Final Exam

what are sister taxa on a phylogenetic tree?

two organisms with the most recent common ancestor

what are the two kinds of error?

-random error: often the result of variability of the environment. always present -systematic error: due to bias. there is error in a consistent direction in the measurements

are mutations random?

-some mutations are more likely -some genes or areas of the genome are more prone to mutation

what is the competition interaction? what is the effect on each species (species 1/species 2)?

-species are both using the same resources and thus each species negatively affects the other species (-/-)

what is the difference between standard deviation and standard error?

-standard deviation: a measure of the variability of the sample -standard error: a measure of how close the estimated mean is likely to be from the true population mean

what are inferential statistics?

-statistical tests that have been created to allow a researcher to make a more objective decision about hypothesis acceptance or rejection -use information from descriptive statistics to make decisions or predictions about a population

how does energy enter the energy pyramid? how is the energy lost?

-sun's energy -lost as heat

what are examples of inferential statistics?

-t test -chi-square test -correlation -regression

what is the purpose of the t test?

-to determine the difference between two groups -told us if average measurements from two groups are different or not -null hypothesis: the difference between two means is zero

what is cell determination?

-when the type of cell it will become has been determined -regulatory genes are expressed but do not change the appearance of the cell but the expression controls the expression of a series of other genes. the cell fate of the cell is set

what is causation?

the concept that the size of variable X results in some effect on the size of variable Y

What are descriptive statistics?

to organize, display, and describe data using tables, graphs

what are homologs?

members of a homologous pair

what are examples of discrete ordinal data?

months (jan, feb, march) or flower petals (3, 4, 5)

what are common misconceptions about evolution?

-it is totally random -it is simply survival of the fittest -it is always adaptive -evolution is a march in progress (modern organisms are more adaptive)

what are examples of the measures of central tendency (descriptive statistic)?

-mean -median -mode

what does wildtype mean?

-means that the organism has no mutations or is "normal" -the wildtype phenotype is the phenotype that is commonly found in the wild

what are the two types of descriptive statistics

-measures of central tendency: ways of estimating the value for a typical member of the sample -variability within the sample: the standard measure of variation

what are the four mechanisms of evolution?

-mutation -gene flow -genetic drift -natural selection

what are the two major problems of the idea of blending inheritance?

-not all characteristics show up as an intermediate in offspring -under blending inheritance, all variation in characteristics would be lost within a few generations

difference between p<0.05 and p>0.05

-p<0.05: reject the null (low probability that the difference is only due to chance) we infer that the groups are different -p>0.05: fail to reject the null (high probability that the difference is only due to chance) we infer that the groups are not different

what is the difference between parasitism and parasitoidism?

-parasitism: feeding on a host organism without killing it -parasitoidism: feeding on a (single) host organism and killing by consuming most of it (sort of half-way between predation and parasitism)

what are examples of the consumption interaction?

-predation -herbivory -parasitism -parasitoidism

what is the genetic drift mechanism of evolution?

-process of evolution in which allele frequencies change due to chance events -genetic drift is a non-adaptive process

what is the purpose of t-value vs the purpose of chi-square value

- t value: measure of difference- the higher t is, the more different the groups are - chi-square value: measure of difference, the higher chi-square is, the more different observed is from expected

what is the mutation mechanism of evolution?

-accidental changes in the DNA sequence of an organism

what is adaptation? which evolutionary mechanisms is responsible?

-adaptation is a feature that provides some improved function for a population of organisms -natural selection is the only mechanism that is responsible for adaptations

which trophic level do decomposers feed on? what is their purpose?

-all trophic levels -they recycle nutrients

what is a character matrix when building a phylogenetic tree?

-assigning values to traits -presence of character = 1 -absence of character = 0

what is the point of a chi-squared test?

-can tell us if our punnett square models and the data are different or not -null hypothesis: the difference between observed proportions of individuals of a certain phenotype and expected proportions is zero

what are the two ways you can think of evolution?

-descent with modification -changes in allele frequency

what are the two types of ordinal data?

-discrete: categories that have an order -continuous: have order but not categories

what is categorical data? Examples?

-distinct categories that have no order -Ex: types of horses (palominos, paints, buckskins)

what are the factors that influence decisions of reproductive strategies?

-environmental conditions -competition for resources -quality of resources -food abundance

What are orthologous genes?

-genes in different species derived from teh same ancestral sequence -retains the same or similar function

what are hemimetabolous insects?

