Biology - Exam Questions

If a population is in Hardy-Weinberg equilibrium and the frequency of the recessive allele is 0.8. What is q?

0.8

How many monophyletic groups are contained in this phylogenetic tree?

11

What is the ploidy of the following structures: gametophyte, sporangium, spore, sporophyte

1n, 2n, 1n, 2n

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

In the phylogenetic trees above, numbers represent species, and the same species are shown in both trees. Which two species are represented as sister species in Tree 2, but not shown as sister species in Tree 1?

3 and 4

If a randomly-mating population of ladybugs has 36 red individuals, 48 pink individuals, and 16 white individuals, then what is the percentage of the recessive allele that is responsible for the white phenotype in this population?

40%

In Caucasian humans, hair straightness or curliness is thought to be governed by a single pair of alleles showing incomplete dominance. Individuals with straight hair are homozygous for the H allele, while those with curly hair are homozygous for the h allele. In a population with 1,000 individuals where 490 have straight hair, 160 had curly hair, and 350 had wavy hair. We cannot assume this population is in Hardy-Weinberg equilibrium. Calculate the percent of individuals that express the dominant allele, H:

84%

Which of the following is the BEST example of microevolution?

Antibiotics that once killed all strains of the Escherichia coli bacteria cannot now kill several resistant strains

Given the phylogenetic tree shown below, which of the following two species (A-F) most recently shared a common ancestor?

CD

Which of these conditions are always true of populations evolving due to natural selection?Condition 1: The population must vary in traits that are heritable.Condition 2: Some heritable traits must increase reproductive success.Condition 3: Individuals pass on most traits that they acquire during their lifetime.

Conditions 1 and 2

Populations of guppies in quiet pools are separated by rapids, but occasionally, fish get swept downstream. They almost never are able to swim upstream through the rapids. What is the most likely result?

Downstream fish populations will become more genetically diverse

In Caucasian humans, hair straightness or curliness is thought to be governed by a single pair of alleles showing incomplete dominance. Individuals with straight hair are homozygous for the H allele, while those with curly hair are homozygous for the h allele. In a population with 1,000 individuals where 490 have straight hair, 160 had curly hair, and 250 had wavy hair. This population appears to be in Hardy-Weinberg equilibrium?

False

Which of the following statements about common features of chordates is true? I. The dorsal, hollow nerve cord is part of the chordate central nervous system II. In vertebrate fishes, the pharyngeal slits become the gill arches III. Humans are not chordates because they do not have a notochord IV. The notochord above the nerve chord

I & II

The wing of a grasshopper, the wing of a bird and the wing of a bat are ____________________ traits: I - analogous II - homologous III - vestigial IV - convergent V - divergent

I and IV

Fossils allow the scientific community _________________. I - the ability to study/view extinct organisms II - the ability to connect phylogenies of extinct organisms to extant organisms III - the ability to date extinct organisms IV - the ability to actually witness the next paradigm shift in terms of fossil analysis prior to the onset of technological advancement

I, II and III

Rules/principles of the Biological Species Concept include: I - A species can interbreed II - A species will interbreed III - A species will not produce viable offspring IV - A species will choose not interbreed with other species V - A species will have gene flow between populations

I, II, IV, V

In a certain randomly-mating population, there is also no mutation, no migration, no non-random mating, no natural selection, and the population is infinitely large. In terms of Hardy-Weinberg population genetics, this population would allow for or contain: I - No microevolution II - No change in Hardy-Weinberg "p" and "q" values III - A population geneticist to interconvert between the two Hardy-Weinberg formulas and know that they had numbers that were 100% correct IV - An interconversion or exact analysis from microevolution of a gene to all macroevolution effects within a particular environment V - Allow for a population geneticist to conclude the population was currently out of Hardy-Weinberg equilibrium at that time

I, II, and III

Which of the three viruses shown in the figures would you expect to infect bacteria?

III only

What is the correct order for the stages of a general viral infection/life cycle, from earliest to latest stages? I. Replication II. Assembly III. Attachment IV. Egress V. Entry

III, V, I, II, IV

Which of the following DOES NOT describe SARS-CoV-2?

Its DNA is replicated in the host

The peppered moth provides a well-known example of natural selection. The light-colored form of the moth was predominant in England before the Industrial Revolution. In the mid-19th century, a dark-colored form appeared. The difference is produced by a dominant allele of one gene. By about 1900, approximately 90% of the moths around industrial areas were dark colored, whereas light-colored moths were still abundant elsewhere. Apparently, birds could readily find the light moths against the soot-darkened background in industrial areas and, therefore, were eating more light moths. Recently, use of cleaner fuels has greatly reduced soot in the landscape, and the dark-colored moths have been disappearing as the two groups still interbreed. Should the two forms of moths be considered separate species?

No; they can still interbreed.

Which of the following best describes the physical relationship of the partners involved in lichens?

Photosynthetic cells are surrounded by fungal hyphae

For the processes of speciation to result in a new species forming from two population, what must occur?

Some type of reproductive barrier must arise between the populations

The following phylogeny shows six living species (a-f) and five ancestral (now extinct) species (1-5). If the phylogeny had been developed on the basis of similarities in bone structure, which of the following predictions would you make in terms of the structure of a particular enzyme?

