BI345 Evolution OSU Midterm

Match the term with the concept. (A) Law of Independent Assortment (B) Law of Segregation (C) Linkage (D) Multiple Genes

(A) the way one pair of genes separates into gametes is unrelated to the way another gene pair separates into gametes. (B) genes of a pair separate into gametes at random (C) genes located on the same chromosome are inherited together as a unit (D) a number of different genes are responsible for the production of an inherited trait

A population of 346 field mice are sampled, revealing 288 black mice and 58 grey mice. The grey phenotype is dominant to the recessive black phenotype. Assuming Hardy-Weinberg equilibrium, what is the frequency of heterozygous individuals? (Choose the best answer)

0.16

Which of the numbered diagrams contain a clade of three species in the colored area?

1

A population of 346 field mice are sampled, revealing 288 black mice and 58 grey mice. The grey phenotype is dominant to the recessive black phenotype. Assuming Hardy-Weinberg equilibrium, what is the frequency of the grey phenotype? (Choose the best answer)

16.7%

Which of the following types of genetically determined traits are also influenced by environmental factors?

All of these (Predisposition to Conditions, Physical Traits, Behavioral Traits)

Which of the following areas provide evidence supporting Darwin's Theory? (Select all that apply)

Artificial selection Homologies Biogeography Fossils

Which of the following terms is not defined correctly? The term coevolution is used to describe cases where two (or more) species reciprocally affect each other's evolution. Artificial selection describes all of the influences that humans have on other species. An adaptation is a feature that is common in a population because it provides some improved function. Sexual selection is a "special case" of natural selection that acts on an organism's ability to obtain or successfully copulate with a mate.

Artificial selection describes all of the influences that humans have on other species.

Match the term with the concept. Mutation Gene Flow Genetic Drift Natural Selection

Changes in DNA Movement of genes from one population to another by migration. Chance changes in gene frequencies from generation to generation. Favorable variants pass genes on preferentially.

Mutations in _____ cells are the only type that are heritable and passed to offspring. (Fill in the blank with a single word)

Correct Answers germ-line egg and sperm sperm and egg eggs and sperm reproductive gamete sex egg or sperm germ sperm or egg sperm and eggs

Mendel crossed purple flowered pea plants and got some white flowered offspring. The purple flowered parents must have been _____ for flower color.(Fill in the blank with a single word)

Correct Answers heterozygous hybrid

Mutations in ___ regions of DNA can change the timing, location, and level of gene activation. (Fill in the blank with a single word)

Correct Answers regulatory switch control

___ mutations occur during gamete production, with the offspring inheriting the mutation from an unaffected parent. (Choose the best answer to fill in the blank)

De novo

Match the term with the concept. Biological evolution Small-scale evolution Large-scale evolution

Descent with Modification Changes in gene frequency in a population from one generation to the next. Descent of different species from a common ancestor over many generations.

A gene is a segment of the RNA molecule that codes for a protein.

False

A homozygous genotype is made up of two different alleles.

False

A population of animals is a group of animals that share a functional role in the environment

False

A theory is a hunch or guess.

False

Bicolor beetles with brown genes escaped predation and survived to reproduce more frequently than bicolored beetles with green genes, so that more brown genes got into the next generation. This is an example of Genetic Drift.

False

Changes in the genes that control development rarely have major effects on the morphology of the adult organism.

False

Cloned organisms are exact copies of the original.

False

Evolution is a process that occurs at the level of the individual organism.

False

Evolution is climbing a ladder toward perfection.

False

If all things are equal, the most complex explanation for how things occurred is probably right.

False

Introns are portions of the DNA that code for proteins.

False

Shared derived characters are used to define outgroup organisms in cladograms.

False

Some dog breeds are a separate species from other dogs.

False

Genetic mutations always alter phenotype but not necessarily genotype.

False (Genotype describes the genetic code of an organism. Thus, any mutation to that code changes the genotype. Phenotype is the expression of a trait. Different genetic codes can lead to the same expression of a trait. For example, a dominant homozygous person (someone who has two dominant alleles for a gene) will express the same trait as a heterozygote person (who has a dominant allele and a recessive allele). Thus, a genetic mutation does not necessarily mean that the phenotypic expression changes.)

You join an expedition to a remote Indonesian jungle, and discover a new species of amphibious turtle. You notice that the species has two neck phenotypes - a long-neck version that allows grazing more deeply in underwater weeds, and a short-neck version that is better at avoiding predation. You monitor 100 individuals from each phenotype for a period of several years, finding reproductive differences between the two. The short-neckers, on average, produce 100 offspring per year with 15 surviving into the next generation. In contrast, the long-neckers produce 130 offspring annually, with 18 surviving into the next generation. Which phenotype has the higher average fitness?

Long-neckers

Which of the following statements about mutations is(are) true? Not all mutations matter to evolution. Mutations can be beneficial, neutral, or harmful for the organism. Mutation is a change in DNA, the hereditary material of life. Mutations are random.

Not all mutations matter to evolution. Mutations can be beneficial, neutral, or harmful for the organism. Mutation is a change in DNA, the hereditary material of life. Mutations are random.

Information in the DNA passes to ____ and then to proteins in what has been called the central dogma.

RNA

A Cladogram is essentially a hypothesis of how you think organisms may be related.

True

A clade is a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor.

True

A problem with cladistic analysis is that shared derived characteristics may arise independently by convergent evolution or be lost by reversal.

True

A shared character is one that two lineages have in common, and a derived character is one that evolved in the lineage leading up to a clade and that sets members of that clade apart from other individuals.

True

According to the idea of parsimony, if all things are equal, the simplest explanation for how something occurs is probably right.

True

An example of gene flow is that some bicolor beetles with brown genes immigrated from another population, or some beetles carrying green genes emigrated.

