GEN BIO II: FINAL EXAM

Blue flower color (B allele) is dominant to white (b allele). If a population of plants in Hardy-Weinberg equilibrium contains white flowers (bb) at a frequency of 0.04, what is the frequency of the blue flower allele (B)?

0.8 or 80%

What is the Hardy-Weinberg equation?

p²+2pq+q²=1

Which scenario best illustrates the process of natural selection?

A population of mosquitoes develops resistance to a pesticide

Molecular homologies indicate that living species evolved from a common ancestor or interrelated group of common ancestors.

True

English ivy (Hedera helix) and winter creeper (Euonymus fortunei) are not closely related, yet both have aerial rootlets that allow them to climb up and stick to bark on trees. What type of evolution is this?

Convergent

You are at the aquarium looking at a freshwater mammal tank and an adult manatee swims close to the glass. On his front flippers you see fingernails. What is a likely explanation for the presence of fingernails on a manatee?

They are vestigial structures.

What is the term that best describes a species that is naturally only found in one particular region of the earth?

endemic

Which of the examples below are polymorphic traits?

The A, B, and O blood types found in humans.

In the Hardy-Weinberg equation, p + q = _____, where p and q represent _____.

1, allele frequencies

Fundamental similarity due to descent from a common ancestor is called

homology

In _____ selection, individuals with intermediate phenotypes have the highest reproductive success.

stabilizing

While on a hike, you are lucky enough to see many tiger swallowtail butterflies. You observe that there are two types of the butterflies — a yellow type and a black type. What is the best explanation for this?

The tiger swallowtail butterfly has more than one allele for the gene that determines color.

The sickle-cell allele (HbS) is maintained in some human populations because heterozygotes are resistant to malaria. If malaria were completely eliminated by an effective vaccine, what would most likely happen to the HbS allele?

The frequency of HbS would decrease because it would not longer provide an advantage.

Your neighbor has been raising quail for decades. Every year, she chooses the biggest eggs to hatch for the next generation of birds. Now they lay really big eggs! What is this an example of?

Artificial selection

The allele for brown eyes is dominant over the allele for blue eyes. In a population of 15,000 individuals, 25% were found to have blue eyes. What is the frequency for the dominant allele?

p=.8

Darwin’s observation that offspring resemble their parents led him to conclude that the traits passed on to offspring are _____.

considered heritable

When observing the skeleton of a snake, you see the remains of hip and hind leg bones associated with four legged animals. These bones are called

vestigial structures

The allele for dimples (D) is dominant. In a random sample of 2,000 individuals, 1,745 individuals had no dimples. Determine the frequency of the dominant and recessive alleles in this population. How many individuals would be expected to be heterozygous for dimples?

255

Which of the following would most likely result in a bottleneck event?

A hurricane blows through a coastal swamp inhabited by an apple snail population. The hurricane drastically changed the hydrology of the swamp, killing 98% of the apple snails.

Intrasexual selection happens between members of the same sex as they compete for mates or territories.

True

When humans are developing in utero they have characteristics that are not found in the fully developed infant. Which type of homology does this typify?

Developmental

What is the term for similar traits that are inherited from a common ancestor?

homology

What is the most direct outcome of natural selection in a population?

Adaptions

If a population has the following genotype frequencies: AA=.32, Aa=.46, AA=.22

What is the total number of “A” alleles?

90

The scientist who recorded information above the natural world on the voyage of the Beagle and developed a theory that existing species have evolved from pre-existing species was _____.

Charles Darwin

Evolution is based on ___ and ___.

Genetic variation & natural selection

Broccoli is formed by overexaggerating the flower buds and stems of a wild mustard plant over the course of several generations. What is this an example of?

Artificial selection

Which word best describes changes that promote a populations survival and reproduction?

Adaptation

There is a population of frogs living in a pond, 25 are green, 25 are brown, 25 are yellow with green spots and 25 are all yellow. A drought occurred and 75% of the frogs dies, with the remaining frogs green and brown. After 25 generations the frogs still were green and brown, and yellow frogs never appeared int he population again. Which of the following best explains this phenomenon?

Bottleneck effect

Evolution, viewed on a small scale, as it related to changes in a single gene or allele frequency in a population over time, is called

microevolution

What phenomenon tends to increase genetic variation in a population?

Gene flow

The term evolution is used to describe

heritable changes in characteristics of a population from one generation to the next.

What phenomenon would violate the condition for Hardy-Weinberg equilibrium?

Migration of individuals between populations

Which type of selection is most likely to lead to an individual with a feature that makes them less likely to survive?

diversifying selection

A gene pool is

all the genes in a population.

Microevolution involves

changes in a population’s gene pool.

Male deer have large antlers that are used to challenge each other in fights for territory and females. The females of this group actively choose the strongest males. Which type of sexual selection is occurring with the deer population?

Both intersexual and intrasexual

Cacti in the deserts of southwestern North America and some euphorbs of the deserts of Africa have barrel-shaped stems, short-lived leaves, and spines, yet these two types of plants are from different evolutionary lineages. This is an example of

convergent evolution

In a population of 100 four-o’clock flowers there are 40 red-flowered plants (C^RC^R), 38 pink-flowered plants (C^RC^W), and 22 white-flowered plants (C^WC^W). What is the frequency of the C^W allele in this population?

0.41 or 41%

To analyze genetic variation in populations, we need to calculate allele frequencies. For the sake of calculating allele frequency for a diploid species, how many alleles are present for a single gene in each individual?

2

What mechanism leads to changes in allele frequencies due to random chance?

Genetic drift

Over generations in a population, traits seen in individuals with higher fitness values will

become more prevalent in the population.

In the Hardy-Weinberg equation, the genotype frequency of heterozygotes is represented by

2pq

Microevolution is the formation of new species or groups of species.

