Define science. 

objective problem solving method that involves a standard set of procedures.

Explain what science can and cannot be used for. 

Scientific inquiry can be used to study phenomena that can be observed and measured. It cannot be used to study things that cannot be observed or measured objectively. The word objective means "not influenced by personal feelings or opinions".  That means that scientists have to eliminate personal 

bias if they want their research to be valid. 

List the main steps in the scientific process. 

1) Make observation 

2) Come up with possible explanation (hypothesis) 

3) Make predictions based on hypothesis 

4) Test predictions 

5) Decide if results of test allow you to eliminate (reject) the hypothesis 

 Explain why science can be called a process of elimination. 

scientists eliminate the explanations that they can show are not valid and keep the others open for further consideration.  In fact they try to eliminate all of the hypotheses they have considered, even if they are left with none remaining.

What do we have to do before rejecting a hypothesis? 

it has to be tested. In order to test a hypothesis, we have to 

predict what will happen under the various conditions we are considering. If we didn't do this, we could be compromising our objectivity by allowing our perceptions to influence the results. 

 Explain how predictions are formulated from hypotheses using the if...then... process. 

can be made from hypotheses using deductive reasoning to formulate an "if...then" statement: "If (fill in hypothesis) is correct, then when we do this 

test we should see these results. For example, "If the battery is dead, then the car lights won't work." 

Describe the requirements for a controlled experiment. 

Test that can be accurately repeated. Only look at one variable. The rest are kept the same.

In an experiment, what is assumed to cause changes in the dependent variable? 

Explain why controls are necessary. 

What is done with the data at the end of the experiment?   

data from the experimental and control groups are 

compared. If there is no significant difference, then we can probably conclude that the independent variable had no effect on the dependent variable and we should reject any hypothesis that says it did. On the other hand, if there is a significant difference, we can say only that the difference between the two groups may be caused by the independent 

variable and we cannot reject the hypothesis at this time. 

How do scientists decide if the results of their experiments are valid? 

What is a scientific theory and what is its value? 

The study of the history of evolution focuses on: 

observing and interpreting the various kinds of remains (fossils) of things that lived long ago.  

The study of the process of evolution focuses on:  

all of the mechanisms that affect how living things 

have changed over time (genetic variation, natural selection, etc.). 

Why is studying the process of evolution important to us? 

so that we can understand how pathogens and parasites are able 

to survive the chemicals we have been using to kill them. 

 What can evolutionary biologists use fossils for? 

 to construct and test hypotheses and to better understand the 

process of evolution.  

Define fossil. 

any evidence of past life, including chemical evidence, body parts, traces or impressions of an animal or plant that has been preserved.

What materials can preserve fossils? 

burial in mud, quicksand, asphalt, volcanic ash, sandstorms or blizzards, lava flows, or water-borne sediments. Remains are also preserved in amber, permafrost, dry caverns, arid regions, and peat bogs.  

Have all organisms that ever lived become fossils?   Do fossilized organisms 

represent all types of organisms that ever lived?  Have scientists found examples of all fossilized organisms yet? 

Very few of the organisms that ever 

lived became fossils. Those organisms that were fossilized do not necessarily 

represent all types of organisms that ever existed. Even fewer fossils have yet been found by scientists who can identify them and their history. 

  Describe the sources of bias in the fossil evidence. 

most land-dwelling organisms, after they die, are rapidly devoured and 

decomposed. But plants or animals that live in water or that fall into or are washed into lakes, streams, or swamps after they die are more likely to be preserved. In water or mud, decomposition is not rapid or may not happen at all.   plants and animals with hard parts like shells and 

bones and stems don't decompose very quickly, and are more likely to form fossils.  Delicate organisms like jellyfish and soft plants do not usually retain their shape long enough for a fossil to form.  

  Describe these types of fossils or fossilization processes: 

a.  mineralization: Under weight (due to overlying water and layers of mud or sand) and over long periods of time, the materials which made up the body of the plant or animal are leached out and replaced with minerals. It causes the formation of a replica of the organism in hard stone, including internal structures.  

b.  mold: the tissues may dissolve and wash away, 

leaving a space with the form of the original organism that will be filled in by a harder material. This forms a mold (the cavity) or cast (filling of the cavity) of the animal or plant, but the internal structures are not preserved.  

c.  cast: filling of the cavity

d.  trace:formed by activities of an organism, for instance when animal 

footprints are left in mud which later hardens and preserves the shape of the footprint.  Another example would be the tunnels left behind as worms burrowed through the mud.  We don’t actually have any part of the organism as a fossil but we do have evidence of their activity. This is often the only evidence of an organism’s behavior. 