True

Biological structures are not new, but are instead modifications of pre-existing ones.

True

Biologists use the word fitness to describe how good a particular genotype is at leaving offspring in the next generation relative to how good other genotypes are at it.

True

Both natural and artificial selection rely on principles of inheritance and both bring about change over time.

True

Cladistics assumes that each group has an ancestor that other species do not share.

True

Different versions of a gene with slightly different DNA sequences are the basis of variations within a population of a species.

True

Every somatic cell of every organism contains all the information required to create and duplicate and make variations of itself.

True

Evolution helps us understand the history of life.

True

Evolution only occurs when there is a change in gene frequency within a population over time.

True

Evolutionary fitness is a matter of how well-suited organisms are to their current environment.

True

Humans and chimpanzees are evolutionary cousins and share a recent common ancestor that was neither chimpanzee nor human.

True

Individual organisms don't evolve; populations do.

True

Microevolution is evolution on a small scale - within a single population.

True

Natural selection can only work on structures that are in use.

True

Organisms are now viewed as being divided into three domains: Bacteria, Archaea, and Eukarya.

True

Reznick's observation of evolution by natural selection in wild guppies demonstrated how guppies living in predator free environments developed a whole suite of characteristics that are similar to those of captive populations.

True

Sexual selection and ecological selection often oppose each other.

True

The coding regions of DNA code for the positioning of amino acids in proteins.

True

The nodes of a cladogram are locations where the branches originate and represent a common ancestor.

True

The presence of a dominant allele masks the presence of a recessive allele.

True

Wallace's Line is drawn through the Malay Archipelago. Animals on the eastern islands resemble those of Australia while animals to the west, those of Asia.

True

Your DNA contains about 19,000 to 20,000 genes.

True

Imagine that you go to a mountaintop this year, sample a group of beetles, and determine that 80% of the genes in the population are for green coloration and 20% of them are for brown coloration. You go back the next year, repeat the procedure, and find a new ratio: 60% green genes to 40% brown genes. Have you have detected a microevolutionary pattern (i.e. a change in gene frequency)?.

Yes

A population is a group of organisms that all share _____ . (Choose the best answer) homologous chromosomes a series of genes a common fashion sense a behavioral adaptation a gene pool

a gene pool

The wings of birds and dragonflies are _____ since they are derived from different ancestral structures.

analogous

Microevolution will occur if there is _____ . (Choose the best answer) a small population gene flow natural selection non-random mating any of the above mutation

any of the above

The genetic code is found in the sequence of _____ in DNA.

bases

Match the term with the concept. Radiometric dating Stratigraphy Molecular clocks Half-life

direct dates from decay of radioactive elements relative dates from rock sequences time estimates from genetic divergence time required for a quantity to fall to the half value measured at the beginning of the time period

Selection against an extreme genotype or in favor of an extreme is called _____ selection because the average genotype of a population shifts toward one extreme.

directional

Sexual selection is necessary for differential reproduction.

false

Match the symbols from the Hardy-Weinberg equation with the concept they represent. 2pq q p p2 q2

frequency of the heterozygous genotype frequency of the recessive allele frequency of the dominant allele frequency of the homozygous dominant genotype frequency of the homozygous recessive genotype

"Wildlife corridors", continuous segments of natural habitat that either pass over or under a road surface, are increasingly implemented as conservation efforts because these corridors help maintain _____. (Choose the best answer) genetic drift sexual selection gene flow natural selection

gene flow

Biologists who study microevolution define evolution as a change in _____ within a population. (Choose the best answer) reproductive output gene frequencies food usage behavioral patterns

gene frequencies

A new island has arisen in the Pacific Ocean as a consequence of volcanic activity. Some of the first organisms to inhabit this new land include members of a spider species that can travel through the air using "balloons" made of light silk. The mainland population of these spiders is approximately 20% black, 15% grey, and 65% white. The new island population is 40% black, 15% grey and 45% white. The difference in color ratios between these two populations is an example of _____.

genetic drift

Since a phylogenetic tree is a hypothesis about evolutionary relationships, we want to use characters that are reliable indicators of common ancestry to build that tree. We use _____ characters in different organisms that are similar because they were inherited from a common ancestor that also had that character.

homologous

The feathers of modern birds are _____ with the feathers found in fossils such as Archeopteryx.

homologous

In out-group analysis, the traits of the group being studied, the _____ , are compared to the traits of a very close relative that clearly branched of earlier, the out-group.

in group

Genes that are found close to each other on the same chromosome are often ____.

linked

Which of the following processes can alter a gene pool? (Select all that apply) mutations natural selection non-random mating small population size gene flow

mutations natural selection non-random mating small population size gene flow

Most mutations in the human genome have ____ effects.

neutral

Microeveolution occurs at the _____ level. (Choose the best answer) cellular population community individual

population

Using the Hardy-Weinberg equation, you can determine all the allele and genotype frequencies in a population given the frequency of the _____ , for any trait determined by a single gene pair with a dominant allele and a recessive allele. (Choose the best answer) recessive phenotype random changes in DNA dominant phenotype all of the possible answers

recessive phenotype

Sex _____ genes, functioning as an important source of genetic variation in a population.

recombines

All of the variation we see in the living world is due to heritability, _____, and time.

selection

Match the type of sexual selection with its proper description. Intersexual Intrasexual

selection where females choose their mates selection where males compete with each other for reproductive rights

Endler's experiments with guppy populations sought to demonstrate _____ in response to predation.

sexual selection

Recombination is the ___ of genes during sexual reproduction.

shuffling

A derived character that is shared by clade members is called a _____.

synapomorphy

In a Hardy-Weinberg equilibrium, involving 2 alleles, p2+2pq+q2=1.

true