-have a juvenile stage tat is similar to the adult stage -juvenile stage is called a nymph and it is essentially a miniature version of the adult without wings

what are holometabolous insects?

-have a juvenile stage that is completely different from the adult stage -juvenile stage is called a larva. at the end of the larval stage, there is a pupal stage in which the insect is dormant and the body is completely reorganized into the adult form

what are homologous structures?

-homologous structures are similar in origin but not function (whale flippers /human arms) -similar in structure but different in function

what is a phylogenetic tree? what's its purpose?

-is a hypothesis describing the proposed evolutionary history of a group of related organisms -are used to help analyze the pattern of evolution

The variance for a sample with values 2,2,2,6,6, and 6 is ___. A. 4.8 B. 2 C. 5 D. 2.5

A. 4.8

what are the arrows on a phylogenic tree pointing to? A. a node B. a terminal taxon C. the root of the tree D. a branch

A. a node

A cell in an embryo that still resembles the original cells of that embryo but will eventually form the spinal cord is ___. A. determined only B. differentiated only C. determined and differentiated D. neither determined nor differentiated

A. determined only

A scientist wants to test the idea that temperature affects the rate at which crickets 'sing' (technically called stridulation). She places crickets in different temperatures and records the singing rate. The temperature to which crickets are exposed is the ___. A. independent variable B. dependent variable C. hypothesis D. most accurate measurement

A. independent variable

A measurement that is highly accurate has which of the following characteristics? A. it is very close to the 'true' value B. it is highly repeatable C. it is biologically meaningful D. both A and B

A. it is very close to the 'true' value

Two flies that are both homozygous for the fast allele of alcohol dehydrogenase are mated (neither has mated previously). They have many homozygous fast offspring and one offspring that is a heterozygote. What evolutionary force is responsible for this result? A. mutation B. migration C. genetic drift D. natural selection

A. mutation

A community is a group of __________________ of different species that all occur in the same area. A. populations B. ecosystems C. offspring D. genomes

A. populations

A species interaction in which one species benefits and another species does worse than it would if it was alone is known as ___. A. predation B. mutualism C. photosynthesis D. production

A. predation

If a sample of 36 measurements has a variance of 25, what is the standard deviation? A. 6 B. 5 C. 25/36 D. 5/6

B. 5

You have guinea pigs from two pure breeding lines. One line has black fur and red eyes and the other line has white fur and blue eyes. When you cross them, all the F1 guinea pigs have black fur and blue eyes. When you cross the F1s to one another, you get a total of 50 F2 offspring. There are 31 with black fur and red eyes, 15 with white fur and blue eyes, 2 with white fur and red eyes, and 2 with black fur and blue eyes. There are approximately equal numbers of males and females in each phenotypic category. What is the expected phenotypic ratio in the F2 assuming independent assortment? A. 3:1 B. 9:3:3:1 C. 1:1:1:1 D. 1:1

B. 9:3:3:1

Which of the following is true because of the fact that only about 10% of food is used to make more biomass? A. High trophic level organisms are usually very common B. High trophic level organisms are usually uncommon C. middle trophic level organisms are usually uncommon D. middle trophic level organisms are usually very common

B. High trophic level organisms are usually uncommon

You have guinea pigs from two pure breeding lines. One line has black fur and red eyes and the other line has white fur and blue eyes. When you cross them, all the F1 guinea pigs have black fur and blue eyes. When you cross the F1s to one another, you get a total of 50 F2 offspring. There are 31 with black fur and red eyes, 15 with white fur and blue eyes, 2 with white fur and red eyes, and 2 with black fur and blue eyes. There are approximately equal numbers of males and females in each phenotypic category. Based on what you know, what kind of cross is being done here? A. autosomal monohybrid cross B. autosomal dihybrid cross C. sex-linked monohybrid cross D. sex-linked dihybrid cross

B. autosomal dihybrid cross

Herbivory and predation are both examples of which type of ecological interaction? A. mutualism B. consumption C. competition D. commensalism

B. consumption

The control of transcription of DNA and translocation of mRNA is most accurately described as ___. A. control of cell fate B. control of gene expression C. control of differentiation D. control of determination

B. control of gene expression

A scientist wants to test the idea that temperature affects the rate at which crickets 'sing' (technically called stridulation). She places crickets in different temperatures and records the singing rate. The singing rate is the ___. A. independent variable B. dependent variable C. hypothesis D. most accurate measurement