  How does the relative dating of fossils work?  Under what conditions is it not 

reliable? 

This method involves comparisons of the sequence of layers in 

which fossils are found.  When fossils are found in undisturbed rock, those on the bottom are the oldest and those on top the youngest.  

  Describe faunal succession. 

specific sequence of fossilized organisms that is found in a series of rock layers

How do radioactive isotopes get into living organisms? 

 Explain how absolute dating works. 

uses radioactive isotopes (isotopes 

are different forms of the same chemical element) that are found in all matter to estimate how long ago the object was formed. 

You are given a fossil to date using 14C.  You can assume from its size that when alive it contained 500 units (or atoms) of 14C.  It now contains 62.5 units.  Approximately how old is it?   

27.  What are the assumptions made in using absolute (radiometric) dating? 

 the rate of assimilation of 14C into living tissue and the 

rate of decay have been relatively constant over time.

 What is the relationship between the difference in the DNA of two species and the time of divergence of their evolutionary history (split from a common ancestor)? 

 the longer ago the evolutionary history of 

two species diverged, the more differences have accumulated in their DNA.  

 What assumption can be made about plants or animals that have similar body structures?  Why is this assumption valid? 

  Plants or animals that have similar 

body structures are assumed to be closely related.  The reason for this assumption has to do with where those structures came from—they were inherited from a common ancestor.

What assumption can be made about plants or animals that have similar embryos? 

The reason vertebrates all look alike during early development is that we all inherited the genes that control embryonic development from a common ancestor.   So we can use that knowledge to work backwards and try to figure out how closely related two species are by comparing their embryos.  If they look similar and go through the same sequence of changes, they are probably closely related. 

What did the distribution of plants and animals he observed suggest to Charles Darwin? 

 in each part of the world they evolved gradually over many thousands of years, and that evolution did not follow the same pathway in all parts of the world.

Describe artificial selection. 

humans, not nature, choose the characteristics that we want to develop in plants or animals.

How did Charles Darwin convince his contemporaries that natural selection was real? 

He understood that people could not refute the effects of selective breeding.  So in the first book he published on evolution, the first few chapters deal with agriculture. Most of the scientists understood that.

 Describe the observations on which Darwin based his theory of natural selection. 

1)  all species produce more offspring than are needed to maintain their populations  (replace the parents), and not all of the offspring survive 

2)  in any species, there are differences between individuals that are passed from  generation to generation (inherited) 

3)  some of the individuals in a population have more offspring than others. 

 What two things did Darwin infer from his observations? 

1)  the individuals who inherited a set of characteristics that best allowed them to survive in their environment were the ones who had more offspring (this is 

called differential reproductive success) 

2)  because their offspring will make up a larger proportion of the next generation, the  traits will become more common. 

What did Charles Darwin and Alfred Wallace figure out? 

the environment acts on populations to “select” the 

individuals that have the best ability to survive and reproduce.  That guarantees that succeeding generations will have the traits that allowed survival and reproduction in higher proportions.   This is the basic mechanism of evolution. 

Evolution can be defined as a change in the __________ ___________ of a 

_____________________ over time. 

What are the two conditions required for evolution in a population? 

1)  there must be genetic variation  

2)  there must be pressure from the environment that favors one combination of DNA over others. 

Genetic variation stems from what two processes? 

changes in the DNA called mutations, and gene shuffling during sexual reproduction.   

Define mutation. 

random and accidental but permanent changes in DNA.  Some are 

very small--only one unit of DNA (one nucleotide) is miscopied.  That may seem minor, but the human diseases cystic fibrosis and sickle cell anemia are caused by just such a mutation.  Then there are larger and larger errors in copying that can involve large parts of the DNA being either lost, duplicated, or put in the wrong place so it won't work correctly.   

Describe the two factors that cause mutations. 

1)  Errors in Copying During Reproduction – Because there are so many 

nucleotides (billions) in the DNA, there are many chances for mistakes to be made.  Even with error-correcting enzymes in the cells, mistakes happen every so often during copying. 

2)  Direct Damage Caused by Exposure of Cells to Radiation or Chemicals – Exposure to ultraviolet light from the sun, radioactivity or certain chemicals can break apart the DNA molecules so that they don't work right.  Because all life is based on the same genetic code, carried by DNA, all living things are susceptible to these same harmful effects.   

