to the chimpanzees, humans and gorillas. By working our way down the cladogram we have learned the pattern of splitting. We have found out that chimpazees, humans and gorillas are more closely related to each other than to baboons. In this example, baboons are the outgroup*.

Now, how in the world did we manufacture Cladogram A? We mentioned that it was a hypothesis. What if it we chose another hypothesis like Cladogram B or Cladogram C? We would change the pattern of speciation events. In Cladogram B, humans and chimpanzees are sister taxa and in Cladogram C, chimps and gorillas are sister taxa.

Which of the three cladograms presented above is correct? None of the cladograms can be proved correct, but Cladogram B is the best supported of the three based on character data and is therefore hypothesized to best reflect the true branching pattern.

Manufacturing cladograms which show hypotheses of ancestry and descent requires that we analyze characters and find those characters that unite clades.

Continue your journey by selecting one of the topics below.

Taxonomy

Taxonomy: System of classification based upon similarities in structure.

Developed by: Linnaeus , a Swedish botanist in the 18th century. Linneaus used Latin names because they would not change over time.

Binomial Names     Genus + species   Ex: Musca + domestica "House Fly"The 5 Kingdoms: REALLY  6 NOW!!!

 

Name

Structure

Prokaryotic/
Eukaryotic

Monera (BACTERIA)

Unicellular

Prokaryotic

Protista (AMEBA)

Unicellular

Eukaryotic

Fungi

Multicellular

Eukaryotic

Heterotrophic....Ex:Mushrooms

Plants Autotrophic

Multicellular

Eukaryotic

Many Plants Perform Photosynthesis Within The Chloroplasts

Animals Heterotrophic

Multicellular

Eukaryotic

Heterotrophic
can be carnivorous, herbivorous or omnivorous.

# 6 ARCHAEBACTERIA   EX: Cyanobacteria

Unicellular 

Photosynthetic prokayotes

         

 


Archaea

Index to this page

These organisms are microscopic prokaryotes. When the first ones were discovered (in 1977), they were considered bacteria. However, when their ribosomal RNA was sequenced, it became obvious that they bore no close relationship to the bacteria and were, in fact, more closely related to the eukaryotes (including ourselves!) For a time they were referred to as archaebacteria, but now to emphasize their distinctness, we call them Archaea.

They have also been called Extremophiles in recognition of the extreme environments in which they have been found:

Most of the >250 named species that have been discovered so far have been placed in two groups:

Euryarchaeota

There are three main groups:

1. Methanogens

These are found living in such anaerobic environments as

They are autotrophic; using hydrogen as a source of electrons for reducing carbon dioxide to food and giving off methane ("marsh gas", CH4) as a byproduct.

4H2 + CO2 -> CH4 + 2H2O

Two methanogens have had their complete genomes sequenced:

[View the data]

2. Halophiles

These are found in extremely saline environments such as the Great Salt Lake in the U.S. and the Dead Sea. They maintain osmotic balance with their surroundings by building up the solute concentration within their cells.

3. Thermoacidophiles

As their name suggests, these like it hot and acid (but not as hot some of the Crenarchaeota!). They are found in such places as acidic sulfur springs (e.g., in Yellowstone National Park) and undersea vents ("smokers").

Crenarchaeota

The first members of this group to be discovered like it really hot and so are called hyperthermophiles. One, Pyrolobus fumaris, lives at 113°C (the boiling point of water at sea level is 100°C).

Many like it acid as well as hot and live in acidic sulfur springs at a pH as low as 1 (the equivalent of dilute sulfuric acid). These use hydrogen as a source of electrons to reduce sulfur in order to get the energy they need to synthesize their food (from CO2).

One member of the group, Aeropyrum pernix, has had its genome completely sequenced.

Other members of this group seem to make up a large portion of the plankton in cool, marine waters. As yet, none of these has been isolated and cultivated in the laboratory.

Evolutionary Position of the Archaea  http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/Archaea.html

 

The archaea have a curious mix of traits characteristic of

The table summarizes some of them.

Eukaryotic Traits

Bacterial Traits

  • single, circular chromosome
  • operons
  • no introns
  • bacterial-type membrane transport channels
  • Many metabolic processes
    • energy production
    • nitrogen-fixation
    • polysaccharide synthesis

What can we conclude from this collection of traits?

occurred after their line had diverged from the archaea.

The Origin of Life?

Their

have suggested that the archaea may be the little-changed descendants of the first forms of life on earth.

Economic Importance of the Archaea

Because they have enzymes that can function at high temperatures, considerable effort is being made to exploit the archaea for commercial processes such as providing

Archaea may also be enlisted to aid in cleaning up contaminated sites, e.g., petroleum spills.

Welcome&Next Search

17 May 2002

 

 

 

 

 

http://www.guilford.k12.ct.us/~faitschb/evolrev.html

 

Evolution review:

natural selection - facts and assumptions
darwins missing evidence
Galapagos Is. significance
source of new genes in a population
signs of evolution (evidence)
fossils
homologous structures
analogous structures
hardy weinberg theory and conditions
h-w problems
gene frequency
types of selection:

diversifying

stabilizing

directional
radiant adaptation
isolation
sympatric and allopatric speciation
punctuated equilibrium vs gradualism
Lamarck's erroneous theory
genetic drift

bottleneck effect

founder effect
species definition
gene pool
heterozygotes (hybrids)
rev. 1/9/2002

Taxonomy: Classifying Life

 

 

At least 1.7 million species of living organisms have been discovered, and the list grows longer every year (especially of insects in the tropical rain forest). How are they to be classified?

Ideally, classification should be based on homology; that is, shared characteristics that have been inherited from a common ancestor. The more recently two species have shared a common ancestor,

Until recent decades, the study of homologies was limited to

However, since the birth of molecular biology, homologies can now also be studied at the level of

Anatomical homology: an example

The figure shows the bones in the forelimbs of three mammals: human, whale, and bat (obviously not drawn to the same scale!). Although used for such different functions as throwing, swimming, and flying, the same basic structural plan is evident in them all. In each case, the bone shown in color is the radius.

Body parts are considered homologous if they have

It seems unlikely that a single pattern of bones represents the best possible structure to accomplish the functions to which these forelimbs are put. However, if we interpret the persistence of the basic pattern as evidence of inheritance from a common ancestor, we see that the various modifications are adaptations of the plan to the special needs of the organism. It tells us that evolution is opportunistic, working with materials that have been handed down by inheritance.