B. dependent variable

A measurement that is highly precise has which of the following characteristics? A. it is very close to the 'true' value B. it is highly repeatable C. it is biologically meaningful D. both A and B

B. it is highly repeatable

The value (sum of all measurements/total number of measurements) for a sample is known as the ___. A. median B. mean C. mode D. variance

B. mean

What does the law of segregation state? A. in an organism, each locus has two alleles B. only one allele per locus is present in each gamete C. only one trait can be inherited per locus D. A and B

B. only one allele per locus is present in each gamete

Organisms that feed upon plants are known as ___. A. producers B. primary consumers C. secondary consumers D. ovipositors

B. primary consumers

Which of the following is NOT the cause of problems when using morphological characteristics to construct a phylogeny? A. rapid evolution during adaptive radiation B. slow gradual change in traits over time C. convergence D. lack of shared characteristics among taxa

B. slow gradual change in traits over time

Why is it important to use individuals from pure breeding lines to start crosses? A. to remove any effects of linked genes B. to ensure the individuals are homozygous C. to ensure the individuals are heterozygous D. to test the dominance relationship between the alleles

B. to ensure the individuals are homozygous

You have guinea pigs from two pure breeding lines. One line has black fur and red eyes and the other line has white fur and blue eyes. When you cross them, all the F1 guinea pigs have black fur and blue eyes. When you cross the F1s to one another, you get a total of 50 F2 offspring. There are 31 with black fur and red eyes, 15 with white fur and blue eyes, 2 with white fur and red eyes, and 2 with black fur and blue eyes. There are approximately equal numbers of males and females in each phenotypic category. If you were to do a χ2 test on the data, what would the expected value be for the individuals with white fur and blue eyes? A. 15 B. 12.5 C. 9.375 D. 3.125

C. 9.375

The allele for white hair in mice is autosomal recessive (b), while the allele for black hair is autosomal dominant (B). A white, female mouse mates with a black, male mouse. If the offspring are half black and half white, what are the possible genotypes for the black, male mouse? A. Bb or bb B. BB only C. Bb only D. bb only

C. Bb only

What is the difference between an allele and a gene (locus)? A. they are exactly the same B. allele applies to genes on the sex chromosomes C. an allele is a particular version of a gene D. an allele is always dominant

C. an allele is a particular version of a gene

You have guinea pigs from two pure breeding lines. One line has black fur and red eyes and the other line has white fur and blue eyes. When you cross them, all the F1 guinea pigs have black fur and blue eyes. When you cross the F1s to one another, you get a total of 50 F2 offspring. There are 31 with black fur and red eyes, 15 with white fur and blue eyes, 2 with white fur and red eyes, and 2 with black fur and blue eyes. There are approximately equal numbers of males and females in each phenotypic category. Which alleles are dominant? A. black, red B. black, white C. black, blue D. white, blue

C. black, blue

A scientists adds fertilizer to the soil in a grassland and measures a change in the insects feeding on the plants. This change is an example of which of the following? A. mutualism B. competition C. bottom-up control D. top-down control E. an energy pyramid

C. bottom-up control

What type of data is analyzed using a chi-squared ( χ2 ) test? A. continuously varying measurements B. mean values for different groups C. counts D. all of the above

C. counts

A cell in the nervous system of a late stage fetus is ___. A. determined only B. differentiated only C. determined and differentiated D. neither determined nor differentiated

C. determined and differentiated

Which evolutionary force is most powerful in small populations? A. mutation B. migration C. genetic drift D. natural selection

C. genetic drift

The use of DNA sequences to estimate phylogenies is based on the idea that DNA sequences in different taxa can be ___. A. convergent B. parsimonious C. homologous D. interesting

C. homologous

A scientist wants to test the idea that temperature affects the rate at which crickets 'sing' (technically called stridulation). She places crickets in different temperatures and records the singing rate. The proposal that the singing rate depends on temperature is the ___. A. independent variable B. dependent variable C. hypothesis D. most accurate measurement

C. hypothesis

An insect that is holometabolous is distinguished by which of the following? A. it can fly B. it has six legs C. it has a pupal stage D. young are called nymphs

C. it has a pupal stage

What types of genes are typically activated during determination? A. genes coding for enzymes B. genes coding for structural proteins C. regulatory genes D. no genes

C. regulatory genes

If you do a t-test and you get p<0.04, what does the value mean? A. the two means you are comparing are different B. the populations you are comparing have different means C. the probability that the two populations have the same mean is less than 4% D. none of the above are true