False

Which structure allows amoebae to move and capture food by extending part of their cytoplasm? (hint - fake foot)

Pseudopodia

What is the main component of most bacterial cell walls?

Peptidoglycan

A microorganism uses light to generate ATP but must obtain organic molecules from its environment as a carbon source. What is this organism classified as?

Photoheterotroph

Archaea, Bacteria, and Eukarya are:

domains

Some fungi obtain nutrients by trapping and digesting small soil organisms such as nematodes. These fungi are best described as:

Predatory fungi

Which of the following is NOT true of horizontal gene transfer?

It occurs when genes are transferred from parent to progeny.

The cell walls of most fungi are composed of

chitin

Bacteria that can grow with or without oxygen are called:

Facultative aerobes

Peptidoglycan is best described as:

A polysaccharide-protein complex that provides structural support in bacterial cell walls

Which of the following correctly lists the three major ecological types of protists?

Algae, Protozoa, Fungus-like protists

A fungus rapidly spreads across a piece of bread in a kitchen without producing fruiting bodies. Which reproductive strategy is most likely occurring?

Budding or reproduction of conidia

What feature allows many Archaea to survive in extreme environments?

Unique membrane lipids

Which group of bacteria produces oxygen as a result of photosynthesis?

Cyanobacteria

A pathogen is a parasitic microbe.

True

Members of the supergroup Amoebozoa are characterized by:

locomotion via pseudopodia

After a forest fire, bacteria and fungi begin breaking down dead trees and plant debris. What ecological role are these organisms performing?

Decomposers

Which structure helps some bacteria move across surfaces by twitching or gliding?

Pili

The algae are diverse in many ways, but one commonality is that they

all have photosynthetic pigments

An organism that must obtain organic molecules for carbon is a:

heterotroph

Horizontal gene transfer refers to:

Movement of genes from one species to another

Ergot produces a psychogenic compound related to LSD and is

a fungal disease of rye crops and other grasses.

A drug that inhibits peptidoglycan synthesis would most directly affect which type of organism?

Bacteria

Which defensive adaptation involves spear-shaped projectiles used to discourage predators?

Extrusomes

An obligate anaerobe is an organism that:

is poisoned by oxygen

Which of the following statements is NOT true of Gram-positive bacteria?

They possess an outer membrane outside the peptidoglycan layer.

Which of the following statements does NOT describe a function of the cell walls of bacteria?

They prevent horizontal gene transfer.

A bacterium grows well in the presence of oxygen but can also survive when oxygen is removed from the environment. This organism is best classified as a:

facultative aerobe

Two bacterial species living in the same environments exchange genetic material, resulting in the rapid spread of antibiotic resistance. What mechanism best explains this scenario?

Horizontal gene transfer

Which oft he following is NOT a way that bacteria benefit humans?

formation of biofilms on medical implants

Phagotrophy (phagocytosis) is:

the capture and ingestion of food particles by a cell

Which structure do ciliates use for movement?

Cilia

The super group, Stramenophiles are named for their distinctive:

Strawlike hairs on flagella

All known protists can reproduce asexually.

True

Which of the following statements DOES NOT characterize decomposers?

They synthesize organic molecules using sunlight.

The atmosphere and seas of the early Earth lacked oxygen. What kind of organisms could NOT have lived under those conditions?

obligate aerobes

Some protists bear a small number of external cellular structures that facilitate swimming by repeatedly bending and straightening. These protists are informally known as:

flagellates

Which of the following terms DOES NOT describe a basic type of protistan nutrition?

eutrophic

Which of the following describe sexual reproductive processes in fungi?

fusion of different, but compatible hyphal branches

A fungus is growing on a piece of fallen wood. Its hyphae extend deep into the substrate, secreting enzymes and absorbing nutrients. Which feature most directly allows this efficient absorption?

Extensive branching of hyphae

Organisms that live in very high salt environments are called:

Halophiles

Which one of the following is NOT used by protists for protection against predators?

shooting acids

In alternation of generations, the diploid multicellular stage that produces spores is the:

Sporophyte

Protists is a kingdom that falls under the Archaea domain.

False

Binary fission is best described as:

Asexual reproduction by splitting into two cells

A researcher studying a toxic waste site found a previously-unknown microbe. The organism is colorless, unicellular, and surrounded by a cell wall composed of proteins. The cell membrane contains isoprene chains and phospholipids with either bonds. This organism is most likely to be what type of microbe?

Archaea

What is the source of energy for the synthesis of organic molecules in a photoautotroph?

light

Which characteristic is shared by both Archaea and Bacteria?

They lack a nucleus

The proteobacterium Rhizobium lives in a close association with legume roots, providing a source of nitrogen for the plant. In return, the plant provides Rhizobium with food produced by photosynthesis. In this relationship, Rhizobium is an example of a

mutalist

Some microbes secrete small molecules that induce other microbes to settle nearby. When a certain number of individuals have assembled, the chemical signal is strong enough to induce the aggregation to respond collectively to stimuli. This process is called

quorum sensing

Archaea that live in unusual habitats with high temperatures, salt, acid, or methane are called extremophiles.

True

What would happen if the cortical reaction proceeded before the acrosomal reaction was complete?

Fertilization would not occur.

Which organ is responsible for the synthesis of ketones from fatty acids?

liver

“Glycogenolysis” refers to the state where

glucose levels are increased in the blood through the breakdown of glycogen.

How do endotherms and ectotherms derive most of their body heat?

Ectotherms derive most of their body heat through their environment, while endotherms derive most of their body heat through metabolic processes.

Sexual reproduction

increases genetic variation

Once an egg has been fertilized, what event is crucial for preventing additional sperm from inserting DNA into the egg?

the cortical reaction