Embryonic Development

The embryonic development of all vertebrates shows remarkable similarities as you can see from these drawings (supplied by Open Court Publishing Company). The drawings in the top row are of the embryonic stage called the pharyngula. At this stage ("I") they all contain a:

The branchial grooves are matched on the inside by a series of paired gill pouches. In fishes, the pouches and grooves eventually meet and form the gill slits, which allow water to pass from the pharynx over the gills and out the body.

In the other vertebrates shown here, the grooves and pouches disappear. In humans, the chief trace of their existence is the eustachian tube and auditory canal which (interrupted only by the eardrum) connect the pharynx with the outside of the head.

Recapitulation

The idea that embryonic development repeats that of one's ancestors is called recapitulation. It is often expressed as "ontogeny recapitulates phylogeny"; that is, embryonic development (ontogeny) repeats phylogeny (the genealogy of the species).

This is a distortion of the truth. It implies, for example, that early in our embryonic development we go through a fishlike stage. We do not. Rather, we pass through some (not all) of the embryonic stages that our ancestors passed through. Therefore, we find that the more distantly related two vertebrates are, the shorter the period during which they pass through similar embryonic stages (fish and human) and vice versa (fish and salamander).

We should also keep in mind that embryonic development prior to the pharyngula (stage I) may also be very different in the different groups. For example, while the pharyngulas of the human and the salamander look quite similar, their earlier development, starting with their fertilized eggs, are very different [illustration].

The idea that "ontogeny recapitulates phylogeny" was proposed over a century ago by the biologist Ernst Haeckel. He also made the drawings on which the drawings above are based. Periodically, people rediscover that in making them, he altered certain details to emphasize his theory. Though they are schematic, the story they illustrate here has stood the test of time.

Protein Sequences

Protein sequencing provides a tool for establishing homologies from which genealogies can be constructed and phylogenetic trees drawn.

Here are two examples.

Hemoglobins

Human beta chain

0

Gorilla

1

Gibbon

2

Rhesus monkey

8

Dog

15

Horse, cow

25

Mouse

27

Gray kangaroo

38

Chicken

45

Frog

67

Lamprey

125

Sea slug (a mollusk)

127

Soybean (leghemoglobin)

124

An example of molecular homology.

The numbers represent the number of amino acid differences between the beta chain of humans and the hemoglobins of the other species. In general, the number is inversely proportional to the closeness of kinship.

All the values listed are for the beta chain except for the last three, in which the distinction between alpha and beta chains does not occur.

The human beta chain contains 146 amino acid residues, as do most of the others.


Cytochrome c

Cytochrome c is part of the respiratory chain down which electrons are passed to oxygen during cellular respiration. [Discussion]

Cytochrome c is found in the mitochondria of every aerobic eukaryote - animal, plant, and protist. The amino acid sequences of many of these have been determined, and comparing them shows that they are related.

Human cytochrome c contains 104 amino acids, and 37 of these have been found at equivalent positions in every cytochrome c that has been sequenced. We assume that each of these molecules has descended from a precursor cytochrome in a primitive microbe that existed over 2 billion years ago. In other words, these molecules are homologous.

The first step in comparing cytochrome c sequences is to align them to find the maximum number of positions that have the same amino acid. Sometimes gaps are introduced to maximize the number of identities in the alignment (none was needed in this table). Gaps correct for insertions and deletions that occurred during the evolution of the molecule.

This table shows the N-terminal 22 amino acid residues of human cytochrome c with the corresponding sequences from six other organisms aligned beneath. A dash indicates that the amino acid is the same one found at that position in the human molecule. All the vertebrate cytochromes (the first four) start with glycine (Gly). The Drosophila, wheat, and yeast cytochromes have several amino acids that precede the sequence shown here (indicated by <<<). In every case, the heme group of the cytochrome is attached to Cys-14. and Cys-17 (human numbering). In addition to the two Cys residues, Gly-1, Gly-6, Phe-10, and His-18 are found at the equivalent positions in every cytochrome c that has been sequenced.

Molecular homology of cytochrome c

 

 

1

 

 

 

 

6

 

 

 

10

 

 

 

14

 

 

17

18

 

20

 

 

Human

 

Gly

Asp

Val

Glu

Lys

Gly

Lys

Lys

Ile

Phe

Ile

Met

Lys

Cys

Ser

Gln

Cys

His

Thr

Val

Glu

Lys

Pig

 

-

-

-

-

-

-

-

-

-

-

Val

Gln

-

-

Ala

-

-

-

-

-

-

-

Chicken

 

-

-

Ile

-

-

-

-

-

-

-

Val

Gln

-

-

-

-

-

-

-

-

-

-

Dogfish

 

-

-

-

-

-

-

-

-

Val

-

Val

Gln

-

-

Ala

-

-

-

-

-

-

Asn

Drosophila

<<<

-

-

-

-

-

-

-

-

Leu

 

Val

Gln

Arg

 

Ala

-

-

-

-

-

-

Ala

Wheat

<<<

-

Asn

Pro

Asp

Ala

-

Ala

-

-

-

Lys

Thr

-

-

Ala

-

-

-

-

-

Asp

Ala

Yeast

<<<

-

Ser

Ala

Lys

-

-

Ala

Thr

Leu

-

Lys

Thr

Arg

-

Glu

Leu

-

-

-

-

-

-

We assume that the more identities there are between two molecules, the more recently they have evolved from a common ancestral molecule and thus the closer the kinship of their owners. Thus the cytochrome c of the rhesus monkey is identical to that of humans except for one amino acid, whereas yeast cytochrome c differs from that of humans at 44 positions. (There are no differences between the cytochrome c of humans and that of chimpanzees.)

Phylogenetic trees



With such information, one can reconstruct an evolutionary history of the molecule and thus of their respective owners. This requires

The result is a phylogenetic tree. This one (the work of Walter M. Fitch and Emanuel Margoliash) shows the relationship between 20 species of eukaryotes. The numbers represent the minimum number of nucleotide substitutions in the gene for cytochrome c needed to produce these 20 proteins from a series of hypothetical ancestral genes at the various branching points (nodes).

The tree corresponds quite well to what we have long believed to be the evolutionary relationships among the vertebrates. But there are some anomalies. It indicates, for example, that the primates (humans and monkeys) split off before the split separating the kangaroo, a marsupial, from the other placental mammals. This is certainly wrong. But sequence analysis of other proteins can resolve such discrepancies.

Cytochrome c is an ancient molecule, and it has evolved very slowly. Even after more than 2 billion years, one-third of its amino acids are unchanged. This conservatism is a great help in working out the evolutionary relationships between distantly-related creatures like fish and humans.

But what of humans and the great apes? Their cytochrome c molecules are identical and can tell us nothing about evolutionary relationships.

