Biology Practice Exam 1 (Ch.22-25)

The Ecological species concept ________.

View species in terms of its ecological niche

Which conditions are always true of populations evolving due to natural selection?

-The population must vary in traits that are heritable. -Some heritable traits must increase reproductive success.

How many genes are required to change in order for speciation to occur?

-single genes -multiple genes

In peas, a gene controls flower color such that R=purple and r=white. In an isolated pea patch there are 36 purple- flowering plants and 64 white-flowering plants. Assuming Hardy-Winberg equilibrium, what is the value of q in this population?

0.80

In a Hardy-Weinburg population with two alleles, A and a, that are in equilibrium, the frequency of allele a is 0.1 What is the frequency of individuals with AA genotype?

0.81

You sample a population of butterflies and find that 56% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population?

Allele frequency cannot be determined from this information

There is still some controversy among biologists about where Neanderthals should be placed within the same species as modern humans or into a separate species of their own. Most DNA sequence data analyzed so far indicate that there was probably little or no gene flow between Neanderthals and Homo sapiens. Which species concept is most applicable in this example.

Biological

Which of the various species concepts distinguishes two species based on degree of genetic exchange between their gene pools?

Biological

Modern definition of Evolution ?

Descent with Modification

Which best explains intrasexual selection?

Direct competition among individuals of one sex for mates of the opposite sex.

Which statement about the beak size of finches on the Island of Daphne Major during prolonged drought is true?

Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted.

__________ had the most influence on the evolution of life on Hawaii after it rose above sea surface.

Founder Effect

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

India was a separate continent until forty-five million years ago.

What must be true of any organ described as vestigial?

It must be homologous to some feature in an ancestor.

In the mid-1900s, the soviet geneticist Lysenko believed that his winter wheat plants, exposed to increasingly colder temperatures, would eventually give rise to more cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with ideas of __________.

Lamarck

Which of the following is not related to balancing selection?

Movement of alleles among populations

Adaptations have arisen by _______.

Natural Selection

The largest unit within which gene flow can readily occur is _______.

Species

Currently, two extant elephant species (x and y) are classified in the genus "Loxodanta", and a third species (z) is placed in the genus "Elapses". Thus, what is true?

Species x an y share a greater number of homologies with each other than either dos with species z.

Heterozygote advantage can result from

Stabilizing or directional selection

According to the morphological species concept, a species will be defined by ________.

Structural features within a species

Which strata layer is the youngest?

Top

Which of the following is not a type of data that documents the pattern of evolution?

all are correct examples that document evolution

A population of organisms will not evolve if ______.

all individual variation is due only to environmental factors

The cow "Bos primigenius" (which is bred for meat and milk) has a smaller brain and larger eyes than closely related wild species of ungulates. These traits most likely arose by _______.

artificial selection, because changes in in these traits co-occured with human selection for high milk output and high muscle content.

Sugar Gliders and flying squirrels have similar characteristics and will be found on different continents. This is an example of :

convergent evolution

Which of the following did chloroplasts derive from?

cyanobacterium

Microevolution is _________.

defined as a change in allele or gene frequency over the course of many generations.

If there is no gene flow, the curve shifts to the left or to the right,and the population size consequently increases over successive generations, which of the following is most likely occurring?

directional selection

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it ________.

dismissed the idea that species are constant and emphasized the importance of variation and change in populations.

An earthquake decimates the ground-squirrel population, killing 98% of the squirrels. The surviving population happens to have broader stripes, on average, than the initial population. If broadness of stripes is genetically determined, what effect has the ground-squirrel population experienced during the earthquake?

genetic bottleneck

Unlike Earth today, early Earth _______.

had an atmosphere rich in gases released from volcanic eruptions

In the formula for determining population's genotype frequencies, the "pq" in the term 2pq is necessary because ________.

heterozygotes have 2 alleles

A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the birds. Which of these events is most likely to occur to the birds beaks?

increased variation in beak size and shape over time

You are confronted with a box of preserved grasshoppers of various species that are new to science and haven't been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use?

morphological

Mutation is the only evolutionary mechanism that _____.

none of the above