The enzymes of species b and c are more similar to ancestor #4 than ancestor #2

If a population is out of Hardy-Weinberg equilibrium:

Then there is microevolution taking place.

Which of the following is characteristic of ciliates?

They are often multinucleate

In the ocean, on either side of the Isthmus of Panama, are thirty species of snapping shrimp; some are shallow-water species, others are adapted to deep water. There are fifteen species on the Pacific side and fifteen different species on the Atlantic side. The Isthmus of Panama started rising about ten million years ago. The oceans were completely separated by the isthmus about three million years ago.In the following figure, the isthmus separates the Pacific Ocean on the left (side A) from the Atlantic Ocean on the right (side B). The seawater on either side of the isthmus is separated into five depth habitats (1-5), with 1 being the shallowest. Why should deepwater shrimp on different sides of the isthmus have diverged from each other earlier than shallow-water shrimp?

They have been geographically isolated from each other for a longer time

Why are adaptations such as floral color, scent, and nectar advantageous to a flowering plant (in terms of individual fitness)?

They result in successful delivery of pollen to a potential mate with the least cost of energy to the individual plant

Place the following groups of organisms in correct order from smallest to largest in average size:

Viruses - Prokaryotes - Protists - Fungi

Which of the following descriptions correctly identifies the main structural differences between viruses with envelopes and viruses without envelopes?

Viruses with envelopes have a phospholipid membrane outside their capsid, whereas viruses without envelopes do not have a phospholipid membrane.

The figure above shows the distribution of pocket-mouse coat colors in several Arizona populations found either on light-colored granite substrate or on dark volcanic rock (dark substrate). The Melanocortin-1 receptor (Mc1r) alleles, D and d, differ by four amino acids. Mice with DD and Dd genotypes have dark coats, whereas mice with the dd genotype are light colored. What sort of genotype frequencies might you expect to find in the Xmas, West, and O'Neill populations?

Xmas: high dd frequency, West: high DD frequency, O'Neill: high Dd frequency

Which of the following characteristics is typical of the lytic cycle of a bacteriophage?

a large number of phages are released at a time

Which of the following is NOT a major difference between bryophytes and ALL other land plant phyla?

absence vs. presence of xylem and phloem

Looking under the microscope at some algae, you can see materials streaming through the cytoplasm in a coordinated manner. The small subcellular components most likely directly responsible for the movement are

actin filaments and myosin

Which of the following represent functions of the bacterial capsule?

all of these functions

Brown algae

alternation of generations

What is thought to be the origin of mitochondria of eukaryotic cells?

an aerobic heterotrophic prokaryote

The adaptive advantage associated with the filamentous nature of fungal mycelia is primarily related to _____.

an extensive surface area well suited for invasive growth and absorptive nutrition

Which of the following pairs of protists and their ecological roles are correctly matched?

apicomplexans - parasites of animals

In all plant life cycles, the sporophytes

are diploid plants that produce haploid spores

When natural selection is at work, the individuals with higher relative fitness are those who, compared to others in their population,

are leaving more viable offspring to the next generation

Bryophytes -

are more similar to ancestral green algae than vascular plants are

As humans select for and against various plant/fruit characteristics, the term "GMO" or, genetically modified organism is used in the press and various science publications. These scenarios are often times examples of - selection.

artificial

An entomologist studying insects in Texas found that there are five species of beetles known as fireflies present in the state. All of the species live in similar habitats and overlap geographically. All of the firefly species are able to flash their bioluminescence to attract mates, however they all have different flashing patterns. What is the most likely reproductice barrier that keeps these species from interbreeding?

behavioral isolation

planaria

bilateral symmetry

squid

bilateral symmetry

The outermost layer of a virion fulfills which of the following functions of the virus

both protection and recognition

The predatory bacterium Bdellovibrio bacteriophorus drills into a prey bacterium and, once inside, digests it. In an attack upon a gram-negative bacterium that has a slimy cell covering, what is the correct sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm?

capsule, lipopolysaccharide membrane, peptidoglycan, phospholipid membrane

Genetic drift produces variation for evolution when -

chance events in small populations cause allele frequencies to fluctuate unpredictably

Sponges are called "basal metazoans" because their phylogenetic position is closest to the common ancestor of all animals. What feature of sponges is visible evidence of the ancestral relationship?

choanocytes

Which of the following is the best modern definition of evolution?

descent with modification

Which of the following organisms is an autotroph

diatoms

In many bird species, those pairs that breed earlier in the season have higher reproductive success than those that breed later. Breeding date is known to be heritable and evolving to an earlier date. This is most probably an example of:

directional selection

The function of the heterocyst found in some cyanobacteria is to

fix atmospheric nitrogen

A porous test (shell) of calcium carbonate, through which pseudopodia protude, is characteristic of

foraminiferans

Immigration and successful mating of the new individuals can affect a population's allelic frequencies, as different alleles may be introduced by the migrant individuals. This exchange of alleles between conspecific (within the same species) populations is called:

gene flow

Ciliates

have micronuclei

Diatoms

have silica skeletons

Plasmogamy

heterokaryotic cells: cells with two haploid nuclei

All fungi are

heterotrophic

If a donkey and a - were to mate, the result would be a sterile -. This sterile organism would be an example of a non-viable hybrid. Thus making this an example of a - barrier to speciation.