However, some proteins have evolved much more rapidly than cytochrome c, and these can be used to decipher recent evolutionary events. During blood clotting, short peptides are cut from fibrinogen converting it into insoluble fibrin. Once removed, these fibrinopeptides have no further function. They have been pretty much free from the rigors of natural selection and have, consequently, diverged rapidly during evolution. So they provide data useful in sorting out the twigs of phylogenetic trees of mammals, for example.

DNA-DNA Hybridization

As we saw in the comparison of human and kangaroo cytochrome c, a single molecule provides only a narrow window for glimpsing evolutionary relationships.

The technique of DNA-DNA hybridization provides a way of comparing the total genome of two species. Let us examine the procedure as it might be used to assess the evolutionary relationship of species B to species A:

As the figure shows, the curve for A/B is to the left of A/A, i.e., duplexes of A/B separated at a lower temperature than those of A/A. The sequences of A/A are precisely complementary so all the hydrogen bonds between complementary base pairs (A-T, C-G) must be broken in order to separate the strands. But where the gene sequences in B differ from those in A, no base pairing will have occurred and denaturation is easier.

Thus DNA-DNA hybridization provides genetic comparisons integrated over the entire genome. Its use has cleared up several puzzling taxonomic relationships.

Link to a phylogenetic tree of living hominoids based on DNA-DNA hybridization.

Chromosome Painting

Another way to compare entire genomes is to

The method is a modification of fluorescence in situ hybridization (FISH) and is also called Zoo-FISH.

Chromosome painting has shown, for example, that large sections of human chromosome 6 (which includes hundreds of genes in the major histocompatibility complex (MHC) have their counterpart; i.e. homologous genes, in

Comparing DNA Sequences

Proteins are the expression of genes so why not compare the actual gene sequences? There are several advantages:

 

 

 

 

 

 

 

 

Some of the most informative studies using comparative DNA sequencing have been done with

In both cases, the genes are present in multiple copies making their isolation easier.

Cladistics

Ideally, a system of classification should reflect the genealogies of the organisms. Darwin realized this when he wrote: "our classifications will come, as far as they can be so made, genealogies".

A classification based strictly on the rule that all members of a group must have shared a common ancestor more recently than they have with any species outside the group is called cladistics.

This phylogenetic tree or cladogram depicts the evolutionary relationships of 4 hypothetical species.

Taxonomists who use cladistic methods have created an extraordinary vocabulary to help them (not necessarily us).

o                                Ancestral traits are called plesiomorphic (shown here as black numbers).

o                                Derived traits are called apomorphic (shown here as colored numbers). All the members of a clade must share one or more apomorphic traits not found in any other species.

o                                Derived traits shared by two or more species are called synapomorphic. Here species A and B share the synapomorphic trait designated with a blue 3 .

o                                Ancestral traits shared by two or more species are called symplesiomorphic. Here, the trait shown as black 1 is a symplesiomorphic trait retained by all 4 species.

Even if we reconstruct a precise genealogy and draw a phylogenetic tree to represent it, taxonomic problems may still remain.

1.     The species is the only taxonomic category that exists in nature. All higher categories (e.g., genus, family, and order) are purely arbitrary. They are created by taxonomists. For example,

o        Should species C and D be placed in a single genus with A and B in another?

o        Or are all four sufficiently closely related that they belong in a single genus?

o        Or are all four so distantly related that they should be placed in separate genera?

o        Note that none of these options (and others besides) violates the fundamental rule that all the members of any one group (or "clade") must have had a common ancestor more recent than any they share with species in other groups.

o       

Those taxonomists who are particularly impressed by the differences between species tend to increase the number of higher categories. Those with this bias are known fondly as "splitters". "Lumpers", those taxonomists who marvel at the uniformities they see among species, tend to create fewer higher categories. Thus, splitters might put each of the 4 species in separate genera while lumpers would put them in a single genus.

2.     Classifications based strictly on cladistics are too complex for convenience. In principle, a separate category has to be created for all the branches derived from each node of the tree. The box shows the conventional classification of Homo sapiens (in the order Primates of the class Mammalia). Compare it with the graphic above the box showing a classification of just the primates based more closely on cladistics.

3.     A classification based strictly on evolutionary kinship (cladistics) also may often seem to violate common sense. Thus a phylogenetic tree showing the evolutionary history that gave rise to the salmon (a fish), the lungfish, and the cow requires - according to cladistics - that the lungfish and cow be placed in a clade separate from the salmon. Even though the lungfish is a fish, the cow has shared a common ancestor with it more recently than its common ancestor with the salmon. Although it is traditional to classify the lungfish and the salmon together in the class Pisces (fishes), and to assign the cow to the class Mammalia, this violates the rule of cladistics. The lungfish and the cow with their apomorphic traits of

o        internal nostrils and

o        epiglottis

are descended from a common ancestor (red arrow) that is also the ancestor of all land-living vertebrates (including ourselves!).

Even Darwin recognized that kinship alone was not always enough for a sound taxonomy so he added a second criterion - degree of similarity - to be used in assigning species to a taxonomic category.

Other Problems to Drawing Phylogenetic Trees

1.     Deducing the evolutionary history of animals is particularly difficult because all the 24 or more phyla of animals appeared within a short time before and during the Cambrian and have since evolved along separate lines. This means that all the branches on the phylogenetic tree are long and bunched so closely at their base that it is difficult to determine their relationships. More data would help, but

2.     Computer power. As more data become available, the ability of computer programs to sort out the most likely tree becomes overwhelmed.

3.     Changing rate of evolution. There is considerable evidence that mutation rates are not steady from branch to branch in phylogenetic trees. Thus a branch based on molecules that have evolved rapidly would seem longer than otherwise.

4.     Back mutations. These mask the changes that preceded them and make branches look shorter than they should be.

5.     Gene transfer between species. The recent availability of complete gene sequences for many bacteria have revealed genes that appear to have passed from one group to another rather than having been descended from a common ancestor. Most of these "horizontal" transfers are between two different species of bacteria, but the gene sequence of Mycobacterium tuberculosis reveals 8 genes that it appears to have picked up from its human host! So many of these have appeared that some microbial taxonomists despair that a proper phylogenetic tree can ever be deduced for them.

Link to a tabulation of the various bacteria and archaea whose complete gene sequences are now known.

6.     Convergent evolution.Evolution in which two species from different genealogies come to resemble each other is called convergent evolution and structures that resemble each other superficially (and may serve the same function) are called analogous.

