Biology 1407 Test 1

More species tend to be found in regions subdivided by rivers, canyons, mountains, or other human-induced barriers because of

. Allopatric speciation.

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?

0.09

Currently, two extant ( present day) elephant species (X and Y) are placed in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which of the following statements is true?

Species X and Y share a greater number of chromosomal homologies than with species Z.

Evolution is best define as which of the following

a change in the genetic composition of a population from generation to generation

Hox genes are a group of related genes that

control the body plan of an embryo and are conserved across many taxonomic groups

Two plant species live in the same biome but on different continents. Although the two species are not at all closely related, they may appear quite similar as a result of

convergent evolution

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

domain.

which of the following describes the mechanism of genes for generating more genes?

duplication

A moderate-size lake in the American Midwest suddenly has succumbed to an algal bloom. What is the likely cause of eutrophication in this lake?

excessive farm fertilizer runoff during a heavy rainfall

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that

island forms and mainland forms descended from common ancestors.

Aquatic primary productivity is most limited by which of the following?

light and nutrient availability

In the figure above, which similarly inclusive taxon is represented as descending from the same common ancestor as Taxidea?

lutra

A cow's herbivorous diet indicates that it is a(n)

primary consumer.

To recycle nutrients, an ecosystem must have, at a minimum,

producers and decomposers.

The major role of detritivores in ecosystems is to

recycle chemical nutrients to a form capable of being used by autotrophs.

Analogous features such as the wings of a bird and those of insectis share ________ function but not ________ ancestry.

similar,common

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were caused by MRSA. How can this best be explained?

some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

Subtraction of which of the following will convert gross primary productivity into net primary productivity?

the energy used by photoautrophs in respiration

Photosynthetic organisms are unique to most ecosystems because they

use light energy to synthesize organic matter from inorganic matter

When evolution occurred on the Galápagos Islands, the finch beaks

varied in size across the population and sometimes conferred benefits in feeding, survivorship, and reproduction that were passed down to surviving offspring

What is a population in biology?

when a group of individuals of the same species live in the same area and interbreed

A species is represented by individuals that form a populations

whose members have the ability to interbreed and produce viable, fertile offsprings

Which of Darwin's ideas had the strongest connection to Darwin having read Malthus's essay on human population growth?

1. the struggle for existence

Energy transfer between trophic levels is typically only 10% efficient. Approximately how many kilograms of secondary consumer biomass can be supported by a field plot containing 1,000 kg of plant material?

10

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship.

2->4->1->3

7) What are adaptations?

A) inherited characteristics of organisms that enhance their survival and reproduction in specific environments

Speciation that occurs when continents move and cause geographic barriers to gene flow and reproduction between populations of species would be termed which of the following?

Allopatric speciation.

Which of these ecosystems has the highest net primary productivity per square meter annually?

Amazon rain forest

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

Bones in the batwing and bones in the human forelimb.

Which statement most accurately describes how matter and energy are used in ecosystems?

Energy flows through ecosystems; matter cycles within and through ecosystems.

From the list below, select the correct format for the binomial (scientific name) of the species the monarch butterfly.

Danaus plexippus.

Which of the following best explains the difference between Lamarck's and Darwin's mechanisms for evolution?

Darwin's theory corroborates with current knowledge of inherited traits.

Why does a vegetarian leave a smaller ecological footprint than a person who eats meat?

Eating meat is an inefficient way of acquiring photosynthetic productivity.

Natural selection is based on all of the following except

Individuals adapt to their environments and, thereby, evolve.

Which of the following is true of microevolution?

It is the kind of evolution that can change the relative abundance of a particular allele in a gene pool over the course of generations.

Which of the following is correct about genetic variation?

It must be present in a population before natural selection can act upon the population.

The original source of all genetic variation is __________.

Mutations

Identify the statement that describes the imperfection natural selection.

Natural selection is generally limited to modifying structures that were present in previous generations and in previous species.

If the sun were to suddenly stop providing energy to Earth, most ecosystems would vanish. Which of the following ecosystems would likely survive the longest after this hypothetical disaster?

Pacific deep-sea vent ecosystem

Recent research investigating variation in human height have found that a variety of genes at different loci, as well as early nutrition, especially that of the mother during gestation (the period of time during development of a fetus) and childhood years, influence height. Given this information, which of the following is correct?

Phenotypes are usually the result of a combination of genes as influenced by the environment

Why don't similar genotypes always produce the same phenotype?

Phenotypes can vary depending upon the environment

Why did dark-colored rock pocket mice first appear in a population of light-colored rock pocket mice?

They have a genetic mutation that affects their fur color.

Mountains also have an unmatched power to drive human evolution. Starting tens of thousands of years ago, people moved to high altitudes, and there they experienced natural selection that has reworked their biology. In Tibet, for example, people have broader arteries and capillaries. In the Andes, they can dissolve more oxygen into their blood. These different traits of people who live in high altitudes illustrate

adaptive evolution

Which event stimulated the rapid development of eukaryotes?

addition of oxygen to atmosphere

You discover a fossil with feathers on forelimbs, short hind limbs, and teeth. You conclude that this organism appears early on a phylogenetic tree for which group of organisms?

birds

Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing

gene flow

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

heterozygotes have two alleles

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that __________.

humans and chimpanzees share a relatively recent common ancestor.

Which life form has been present on Earth the longest?

microbes such as bacteria

Which of the following criteria used in classification, such as Linnaeus used, is the most easily evaluated by the observer

morpholgy