C. the probability that the two populations have the same mean is less than 4%

You are studying the enzyme alcohol dehydrogenase in a population of Drosophila. The allele frequency of the fast allele is 0.3 and the allele frequency of the slow allele is 0.7. Assuming the population is in Hardy Weinberg equilibrium, what is the expected frequency of heterozygotes in the population? A. 0.21 B. 0.09 C. 0.49 D. 0.42

D. 0.42

If a sample of 36 measurements has a variance of 25, what is the standard error? A. 6 B. 5 C. 25/36 D. 5/6

D. 5/6

A succulent plant is grown in a low light situation so that it is very tall. pale, and has few leaves compared to its siblings grown in full sun. Is this an evolutionary change or not, and why? A. not evolution because no genetic changes B. evolution because phenotypic change C. not evolution because phenotypic change D. A and C

D. A and C

The allele for white hair in mice is autosomal recessive (b), while the allele for black hair is autosomal dominant (B). A white, female mouse mates with a black, male mouse. What are the possible genotypes for the white, female mouse? A. Bb or bb B. BB only C. Bb only D. bb only

D. bb only

The study of species diversity and the role of interactions among species in influencing diversity is known as ___. A. ecosystem ecology B. population ecology C. behavioral ecology D. community ecology

D. community ecology

Why is a food web a more accurate representation of a community than a food chain? A. most organisms are specialists and have only one food source B. food webs incorporate competition and mutualism unlike food chains C. food chains don't tell you at what trophic level each species occurs D. food webs can show that species can occur at multiple trophic levels

D. food webs can show that species can occur at multiple trophic levels

Insect herbivores differ from mammalian herbivores in which of the following ways? A. insects never harm the plants they eat B. insects only eat plants that are distasteful to humans C. each insect species eats many different plant species D. insects tend to be more specialized in the plants they eat

D. insects tend to be more specialized in the plants they eat

what is a node in a phylogenetic tree?

a speciation event

A large sample of flies from the population in question 2 is moved to a new habitat. There are no flies existing there. There is a lot more fermenting fruit (and thus alcohol) in this environment compared to the original environment. Over 10 generations, the frequency of the fast allele increases from 0.3 to 0.6. What evolutionary force is responsible for this result? A. mutation B. migration C. genetic drift D. natural selection

D. natural selection

Why is the combination of DNA data and parsimony so powerful? A. parsimony does not apply to DNA sequences, so it is not powerful B. most DNA data is non-coding and cannot be used except in parsimony analyses C. DNA has only 4 possible character states D. parsimony maps the evolution of each base in the sequence so there are a huge number of characters

D. parsimony maps the evolution of each base in the sequence so there are a huge number of characters

The production of a new structure, following the removal of an existing structure, in an adult animal is known as ___. A. cell fate B. determination C. differentiation D. regeneration

D. regeneration

what does it mean for the p<0.05

If P < 0.05, it means that there is a < 5% probability that the result occurred by chance. a P<0.05 means that we are able to reject the null hypothesis

what is regeneration?

ability to regrow tissue that has been damaged

what is a model system?

We use these selected organisms to study the mechanisms of life. It is a representative organism or cell type used for experiments. They are easy to grow, manipulate, and study.

what is the alpha value in statistical tests?

accuracy index (degree of accuracy)

what is the difference between accurate measurements and precise measurements?

accurate: low bias (low systematic error) even though it might (or might not) have high random error precise: low random error even though it might (or might not) have high systematic error

what is an apex consumer?

any species that is in the highest trophic level in a community

what is a null hypothesis?

basically the opposite of the hypothesis, stating the effect that you hypothesize doesn't exist

why is plant choice during oviposition of holometabolous insects important?

because the larvae of holometabolous insects are mostly not very mobile

what is the mutualism interaction? what is the effect on each species (species 1/species 2)?

both species benefit the other species by their presence by providing a resource the other lacks (+/+)

why is standard deviation regularly used instead of variance?

by square rooting the variance, the units used for the standard deviation are able to be the same units as the variable

are mutations harmful?

can be positive, neutral or negative

what is ordinal data?

data that have an order to them

what are the two types of statistics?

descriptive statistics and inferential statistics

what is the natural selection mechanism of evolution?

differential success in reproduction of different, heritable phenotypes resulting from the interaction of organisms with their environment

what are convergent structures?