There are many examples of marsupial mammals in Australia which bear a striking resemblance to placental mammals of Europe and North America. The North American woodchuck or groundhog and the Australian wombat (photo courtesy of the Australian News and Information Bureau), for examples, look superficially to be close relatives. But their similarities are analogous, not homologous, and have arisen as a result of similar selection pressures in similar ecological niches. The wombat has no placenta, cares for its young in a pouch as other marsupials do, and should be classified with them. In fact we are more closely related to the North American woodchuck than the wombat is!

In the language of cladistics, the wombat is placed in a clade with all marsupials because they share the marsupial pouch (an apomorphic trait) but are nonetheless mammals because they, too, have hair (a plesiomorphic trait).

Convergent evolution also occurs at the level of molecules.

Examples:

o        Cows and langur monkeys both synthesize a lysozyme that share the same activity, but comparison of their amino acid sequences indicates that each has evolved from a different ancestral molecule.

o        Cows and the bacterium Yersinia both synthesize a tyrosine phosphatase with similar three-dimensional structures around their active site and similar activity. However, each has evolved from a totally different ancestral molecule.

o        The bacterium Bacillus subtilis synthesizes a serine protease that acts just like those synthesized by mammals but not only has an entirely different primary structure but its three-dimensional structure (tertiary) structure is different as well.

 

Characteristics of Birds Lab

The place in which a bird lives supplies the animal with food. Using each of the birds mentioned, determine, as closely as possible, the type of area in which they live. List these habitats ( places where they live ) in the table at the end of the lab marked Habitat.
Answer the following questions completely based on what you know about birds.
1. What are some of the foods the birds in the pictures might eat?
2. Birds living near lakes, pond or the ocean are most likely to eat the following organisms.
3. If you see birds walking around a lawn in front of your house, what types of things could serve as a food supply for these birds?
4. Explain why dead or diseased trees can serve as a food source for some birds.
Part 2
The beaks of birds have their job or function based on their shape. Look at the pictures of the bird ( Click Here ). Examine the beak of each bird and determine the type of each beak based on its shape and function. Some beak types may be used more than once. Place your choices on the chart in the column marked Beak for:
Beak types:
a). cracking type --- eats small seeds.
b). spear shape --- spearing fish
c). chisel shape --- drilling for insects
d). hooked --- catch prey
e). tubular --- to suck nectar
f). long and stout --- to scoop fish
g). short multipurpose --- can do many things.
h). crossed --- for chopping nuts.
Foot Adaptations:
Examine the pictures of each bird and determine the type of feet each bird contains. Place the name of the bird on the line that best describes their type of feet.

Also place the foot type on the chart in column 3 titled Feet for. Some foot types may contain more than one bird. a). 2 toes in front and 2 behind used for climbing.
b). 3 toes in front and 1 behind, long and used to walk in water.
c). 3 toes in front and 1 in back, used for swimming
d). 3 toes in front and 1 in back, contains long claws (talons).
e). 3 in front and 1 in back, used to sit on a branch.
f). 3 in front and 1 in the back, for walking on water.
g). 2 toes in the front, for running.
Summary:
1. Based on the talons found on an eagle, what type of beak would it contain?
2. A falcon looks like it has perching feet. What type of claws does it contain based on the hooked beak?
3. Which bird contain the longest legs? What type of food do you think it eats?
4. If you found a bird with climbing feet, what type of food would you expect it to eat?
5. How many of the birds live near water? How can we tell?

Chart of Characteristics

Name of Bird

Habitat

Beak for

Feet for

Woodpecker

 

 

 

Quail

 

 

 

Pelican

 

 

 

Eagle

 

 

 

Falcon

 

 

 

Robin

 

 

 

Ostrich

 

 

 

Hummingbird

 

 

 

Heron

 

 

 

Whippoorwill

 

 

 

Jacana

 

 

 

Crossbill

 

 

 

 

The history of life as revealed by the fossil record.  http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/G/GeoEras.html

 

Eras

Periods

Epochs

Aquatic Life

Terrestrial Life

With approximate starting dates in millions of years ago in parentheses. Geologic features in green

Cenozoic (65)
The "Age of Mammals"

 

 

 

 

Quaternary (1.8)

Recent

 

Humans in the new world

Pleistocene

Periodic glaciation

First humans

Continental drift continues

Tertiary (65)

Pliocene

All modern groups present

Hominids and pongids

Miocene

Monkeys and ancestors of apes

Oligocene

Adaptive radiation of birds

Eocene

Adaptive radiation of mammals

Paleocene

 

Mesozoic (250)
"The Age of Reptiles"

Cretaceous (145)

Still attached: N. America & N. Europe; Australia & Antarctica

 

 

 

Modern bony fishes

Extinction of dinosaurs, pterosaurs

 

 

 

Extinction of ammonites, plesiosaurs, ichthyosaurs

Rise of woody angiosperms, snakes; first placental mammals (Eutheria)

 

 

Africa & S. America begin to drift apart

 

 

Jurassic (205)

 

Plesiosaurs, ichthyosaurs abundant

Dinosaurs dominant; first angiosperms

 

 

 

Ammonites again abundant

First mammals; Archaeopteryx; first lizards

 

 

 

Skates, rays, and bony fishes abundant

Adaptive radiation of dinosaurs; insects abundant

 

 

 

 

 

 

 

 

Pangaea splits into Laurasia and Gondwana

 

 

Triassic (250)

 

First plesiosaurs, ichthyosaurs

Adaptive radiation of reptiles:
thecodonts, therapsids, turtles,
crocodiles, first dinosaurs

 

 

 

Ammonites abundant at first

 

 

 

Rise of bony fishes

 

 

Paleozoic (543)

Permian (286)

Appalachian Mts. formed; periodic glaciation and arid climate

 

 

 

Extinction of trilobites, placoderms

Reptiles abundant: cotylosaurs, pelycosaurs. Cycads, conifers, ginkgos

 

 

Pennsylvanian (320)

Warm, humid climate Together
the Pennsylvanian and Mississippian
make up the
"Carboniferous";
also called the
"Age of Amphibians"

 

 

 

 

Ammonites, bony fishes

First reptiles
Coal swamps

 

 

 

 

 

 

 

Mississippian (360)

Adaptive radiation of sharks

Forests of lycopsids, sphenopsids, and seed ferns
Amphibians abundant
Land snails

 

 

 

Periodic aridity

 

 

 

 

Devonian (408)
The "Age of Fishes"

 

Placoderms, cartilaginous and bony fishes. Ammonites, nautiloids

Ferns, lycopsids, and sphenopsids
First gymnosperms
First insects
First amphibians

 

 

Extensive inland seas

 

 

 

 

 

Adaptive radiation of ostracoderms, eurypterids

Arachnids (scorpions)

 

 

Silurian (438)

Mild climate; inland seas

Nautiloids, Pilina, other mollusks

 

 

 

Ordovician (490)

Mild climate, inland seas

Trilobites abundant
First jawless vertebrates
Trilobites dominant

First fungi and bryophytes
First millipedes?