horse; mule; post-zygotic

Many mammals have skins and mucous membranes that are sensitive to phenolic secretions of plants like poison oak (Rhus). These secondary compounds are primarily adaptations that _____.

inhibit herbivory

Trypanosoma

intercellular parasite

The process of metamorphosis transforms a - into a -

larva; sexually mature adult

Organisms that belong to different populations

live in geographically separate locations

Genetic variation -

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

Some fungal species live in plants, receiving nutrients from the plant, and kill herbivores that feed on the plant. What type of relationship does this fungus have with its host?

mutualistic

Arrange the following in order from largest to smallest, assuming they all come from the same fungus

mycelium, mushroom, hyphae, spore

The spice finch is a bird native to Asia. These birds have two behaviors for foraging, finding food for themselves (producers) or joining other birds who have already found food (scroungers). When producers are most common, scroungers will have the highest fitness. When scroungers become more common, producers will have the highest fitness. What type of selection is this an example of?

negative frequency-dependent selection

Which of these phyla is not in the lophotrochozoan clade?

nematoda

You are studying a new organism. If you find -, you are certain that it belongs in the Animal Kingdom.

neurons

What is an allele?

one of a number of alternate forms of DNA sequence at a particular genetic locus

On the phylogenetic tree, animals are most closely related to

opisthokonts called choanoflagellates

25 of the 33 species of bats in Texas belong to the family Vespertilionidae. All 25 of these bats species must belong to the same -

order

The cell found in bone that breaks it down is called

osteoclast

You would most likely find a parasite with a complex life cycle in a member of phylum

platyhelminthes

Systematists try to avoid __________________ groupings given that this type of grouping typically implies that modern phylogenetic genomic sequencingwill allow for taxonomic designates and cladistics to shift within a short period of time. Furthermore, this type of grouping often times does not help systematists to visually show evolutionarily significant relationships.

polyphyletic

The smallest biological units that can evolve are

populations

Digestive organs, circulatory system, and nerve cords are completely absent in

porifera

Dinoflagellates -

possess two flagella

Gastrulation is a process that

produces an endoderm germ layer

In prokaryotes, new mutations accumulate quickly in populations, while in eukaryotes, new mutations accumulate much more slowly. The primary reasons for this are -

prokaryotes have short generation times and large population sizes

Pinworms, hookworms, and Trichinella spiralis (which causes trichinosis) are all unsegmented ecdysozoan parasites in the same phylum. Therefore, they all have

pseudocoelom

jelly fish

radial symmetry

sea anenome

radial symmetry

n a hypothetical situation, the genes for sex pilus construction and for tetracycline (an antibiotic) resistance are located on the same plasmid within a particular bacterium. If this bacterium readily performs conjugation involving a copy of this plasmid, then the result should be the ________.

rapid spread of tetracycline resistance to other bacteria in that habitat

SARS-CoV-2 spreads via

respiratory droplets, aerosols or droplet nuclei, fomite

Retroviruses require the activity of ________ to complete their infection cycle.

reverse transcriptase

Currently, two of the living elephant species (X and Y) are placed in the genus Loxodonta and a third surviving species (Z) is placed in the genus Elephas. Assuming this classification reflects evolutionary relatedness, which of the following is the most accurate phylogenetic tree?

see image

Porgs are a species of sea-dwelling bird that are native to the planet Ahch-To. The birds are short with flat, beakless faces, and webbed feet. They have dense feathers with white coloration on their body and wings and gray to brown feathers on their wings. The males have orange feathers around their eyes. What is the most likely cause of sexual dimorphism in this species?

sexual selection

Reproductive isolation between two populations can result in

speciation

You are a researcher studying the diets of hawksbill sea turtles. You have the chance to study the stomach contents of a turtle killed by accident in a fishing net. You observe no fish bones in the stomach and no other recognizable food parts. You then examine the contents under the microscope and observe thousands of tiny, glassy, spikes (see above). What can you conclude that the turtle is eating?

sponges

In male peacocks, the males with very small tail feathers rarely attract females while the male peacocks with very large tail feathers are often predated upon by feline and canine predators. This would constitute - selection

stabilizing

Immediately after the island of Hawaii rose above the sea surface (somewhat less than one million years ago), the initial evolution of life on this new island should have been most strongly influenced by

the founder effect

All of the following are true about SARS-CoV-2 infection EXCEPT

the new virions stay within the host cell and do not leave

Which of the following is true at SARS-CoV-2?

the virus has a higher mutation rate than DNA viruses

Which of the following statements about scientific models is false:

they precisely predict what will happen given available information and reasonable assumptions

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily?

to serve as an outgroup

Which of the following is a major trend in land plant evolution?

trend toward a sporophyte-dominated life cycle

Where does meiosis occur in the pine life cycle?

within a megasporangium