Describe the three possible effects of (or results of) mutations on evolutionary 

fitness. 

The first is that the mutation is harmful.  It decreases the evolutionary fitness of the organism (decreases the organism's ability to survive and reproduce).  Most mutations are thought to be harmful, because they disrupt some normal function.  The second possible effect is beneficial.  In this case the mutation increases the fitness of the individual.  Beneficial mutations are assumed to be very rare.  And last, a mutation can be neutral, that is, it causes no change in fitness.   

Mutations in which cells become part of the gene pool of a population? 

 What are the effects of a beneficial mutation? 

Describe the process of recombination. 

When the parent organism is making eggs or sperm, the DNA gets shuffled just a little bit before it is put into the egg or sperm cell.  Just like when we shuffle cards between games so that it is unlikely anyone would get the same hand in the next game, certain parts of the DNA are shuffled around so that each egg or sperm cell gets a slightly different combination of genes.   

  What effect does recombination have on the offspring of sexually reproducing organisms? 

causes them to be a little different from their parents and the other offspring.

Explain the relationship between natural selection and adaptive evolution. 

Natural selection acts on populations to “select” the individuals that have the best ability to survive and reproduce.  The result is adaptation to the environment, so we also call it adaptive selection or adaptive evolution.  Natural selection adapts a population to its environment by increasing or maintaining the DNA for favorable traits in the gene pool of a population. 

What is the tradeoff value of sexual selection for the male? 

The trait that confers mating advantage to the male increases his 

evolutionary fitness because he will mate with more females.  However, the same trait (the peacock's tail, for example) may be a serious liability when he has to escape from predators.   It may seriously shorten his lifespan.  So, the fitness advantage of the trait (mating with more females) must offset the survival disadvantage (shortened lifespan), or sexual selection would not occur. 

Define adaptation and describe some different kinds of adaptations. 

 any trait that allows an organism to be successful (to survive and 

reproduce) in a given environment. These traits might be physical traits such as thick fur, large flowers, or good eyesight. They might also be behavioral traits such as hunting techniques (for predators) or evasion techniques (for prey). Interactions with other species can also be adaptations if they improve evolutionary success (this is called coevolution and will be covered in more detail in a later unit).   

 How do organisms get adaptations?   

 Describe the process of adaptation in a population of mosquitoes that are 

repeatedly sprayed with insecticide. 

Can bacteria become “immune” to drugs? 

Natural selection refers to the survival and reproduction of which individuals? 

What are sneaker males? Describe their method of increasing their evolutionary success. 

What are satellite males? Describe their method of increasing their evolutionary 

success. 

 These smaller and otherwise less desirable males sit around waiting for females to show up when the "big strong" male frogs sing to attract the females. (This is typical in frogs and toads.  The male sits somewhere and makes a lot of noise and the females go to him.) On her way to get to the big frog, a female is intercepted by a satellite male who will fertilize her eggs before the big male ever has a chance.  

What are the advantages of being a sneaker or satellite male? 

they are less obvious to predators and have less of a risk of being eaten while sneaking around fertilizing eggs, while the big strong male has to fight off both other big strong males AND predators. 

 How is fitness measured in plants? 

physical strength, or any kind of strength, is irrelevant. 

Evolutionary success (that's what the word "fitness" means in evolutionary biology) is measured in terms of the number of offspring produced. So a plant that produces more seeds because it has bigger, showier flowers and more pollinators is more fit than a plant that makes fewer seeds because its flowers aren't as good at attracting pollinators.  

How do squid mate? 

What advantage is there to the fertilization method used by sneaker squid? 

What is the disadvantage of being a type I toadfish?

 How do the type I and type II toadfish reproductive organs compare in size? 

 Explain the statement “Evolution is not progress.” 

 Populations simply adapt to their current 

surroundings.  They do not necessarily become "better" in any absolute sense over time.  A trait or strategy that is successful at one time may be unsuccessful at another.

Define teleology.  What phrase is commonly found in teleological statements? 

A common pitfall in science is attributing a sense of purpose to other living things or processes, or using ultimate purpose or design as a way of explaining natural phenomena. "In order to" is commonly used

 Define phylogeny. 

 the study of the evolutionary history of organisms

 What is shown on phylogenetic trees? 