 

 

Cambrian (543)

 

First eurypterids, crustaceans
Mollusks, echinoderms
Sponges, cnidarians, annelids
Tunicates

No fossils of eukaryotes, but phylogenetic trees suggest that lichens, mosses, perhaps even vascular plants were present.

 

 

Periodic glaciation

 

 

Proterozoic (2500)
Archean (4500)

 

 

Fossils rare but many protistan and invertebrate phyla toward the end

No fossils of eukaryotes, but phylogenetic trees suggest that lichens, mosses, perhaps even vascular plants were present towards the end.

 

 

The Geologic and Evolutionary Record

A remarkable feature of the table above is how often evolutionary changes coincided with geologic changes on the earth. But consider that changes in geology (e.g., mountain formation or lowering of the sea level) cause changes in climate, and together these alter the habitats available for life. Two types of geologic change seem to have had especially dramatic effects on life:

Continental Drift

A body of evidence, both geological and biological, supports the conclusion that 200 million years ago, at the start of the Mesozoic era, all the continents were attached to one another in a single land mass, which has been named Pangaea.

This drawing of Pangaea (adapted from data of R. S. Dietz and J. C. Holden) is based on a computer-generated fit of the continents as they would look if the sea level were lowered by 6000 feet.

During the Triassic, Pangaea began to break up, first into two major land masses:

The present continents separated at intervals throughout the remainder of the Mesozoic and through the Cenozoic, eventually reaching the positions they have today.

Let us examine some of the evidence.

Shape of the Continents

The east coast of South America and the west coast of Africa and are strikingly complementary. This is even more dramatic when one tries to fit the continents together using the boundaries of the continental slopes (e.g., 6000 feet down) rather than the shorelines.

Geology

Fossils

The Impact Hypothesis

The Cretaceous period, the last period of the Mesozoic, marked the end of the Age of Reptiles. It was followed by the Cenozoic era, the Age of Mammals. Although extinctions have occurred throughout the history of life, an extraordinary number of them occurred in a relatively brief period at the end of the Cretaceous. Why?

The Alvarez Theory

Louis Alvarez, his son Walter, and their colleagues proposed that a giant asteroid or comet striking the earth some 65 million years ago caused the massive die-off at the end of the Cretaceous. Presumably, the impact generated so much dust and gases that skies were darkened all over the earth, photosynthesis declined, and worldwide temperatures dropped. The outcome was that as many as 75% of all species - including all dinosaurs - became extinct.

The key piece of evidence for the Alvarez hypothesis was the finding of thin deposits of clay containing the element iridium at the interface between the rocks of the Cretaceous and those of the Tertiary period (called the K-T boundary after the German word for Cretaceous). Iridium is a rare element on earth (although often discharged from volcanos), but occurs in certain meteorites at concentrations thousands of times greater than in the earth's crust.

After languishing for many years, the Alvarez theory gained strong support from the discovery in the 90s of the remains of a huge (180 km in diameter) crater in the Yucatan Peninsula that dated to 65 million years ago.

The abundance of sulfate-containing rock in the region suggests that the impact generated enormous amounts of sulfur dioxide (SO2), which later returned to earth as a bath of acid rain.

A smaller crater in Iowa, formed at the same time, many have contributed to the devastation. Perhaps during this period the earth passed through a swarm of asteroids or a comet and the repeated impacts made the earth uninhabitable for so many creatures of the Mesozoic.

An Impact at the End of the Triassic?

A mass-extinction of non-dinosaur reptiles occurred earlier, at the end of the Triassic. It was followed by a great expansion in the diversity of dinosaurs. The recent discovery of a layer enriched in iridium in rocks formed at the boundary between the Triassic and Jurassic suggests that impact from an asteroid or comet may have been responsible then just as it was at the K-T boundary.

  

http://www.geo.ucalgary.ca/~macrae/Burgess_Shale/


 

Burgess Shale fossils

The Burgess Shale is an exceptional Middle Cambrian age (about 540 million years ago) fossil locality located in Yoho National Park in the Rocky Mountains, near Field, British Columbia, Canada. The locality is special because of the soft-bodied preservation of a wide diversity of fossil invertebrate animals. The locality has been intensely studied since its discovery in 1909 by Charles Walcott, and has been declared a World Heritage Site. A popular introduction to the Burgess Shale can be found in Steven J. Gould's book, "Wonderful Life".

The Burgess Shale occurs within the Stephen Formation in Burgess Pass on the southwest side of the saddle between Mount Wapta and Mount Field. At the time of deposition, this area was near the equator, and was the continental margin of North America. A 100m high near-vertical cliff of limestone occurred at the edge of the shelf. These rocks are known as the Cathedral Formation, and probably represent the escarpment of a large submarine slump (i.e. landslide) like those observed off the edge of carbonate platforms in areas like the Bahamas and Honduras today. The Burgess Shale was deposited at the base of this cliff, probably in anoxic conditions, as indicated by the lack of bioturbation (burrows, trackways, etc.) and the abundance of pyrite (often indicating the presence of H2S). All the organisms within the Burgess Shale have been transported to this location, probably by small mudflows that flowed over the edge of the cliff. This accounts for the variable orientation of the fossils and their superb preservation.

There are two quarries on Mt. Field/Mt. Wapta -- the lower Walcott Quarry and the upper Raymond Quarry, the latter a few metres stratigraphically higher in the Stephen Formation. The faunas in the two quarries are similar, but with differences in the relative abundance of some of the organisms. Additional localities with soft-bodied preservation, and further differences in the fauna have been found on Mt. Stephen and further south.

The illustrations presented here are from photographs taken in the Walcott and Raymond quarries on September 24, 1995 during a hike guided by Glen DePaoli of the Yoho-Burgess Shale Research Foundation. No collecting is permitted in the quarries (or anywhere in Yoho National Park), and all trips to the quarry must be guided. See Burgess Shale hike information for details. Although collecting is not an option, there is plenty of material visible in the quarries, so a macro lens offers the ability to bring back plenty of photographs. It would not take much to do better than my results (I do not have great equipment and I did not even use a tripod). If you try this yourself, you may want to experiment with wetting the specimens or orienting them to reflect the sunlight.

