CBEN 120 Test 2

I. Biological species are defined by reproductive isolation III. The biological species is the largest unit of population in which successful interbreeding is possible

Which of the following statements about species, as defined by the biological species concept, are correct?

The fossil record includes more organisms that were abundant, or lived for long periods on Earth, than it is with those that lived for short periods of time and then became extinct

Which of the following statements about the fossil record is correct?

morphological

You are an undergraduate student working with a graduate student in an entomology lab, and she presents you with a box of preserved grasshoppers of various species that are new to science and have not yet been described... Which species concept will you have to use?

The group moved to Estes Park will undergo a series of adaptations to survive

A large community of rattlesnakes, from EL Paso, Texas is separated into two groups. One group is taken 46 miles northwest to Las Cruces, New Mexico. The other group goes 712 miles north to Estes Park, Colorado. Which of the following statements is most accurate?

silent mutation

A mutation that is neither harmful nor beneficial is termed a

a character that originated in an ancestor of two taxa

A shared ancestral character is

Their genomes should be more similar to each other than are the genomes of the five tree finch species.

About 13 different species of finches inhabit the Galapagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the 13 species are currently classified among three genera. The first lineage to diverge was the warbler finch. Next was the vegetarian finch followed by five tree finch species and six ground finch species. If the 6 ground finch species have evolved most recently, which is the most logical prediction?

allows new species to occupy different habitats

Adaptive radiation

the bacteria's unchanging environment

An article in the NYT stated the following: "Scientists have discovered microorganisms living beneath the ocean floor that appear to have not evolved for more than two billion years, a finding that nonetheless may support the theory of evolution." The lack of evolution could be caused by

similar; common

Analogous features share ______ function but not _______ ancestry.

Characteristics acquired during an organism's life are not passed on through genes

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception?

in two populations of a species over as little as one generation, even if they are not reproductively, biologically, or geographically isolated

Evolution of a new species can occur

54%

If on average, 46% of the loci in a species' gene pool are heterozygous, then the average homozygosity of the species should be?

D and F

If organisms A, B, and C belong to the same class but different orders, and it organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?

22,900

If the half-life of carbon-14 is about 5,730 years, then a fossil that has 1/16th the normal proportion of carbon-14 to carbon-12 should be about how many years old?

genetic drift and the founder effect

If the original finches that flew over the Galapagos Islands from South America had already been genetically different from the parental population of South American finches, even before adapting to the Galapagos, this would have been an example of

0.09

In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele?

31%

In a population of 200 seagulls, dark brown feathers are dominant to having only white feathers. If 160 of the 200 seagulls have brown feathers, what is the frequency of seagulls that are homozygous dominant?

domain

In addition to naming species, Linnaeus also grouped species into a hierarchy of increasingly inclusive categories. The largest category that would include closely related species is the

continents may come back together during the next few hundred million years, forming new mountain ranges and larger continents

Learning from the history about plate-tectonics on Earth, scientists now predict that

when reproductive barriers, either pre- or post- zygotic, genetically isolate species, even in the presence of some gene flow between the two populations

Macroevolution occurs

species selection

Many species of snakes lay eggs. However, in the forests of northern Minnesota where growing seasons are short, only live-bearing snake species are present. This trend toward species that perform live birth in a particular environment is an example of

individuals adapt to their environments and thereby evolve

Natural selection is based on all of the following except

2%

Phenylketonuria (PKU) is a birth defect... frequency of individuals born in a population with PKU is q^2. There is one PKU (q^2) per 10,000 births. The frequency of the recessive allele is q = 0.01. What is the frequency of carries (2pq) in this population?

1. sympatric species 2. prezygotic isolation

Rocky mountain juniper and one-seeded juniper have overlapping ranges. If pollen grains from one species are unable to germinate and make pollen tubes on female ovules of the other species, then which of these terms are applicable?

sympatric

The form of speciation that requires the emergence of a reproductive barrier that isolates a subset of a population from the remainder of the population in the same area is

the postzygotic barrier, reduced hybrid viability

Two species of frogs belonging to the same genus occasionally mate, but the offspring fail to develop and hatch. What is the mechanism for keeping the two frog species separate?

genetic variation among individuals

Which of the following must exist in a population before natural selection can act upon that population?

Mutations occur at random; natural selection can preserve and distribute beneficial mutations

What is true of natural selection?

homeotic genes

What type of genes control how flower petals are arranged or where a set of wings on a bird will develop?

shared derived characters

When using a cladistic approach to systematics, which of the following is considered most important for classification?

addition of oxygen to the atmosphere

Which event stimulated the rapid development of eukaryotes?

India was a separate continent until 45 million years ago

Which factor most likely caused animals and plants in India to differ greatly from species in nearby Southeast Asia?

increased gene flow

Which mechanism would reverse speciation?

bones in the bat wing and bones in the human forelimb

Which of the following are the best examples of homologous structures?

duplication

Which of the following describes a mechanism for generating more genes?

a farmer cultivating sweet watermelons

Which of the following is an example of artificial selection?

The common ancestor represented by the rightmost branch point existed more recently in time than the common ancestors represented at branch points located to the left

Which of the following is true of all horizontally oriented phylogenetic trees, in which time advances to the right?