functionally similar traits due to convergent evolution and not common ancestry (bat wing/bird wing)

what is biosphere ecology?

global processes

what is a clade in a phylogenetic tree?

group of organisms that include the ancestor and all the descendants

what are examples of continuous ordinal data?

height, weight, etc.

what decreases the effect of genetic drift?

increased population size

what does a higher t-value mean?

increasing t-values represent an increasing difference between the two groups. this means there's greater evidence against the null hypothesis

what are the two types of variables?

independent (x-axis) and dependent (y axis)

what is the purpose of the Title section of a scientific paper?

informative title for referencing

what is ecosystem ecology?

it is concerned with two fundamental questions having to do with the interaction of biotic (living) and abiotic (non-living) components of organisms -Question 1: how do organisms facilitate the movement of matter (nutrients) and energy through different parts of ecosystems -Question 2: how does the movement of nutrients and energy affect the abundance of organisms at different trophic levels (energy flux and cycling of nutrients)

what is a top-down trophic cascade?

it is the highest trophic levels that strongly affect the abundance of other species (increased secondary consumers cause increased producers)

what does it mean if the t-test results are significant?

it means that the observed p-value is less than the significance level defined in the study

why is it important to identify which is your independent variable and which is your dependent variable?

its important because it tells you what you need to measure

what is the commensalism interaction? what is the effect on each species (species 1/species 2)?

one species benefits from the interaction and the other derives neither benefit nor harm (+/0)

what is an outgroup?

one species in a phylogenetic tree that differs from all the others

what is the consumption interaction? what is the effect on each species (species 1/species 2)?

one species is a resource (food) for the other. thus, one species benefits from the interaction and the other is negatively impacted (+/-)

what is physiological ecology?

physiologies of individual organisms interact with the environment

what is the gene flow mechanism of evolution?

process of evolution in which individuals migrate from one population to another resulting in changes in allele frequencies

what is the purpose of the Introduction section of a scientific paper?

provides background on the topic and outlines authors' questions/hypotheses

what is the purpose of the Methods section of a scientific paper?

provides detailed experimental notes

what are sister taxa?

relatively most closely related organisms

what is the purpose of the Results section of a scientific paper?

reviews findings and statistical tests

what kind of questions does science ask?

science asks testable questions that can be turned into hypotheses

how does an increase in sample size affect the standard deviation and standard error?

standard deviation can stay high (because the population is variable) but the standard error will go down as your estimate of the mean gets better

what is behavioral ecology?

studies how individuals interact with their environment through behavior

what is population ecology?

studies of how the environment affects characteristics of a population. population ecology is concerned with understanding why species are common or rare, why they might have many offspring or few, and why a population might be growing or shrinking (population dynamics; the unit of evolution)

what is the purpose of the Abstract section of a scientific paper?

summarizes and highlights main points

what is the purpose of the Discussion section of a scientific paper?

summarizes results in light of hypotheses and compares to other studies, suggests future studies/questions

what is organism ecology?

survival and reproduction; the unit of natural selection

what is a bottom-up trophic cascade?

the health and vigor of the producers has a strong impact on the rest of community (absence of producers causes decrease in secondary consumers)

what is Mendel's First Law?

the law of segregation: that a parent passes one of its two alleles at a particular locus to each of its offspring. also states that it does so randomly

what is a p-value?

the probability that the result obtained was due to chance. the probability that the null is true. this also represents the probability of getting a false positive for difference

why do organisms at the bottom of the food web have a much greater biomass?

the reason for this is that most energy and matter that is eaten is either lost as waste or used in the maintenance of the organism. only about 10% of the food consumed is used to make more biomass

what is community ecology?

the study of interactions among species and of the factors that influence the number of species occurring in a community. community ecology is fundamentally concerned with understanding species diversity (interactions among populations)

what is ecology?

the study of interactions between organisms and their environment

how are genes named?

they are named after what happens in their absence

what are independent vs dependent studies usually testing?

usually testing hypotheses about causation

what is cell differentiation?

when a cell undergoes physical form changes (it differentiates) after determination

what is parsimony?

when a phylogenetic tree has the fewest evolutionary events (most likely what happened)

what is the purpose of the Literature Cited section of a scientific paper?

where we list the sources of the paper

what does it mean if the chi-square value is smaller than the critical value?

you fail to reject the null hypothesis

what does it mean if the chi-square value is larger than the critical value?

you reject the null hypothesis

how do you find standard deviation?

you take the square root of the variance