These pictures are copyright (c) 1995 by Andrew MacRae, but are freely distributable for non-commercial use, provided you give credit. Please contact me for other arrangements. I have 24-bit versions of these images, if anyone wants higher quality.

The Walcott Quarry

Looking northwest -- 328Kbytes. Mount Wapta is the peak visible in the distance. The escarpment in the Cathedral Formation is visible just a few metres beyond the edge of the quarry on the left. It occurs at the contact between the white dolomite and the grey slate/shale of the Stephen Formation. If you have access to older photographs of the Walcott quarry, it is worth comparing them to this photo -- the quarry has doubled in size as a result of continued work in the last few years, mainly by Des Collins at the Royal Ontario Museum.

Bedding in the Walcott quarry -- 144Kbytes. This photo shows details of the bedding within the Burgess Shale. The bedding occurs a the scale of a few centimetres, and consists mostly of graded beds. The yellowish bands are slightly calcareous, while the darker grey bands are more pelitic (clayey). Both lithologies are very fine grained (silt size grains or smaller). These lithological differences are obvious only where the weathering of the face of the quarry has altered the carbonate-rich beds. The graded beds represent individual sediment-input events, possibly representing storms that disturbed muddy sediment high on the escarpment, and caused it to rain down into the deeper water at this location, burying and smothering organisms carried along for the ride. The scale bar is 30 centimetres.

Anomalocaris sp.

Anomalocaris frontal appendage/claw -- 152Kbytes. This specimen is only a small part of Anomalocaris, which was a large (up to 60cm or more) arthropod-like predator. This claw was used to grasp prey. Walcott quarry.

Marrella

Marrella splendens is a small "arthropod" somewhat reminiscent of a trilobite, but with several distinctive features. This illustration also shows the dark "blob" produced by body contents which were squeezed out of the animal after burial. Marrella is one of the most common fossils in the Burgess Shale, and was probably the first soft-bodied organism noticed by Walcott. Walcott quarry.

Marrella splendens. The Burgess Shale fossils are preserved as highly-compressed films on the surface of the rock, with some 3-dimensional structure preserved. Some organic material is preserved on the surface, and this produces a highly reflective surface. This Marrella example uses reflected light, making the fossil look light-coloured against the dark shale/slate background. Contrast this appearance with the previous example, which uses diffuse light. Walcott quarry.

Trilobites

Olenoides serratus. This is the largest of several species of trilobites found in the Burgess Shale, some of which have been preserved with soft appendages. This specimen is missing its left free cheek (on the head), but its skeleton is otherwise complete, and I think one of the posterior antennae is present, but it is not easily visible in the photograph. The orange colour is produced by iron oxides. This specimen was wetted for the photograph. Walcott quarry.

Agnostid trilobites are also common in the quarry, but none appear to have appendages preserved.

Sponges

Vauxia gracilenta has a branching morphology, and is very common. Walcott quarry.

Tuzoia

Tuzoia is a "bivalved" crustacean grossly similar to certain types of modern brine shrimp. This photo shows only the carapace (the two shells), with their distinctive reticulate surface ornamentation. In early interpretations, the claw of Anomalocaris was reconstructed as the tail of Tuzoia! Tuzoia is particulary common in the Raymond quarry, where this photo was taken.

Ottoia and Leanchoilia

Ottoia, showing muscle bands and gut. Ottoia is a priapulid worm found commonly in the Burgess Shale. It was carnivorous, and probably lived in a burrow like modern priapulids. This specimen has been wetted and oriented to reflect the light, in order to show a delicate irridescent film which preserves details of muscle bands, the gut, and even the small hooks at one end of the worm (on the right -- unfortunately out of focus). Walcott quarry.

Ottoia and Leanchoilia -- 424Kbytes. This specimen has two individuals of Ottoia and portions of at least three individuals of Leanchoilia. The specimen on the right has just the head, and shows the pair of peculiar appendages found on Leanchoilia. The specimen on the left (with swimming appendages directed upwards -- I am not sure if this is upside-down or not :-)) is particularly interesting -- it has some dark-coloured sand-size (shell?) fragments in a linear arrangement along the back of the animal. I think these are gut contents. Cool! This specimen is from the Raymond quarry, where Leanchoilia is particularly common.

 

Plants

Index to this page

Evolution and Classification

The organisms we call plants are assigned to a single clade; that is, a natural grouping based on the belief that they have all evolved from a common ancestor more recent than any shared with other organisms.

Among the criteria for doing this are:

Green algae (Division Chlorophyta)

The ancestors of these organisms were the most primitive members of the clade. In other words, organisms that we would put in this division were probably the ancestors of all the other plants.

There are some 7000 species living today. They include:

Although some of the multicellular forms are large, they never develop more than a few differentiated types of cells and their fertilized eggs do not develop into an embryo.

Green algae are an important source of food for many aquatic animals. When lakes and ponds are "fertilized" with phosphates and nitrates (e.g., from sewage and the runoff from fertilized fields and lawns), green algae often form extensive algal "blooms".

Liverworts and Mosses

These are fairly simple plants that do produce a number of differentiated cell types and whose fertilized egg develops into a distinct embryo.

However, they have neither

and thus never grow very large.

Some 16,000 living species are known. Most grow in moist places.

Link to an illustrated discussion of mosses.

Lycopsids (Division Lycopsida)

The members of this group are often called club mosses. They are not mosses at all, but vascular plants with xylem and phloem running through their roots, stems, and leaves. The leaves are quite simple and small with their vascular tissue in a single, unbranched vein.

The "club" of their name comes from the appearance of their spore-forming structures called strobili.

Club mosses are also sometimes called "ground pines", but they are not pines either. The photo shows Lycopodium obscurum.

About 1000 species of lycopsids exist today. All are small (those in the photo stand about 8 in. [20 cm] tall), but it was not always so. Fossil lycopsids in the Mississippian and Pennsylvanian periods (the so-called Carboniferous era) reached heights of 100 feet. Their remains contributed to the formation of coal.


Chloroplast Genes

Chloroplasts (as well as mitochondria) have their own genome.

Link to discussion of the reason for this.

The diagram (based on the work of Ohyama, K. et al., Nature 322:572, 1986 and Linda A. Raubeson and R. K. Jansen, Science 225:1697, 1992) shows the genome of the first chloroplast DNA to be sequenced, that of the liverwort Marchantia polymorpha. It contains 121,024 base pairs encoding 128 genes. The short lines indicate a few of the tRNA genes, some of which are labeled.