The relationship between different species or other groups is represented by branching diagrams called evolutionary trees

On a phylogenetic tree, what is represented by 

a.  the location of the branch points 

b.  the positions of the species on the tree 

a.relative time of origin of different groups.

b. indicate the closeness of the relationship

From the phylogenetic tree showing evolution from earliest cells, which group is most closely related to animals? 

 How is the process of science applied to a group of phylogenetic trees showing different possible relationships among groups of organisms? 

Early in the study of a group of organisms many different trees, showing different relationships, common ancestors and lines of descent are created, then they are tested against factual evidence and the trees that contain any contradictions to current knowledge are eliminated. This may still leave many possible trees to describe the relationships in a group of organisms (like flowering plants, or primates, or even humans) but the possibilities are constantly narrowed down by subjecting each hypothesis tree to more and more stringent testing. The evolutionary trees shown in the study guide have been tested repeatedly and represent the best description we have based on current knowledge. But every now and then a new fossil is discovered, the trees are tested again, and some of them are rejected. Science is a process of elimination.  

Explain why humans use classification systems and the limitations of the systems we use. 

 Grouping helps us to simplify--it reduces large and complex systems into smaller, less complex systems. But the problem is that the categories we use are arbitrary and the boundaries we have stipulated between groups are artificial. They are not part of the real world; they exist only in our minds. So it's not surprising that the real world often doesn't fit neatly into our categories. But our systems of organization are useful anyway because without them we couldn't understand relationships between organisms.  Classification also allows us to make generalizations about the members of a group, applying knowledge gained from one member to all of the members. 

 Explain how the process of classification works. 

works by looking for similarities between organisms and putting the most 

similar things together in the same group. 

What kinds of structures have been used in classification? 

At first it was large and mostly external features like flowers in plants, body plans in invertebrates or feathers in birds.  As technology got more sophisticated we moved on to comparisons of internal organs, embryos, behavior and chemical composition.  Microscopes allowed us to use the structure of tissues and cells to look for similarity, and finally we have been able to look at the internal instructions, the DNA, and compare it in different species to see how closely they are related and to hypothesize about who our common ancestors were. 

What is the key evidence that all living things descended from the same common ancestors? 

 all living things are made of the same chemical elements (carbon, hydrogen, oxygen, nitrogen) and basic molecules (amino acids, sugars, fats and nucleic acids). 

What assumption can be made about two different organisms that have the same type of cell or tissue in their bodies? 

What is taxonomy? 

the process of identifying and classifying species. 

 List the levels of taxonomic classification, from largest to smallest. 

Kingdom: Animalia 

   Phylum: Chordata 

    Class:  Mammalia 

     Order:  Rodentia 

      Family: Sciuridae 

       Genus: Sciurus 

        Species: Sciurus niger 

What are the parts of a scientific name? 

What are the rules for writing out a scientific name by hand?  In print? 

should be underlined when hand-written or written in italics when 

printed

Define a species, using the biological species concept. 

ollection of similar organisms that are capable of interbreeding under natural conditions and producing live, fertile offspring. 

What two conditions are necessary for individuals to belong to the same species? 

  First, the members of a species can interbreed and will interbreed in the wild.  Secondly, live and healthy offspring can be produced, which in turn are capable of having offspring. 

 Describe the Five Kingdom classification system.  Describe the characteristics of the organisms in each Kingdom

KINGDOM MONERA 

The members of this group have one common characteristic: a prokaryotic cell. A prokaryotic cell is typically small with no internal organelles in the cell. Even the DNA is not contained in a separate nucleus. The DNA is usually arranged in one circular ring. The organisms that are placed in this kingdom are bacteria and cyanobacteria (formerly called blue greens). Bacteria, as a general rule, are heterotrophs. Cyanobacteria are photosynthetic. 

KINGDOM PROTISTA 

The members in this group share two characteristics: they are (1) eukaryotic and (2) unicellular, colonial or simple multicellular organisms. A eukaryotic cell contains internal organelles, each with its own function. The DNA is contained inside a nucleus. The DNA is typically arranged in strands that are called chromosomes. Members of this kingdom include algae (green algae, diatoms), protozoans (Euglena, Amoeba, Paramecium), slime molds and water molds. 

KINGDOM PLANTAE 

The members of this group are multicellular, eukaryotic and make their own food by means of photosynthesis. Organisms include mosses, ferns, horsetails, conifers, flowering plants and other plants. 

KINGDOM FUNGI 

The organisms in this kingdom are multicellular, eukaryotic and heterotrophic. The major characteristic shared by the members of this group involves their method of digesting food: they secrete chemicals outside of their bodies onto food particles, digestion occurs outside the body, and then the fungus absorbs the digested particles.  The organisms in this group include mushrooms, molds and yeasts. 