The order of the genes between the arrows (~6:30 to ~10:00) is also found in the lycopsids. But in all other vascular plants, this region is inverted and the order of the genes is precisely reversed. This provides further evidence that the other vascular plants we shall examine below, the

belong to a separate clade.

Horsetails (Division Sphenopsida)

The common name comes from the characteristic pattern of branching: whorls or rings of branchlets arising from an aboveground shoot. The shoot develops each season from an underground stem (rhizome).

Horsetails often grow in sandy places and incorporate silica in their stems. This gives them an abrasive quality which caused them to once be used for cleaning pots and pans, which gave rise to another common name: scouring rush.

Only one genus of sphenopsids, Equisetum, containing about 25 species, survives today (it is placed in the division Equisetopsida). However, many other, much larger, species were dominant features of the Carboniferous and, like the early lycopsids, contributed to the formation of coal.

Ferns (Division Filicopsida)

Approximately 9500 species of ferns live on earth today. Many of these are found in the tropics where some - the "tree ferns" - may grow to heights of 40 ft (13 m) or more. The ferns of temperate regions are smaller. They are usually found in damp, shady locations. Their stems - called rhizomes - as well as their roots grow underground and are perennial. Their leaves, called fronds, grow up from the rhizome each spring.

Link to an illustrated discussion of ferns.

Gymnosperms

Fossil from the Devonian period reveal fernlike plants that were heterosporus; that is, produced two kinds of spores.

The megaspores were not released from the parent sporophyte. Fertilization took place within the tissue of the parent sporophyte thus freed from dependence on surface water.

However, the necessity for the microspores to be carried from one plant to another in order to reach the female gametophyte robbed them of their value as agents of dispersal. This function was taken over by seeds - dormant, protected, embryo sporophytes.

 

 

 

 

 

 

 

 

 

 

 

 

The seed ferns, as these plants are called, were among the earliest gymnosperms. Although seed ferns are now extinct, some of their living descendants, the cycads, resemble them closely. Cycads reveal their ancient lineage by the fact that after the microspore reaches the ovule, it liberates a ciliated sperm which, swimming in moisture supplied by the parent sporophyte, reaches the egg.

Ginkgos are another group of gymnosperms that use motile sperm.

Conifers

Conifers get their name from the cones in which the both microspores and megaspores develop.

The male cones produce microspores that develop into pollen grains that are carried by the wind to the female cones. Here each germinates into a pollen tube which grows into the tissues of the female cone until it reaches the vicinity of the egg. (In pines, this may take a year.) Then the tube ruptures and a sperm nucleus fuses with the egg to form the zygote.

After fertilization, the zygote develops into a tiny embryo sporophyte plant.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There are approximately 550 species of living conifers. They include the

Conifers include the largest and the oldest of all living organisms. One redwood (genus Sequoia) growing in California is almost 400 feet high. Bristlecone pines growing in the mountains of eastern California are more than 4000 years old.

Although most conifers are evergreen, their leaves are modified as "needles", and these reduce snow load and transpiration during the winter in the harsh high-latitude climates where conifers are the dominant species of plants. But by retaining their needles during the winter, conifers are ready to begin photosynthesis immediately upon the return of spring.

Coniferous forests are of great economic importance producing lumber for building and pulp for paper making.

Angiosperms

Although angiosperms appear in the fossil record in Jurassic deposits, it was not until the end of the Mesozoic era that angiosperms became the dominant plants of the landscape. That they dominate the earth's flora today is clear: there are some 240,000 species of living angiosperms; the rest of the plant kingdom includes only some 34,000 species.

Dicots and Monocots

Angiosperms fall into more than a dozen clades, all but one of which are commonly called dicots because their seeds have two cotyledons.

Dicot traits:

Monocot traits:

The monocots belong to a single clade and share these traits:

Monocots include:

Alternation of Generations

Sexual reproduction involves the two alternating processes of meiosis and fertilization.

Whatever variation in details there may be from one organism to another, these two activities must occur alternately if sexual reproduction is to continue.

In animals, meiosis generates the haploid gametes - sperm and eggs - directly. These single cells fuse to form the zygote which will develop into another diploid animal.

In most plants meiosis and fertilization divide the life of the organism into two distinct phases or "generations".

Two points revealed by plant life cycles:

In fact, the gametophyte generation is the major stage in the life of mosses and an independent plant in ferns.

Links to descriptions of the gametophytes of mosses and of ferns.

However, the gametophyte is only an inconspicuous structure in angiosperms and other "higher" plants.

 

Sexual Reproduction in Angiosperms

Index to this page

Angiosperms are the flowering plants (today the most abundant and diverse plants on earth).

Most are terrestrial and all lack locomotion. This poses several problems.

The functions of the flower solve both of these problems.

The Flower and Its Pollination

In angiosperms, meiosis in the sporophyte generation produces two kinds of spores.

Link to a discussion of the alternation of gametophyte and sporophyte generations

 

Both types of sporangia are formed in flowers.

In most angiosperms, the flowers are perfect: each has both microsporangia and megasporangia.

Some angiosperms are imperfect, having either microsporangia or megasporangia but not both.

Flowers develop from flower buds. Each bud contains 4 concentric whorls of tissue. From the outer to the inner, these develop into

Link to a discussion of the genetic control of flower formation.

 

Stamens

Each stamen consists of a

Meiosis of the diploid microspore mother cells in the anther produces four haploid microspores. Each of these develops into a two-celled pollen grain.

The two cells are the

Carpels

Carpels consist of a

Often the entire whorl of carpels is fused into a single pistil.

The megasporangia, called ovules, develop within the ovary.

Meiosis of the megaspore mother cell in each ovule produces 4 haploid cells:

Development of the megaspore

Link to a view of the entire process. Warnings: a large file (125K); you will have to scroll through it; looks best on a light browser background.

The nucleus of the megaspore undergoes 3 successive mitotic divisions. The 8 nuclei that result are distributed and partitioned off by cell walls to form the embryo sac. This is the mature female gametophyte generation.

Pollination

When a pollen grain reaches the stigma, it germinates into a pollen tube. The generative nucleus divides by mitosis forming 2 sperm nuclei. These, along with the tube nucleus, migrate down the pollen tube as it grows through the style and into the ovule chamber.

The pollen tube with its contents makes up the mature male gametophyte generation.

Double fertilization

The pollen tube enters the ovule through the micropyle and ruptures.

Self-incompatibility

Most angiosperms have mechanisms by which they avoid self-fertilization. Link to a discussion of these.

Seeds

After double fertilization, each ovule develops into a seed, which consists of

The food in the cotyledons is derived from the endosperm which, in turn, received it from the parent sporophyte. In many angiosperms (e.g., beans), when the seeds are mature, the endosperm has been totally consumed and its food transferred to the cotyledons. In others (some dicots and all monocots), the endosperm persists in the mature seed.

The seed is thus a dormant embryo sporophyte with stored food and protective coats. Its two functions are


Fruits

Fruits are a development of the ovary wall and sometimes other flower parts as well. As seeds mature, they release the hormone auxin, which stimulates the wall of the ovary to develop into the fruit. In fact, commercial fruit growers may stimulate fruit development in nonpollinated flowers by applying synthetic auxin to the flower.

Fruits promote the dispersal of their content of seeds in a variety of ways.

 

  

 


Photosynthesis Review


 


1. light wavelengths:


            a. which are used by PS


            b. relative energy values of different colors


            c. absorption spectra of chlorophyll


            d. which color(s) is(are) reflected by green leaves


2. Chloroplast structure


            a. thylakoid


            b. stroma


3. The events in the light reactions, in chronological order


4. Water vapor from the air is split into H and O during Light reactions


5. Englemann's experiment


6. H2O is the source of hydrogen for the Calvin cycle


7. Resonant frequencies of the reaction centres in PS II and PSI


8. The chemioosmotic process which results in the synthesis of ATP


            a. the source of energy to move protons


            b. where the proton gradient is


            c. where the ATP is synthesized


9. The differences between cyclic and noncyclic photophosphorylation


10. The reactant molecules needed for the Calvin cycle


11.  The structure of the C3 and C4 leaves


            a. stomata


            b. function of bundle sheath cells in C3 and C4


12. The C4 pathway


13. The enzymes of the C3 and C4 pathways


14. The output of the Calvin Cycle is glyceraldehyde phosphate; this can be converted into fructose, dextrose, etc.

 

Photosynthesis- 2 steps

1- Light Reaction "PHOTOLYSIS"

 

 

 

2- Dark Reaction: Carbon Fixation
Hydrogen (from Step 1) combines with CO2 to form the 3 carbon compound PGAL
2 PGAL compounds will combine.This forms Glucose: C6H12O6

 

Most photosynthesis occurs in the palisades mesophyll of the leaf where most chloroplasts are located.

CHLOROPLAST..USED FOR PHOTOSYNTHESIS IN EUKARYOTIC CELLS


Go here for lists of endangered species

 


Open Ended Question
PHOTOSYNTHESIS IMAGINE YOU ARE A CARBON ATOM. DESCRIBE YOUR TRIP FROM THE AIR INTO A DANDELION PLANT. THEN INTO A RABBIT THAT EATS THE DANDELION. THEN IS RETURNED BACK TO THE AIR.
WHY IS IT needed TO INCLUDE PLANTS ON A SPACE STATION ?



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©1998 Troy High School: Biology

  

 

MNEMONIC PAGE TAXONOMY

KEEP___________ KINGDOM
POND___________ PHYLUM
CLEAN___________CLASS
OR___________ ORDER
FISH___________ FAMILY
GET ___________GENUS
SICK___________SPECIES

THE 5 KINGDOMS  6 NOW!!!!

MY___________ MONERA
A            ?………Archeabacteria
PUPPY___________PROTISTA
FEELS___________FUNGI
PRETTY___________PLANT
AWESOME___________ANIMAL


ORGANIC CHEMISTRY KEY

CHO FOR ALL....CHON FOR PROTEIN...2:1 RATIO OF H to O in CARBOS

ORGANIC MIND SAVER
1 a) Contains CHO go to 2
b) Does not contain CHO.............INORGANIC

2 a) Contains CHON....PROTEIN
b) Doesn't contain CHON go to 3

3 a) Has a 2:1 ratio of H to O...CARBOHYDRATE
b) Has no 2:1 ratio of H to O ... LIPID
ENZYMES MOST END IN "ASE" Organic catalysts that act like a minister , priest or justice of the peace at a wedding. Substrates are like the bride and groom... they change after the wedding... the enzyme doesn't change... Vitamins act as coenzymes...helpers for enzymes... Fat Soluble ones KADE are toxic at high levels

CELL STUFF
All living cells come from other cells...
CELLS...the structural and functional unit of LIFE..

Plants have cell walls, large vacuoles and chlororplasts...
Go here for substructures of cells

Animals have centrioles and small vacuoles....

THE VIRUS IS THE EXCEPTION TO THE CELL THEORY

The Cell membrane or Plasma membrane is the selectively permeable "BOUNCER" of the cell.

SCHWANN all animals are made of cells (Swan is an animal)
SCHLIEDEN all plants are made of cells (Schlipin' anda Schlidin' on a banana peel..plants)

LIFE FUNCTIONS
3 R's GENTS
Respiration, Regulation, Reproduction...Growth, Excretion, Nutrition, Transport, Synthesis

CELLULAR RESPIRATION
You down with ATP ????... AERO oxygen........ ANER NO oxygen
Aerobic phase occurs in the MITOCHONDRIA... "The Powerhouse"

NUTRITION
HUMAN CHEMICAL DIGESTION BEGINS:
CARBOS in the mouth with salivary amylase
PROTEIN in the stomach with gastric protease
LIPIDS in the small intestine with lipase
ALL DIGESTION IS COMPLETED IN THE SMALL INTESTINE
The large intestine simply absorbs water

REGULATION

Reflex Arc:
R S I M E
Receptor...Sensory Neuron...Interneuron...Motor Neuron...Efffector (muscle or gland)

D C A T S
Neuron:
Dendrite...Cyton...Axon...Terminal Branch...Synapse (space between)
TRANSPORT
Solutions are made of solutes and solvents
S U GAR is a SOL U TE
COFFEE is a SOLVENT
Arteries carry blood AWAY from the heart
Veins carry blood TOWARD the heart
Atrium ^ top chambers of the heart
Ventricle bottom chambers of the heart

The Grassh_o_pper has an Open circulatory system

Plants

XY goes high....
PHLO goes low...it's organic

PHOTOSYNTHESIS

Photolysis = light cuts water
Oxygen released in light reaction comes from water
Dark reaction = synthesis of glucose from CO 2 and hydrogen
PGAL is a 3 carbon intermediate
I get sad (blue) at stop signs (red)
Plants hate green light

LOCOMOTION

Ligament is a bone to bone connection (BLB)
Tendon is a muscle to bone connection (MTB)

EXCRETION

Diffusion across a thin moist membrane

ECOLOGY

Producers make food

Consumers eat food

Biomass and energy are highest at the bottom of the pyramid

Humans have had both positive and negative affects upon the environment