KINGDOM ANIMALIA 

The organisms in this kingdom are multicellular, eukaryotic and heterotrophic. The members of this group bring food into their bodies, internally secrete chemicals to break down the food substances and then absorb the particles. Organisms include invertebrates (sponges, worms, crustaceans, etc.) and vertebrates (fishes, reptiles, mammals, etc.). 

 Describe the Three Domain classification system.  Describe the characteristics of 

the organisms in each Kingdom. 

One level above a kingdom

Domain Bacteria (eubacteria or "true bacteria") contains the simple prokaryotic life forms described above in Kingdom Monera. These are unicellular organisms that usually lack a nucleus. This includes bacteria and cyanobacteria.  

Domain Archaea (Ar kee uh) contains the simple life forms called archaeans, formerly part of Kingdom Monera. This prokaryotic group includes thermoacidophiles that live in very hot acidic environments, methanogens that produce methane gas, and halophiles that live in very salty environments. Recent analysis of the 1,738 genes of a species of this group showed that about half of its genes were totally unique. (In other words, these genes have not been found in any other plant, animal, bacterium, protist or fungus).  

Domain Eukarya (U care ee uh) contains complex organisms (the eukaryotes) that havefungi.  

 Describe how the Three Domain classification system affects the Five Kingdom 

classification system. 

Domain Eubacteria and Domain Archaea replace the old kingdom 

Monera. The other four kingdoms (Protista, Plantae, Fungi and Animalia) fall under Domain Eukarya. However, molecular evidence now indicates that the protistans are not closely related to each other. This kingdom will probably be split into several separate kingdoms. While there will be some changes to the other three kingdoms (Plantae, Fungi and Animalia), the members of these kingdoms are closely related to each other and the kingdom names are still in use today. 

 What is the function of DNA? 

What happens during replication? 

How does the DNA of the daughter cells compare to the DNA of the parent cell? 

 Describe a chromosome.   

In eukaryotes, nuclear DNA and protein form long structure.

Each  is a twisted, double strand of DNA. 

 How many types of subunits (nucleotides) occur in DNA?  If all living things have DNA made of the same nucleotide subunits, why are we different? 

4

 Differences in the order of the nucleotides makes individuals in a species 

different from each other, and even greater differences in nucleotide order make species different from each other. 

What is a gene and what is its function? 

How does the genetic code explain the relationship between all living things? 

all living things use the same genetic code.  If we had no genetic 

relationship to each other it would be very, very unlikely that we all used the same genetic code. 

 Describe asexual reproduction. 

offspring are produced by a single parent, so each offspring has a copy of DNA that is identical to that of its single parent.  In these organisms genetic variation comes only from mutations. 

Describe sexual reproduction. 

each offspring gets half of its DNA from each of its 2 parents, so 

each offspring is genetically different from both parents and from other offspring of the same parents.  In these organisms, genetic variation comes both from mutations and recombination (shuffling).  

 How do sexually reproducing organisms prevent the continual doubling of their chromosome number? 

organisms have to make special cells with half the regular chromosome number, yet containing one full set of genes.  The process used to do this is called meiosis.  

 Describe the process of meiosis. 

starts in diploid cells in sex organs.  (In animals, the sex organs are the ovaries or testes.)  Diploid cells have two full sets of chromosomes--one from the organism's  mother and one from its father.  Meiosis separates the chromosomes into two complete but separate sets.  But during the process, the original chromosomes that came from the parents are shuffled and dealt out randomly to the new cells being formed (recombination or shuffling).  The new cells with only one set of chromosomes are called haploid.  Then a male haploid cell joins with a female haploid cell during fertilization to produce a new individual called a zygote.  Because the zygote contains two full sets of chromosomes, it is diploid.   

These observations led Charles Darwin to the conclusion that species are not 

____________ forever, but that they can change to ______________ to the 

conditions of their environment. 

 According to Darwin’s idea of natural selection, individuals of the same species are not absolutely _________________.  Some of the young Galapagos tortoises may be born with slightly ____________________ necks than others.  In times of drought they will be able to reach leaves and live, while the shorter-necked ones _________.  So those best fitted to the environment will transmit their characteristics to their_____________________.  After countless generations the tortoises on arid islands will have _____________________ necks than those on well watered ones and so one species will have given rise to another.