Superbugs and Antibiotics
If thymine (T) makes up 20% of the bases in a DNA double helix, what percentage of the bases is guanine (G)?
30%
As habitats change, populations of northern pine trees that were once separated can now exchange pollen. This exchange of genes between populations is allowing the previously isolated gene pools to mix. The mechanism of evolution is
gene flow
Insecticide resistance among mosquitos is spreading around the world after mutations that originate in one population are spread to other populations through matings. The mechanism of evolution is
gene flow
In a population with brown and green alleles for color, genetic drift
has more effect on the evolution of a small population.
The _______ is a viral life cycle in which the virus inserts its genome into the genome of its host, where it may remain dormant for long periods.
lysogenic cycle
The ________ is a viral life cycle that results in bursting of the host cell.
lytic cycle
What is the most likely explanation for the changes in gene copies?
mutation
The ______ is the most prominent membrane-bound organelle in eukaryotic cells, and it houses most of a cell's DNA.
nucleus
A ________ is an agent in the environment that has the potential to cause disease.
pathogen
A _______ is a viral genome that has inserted itself into the genome of its host.
prophage
Some researchers have proposed that the human population was reduced to fewer than 10,000 individuals as a result of a catastrophic event that occurred about 50,000 years ago, and that all modern humans are descendants of this small population. If this proposal is true, it would be an example of __________.
the bottleneck effect
Which of the following can be found in bacteria, but not viruses?
Cell membrane
Which of the following best defines microevolution?
Changes in genes within a population over time
Place the following steps of DNA replication in the proper order: DNA fragments are fused together; double helix is pulled apart; new strands of DNA are synthesized.
Double helix is pulled apart, new strands of DNA are synthesized, and DNA fragments are fused together
______ defenses are always at the ready and are the same whether a particular infectious agent has been encountered before or not.
External
Carbon dioxide diffuses out of the alveoli and into the pulmonary capillaries, while oxygen diffuses out of the pulmonary capillaries and into the alveolar sacs.
False
There are many organs and glands of the endocrine system, but which one is the master controller?
Hypothalamus
While working as a microbiologist, you discover a new species of Clostridium. Which of the following is true?
It is most likely harmless.
Which of the following is true regarding the 2014-2015 measles outbreak in the U.S.?
It occurred throughout the entire United States.
Why is the enzyme lactase necessary to digest dairy products?
Lactase breaks down lactose into smaller molecules that can be absorbed by the cells that line the small intestine.
Most people are lactose intolerant as adults, but nearly everyone produces sufficient lactase as an infant. However, in some cases, genetic mutations can occur that make an infant lactose intolerant. From an evolutionary perspective -- over thousands of years -- why would lactose intolerance in infants be very rare in the population?
Lactose intolerant infants could not digest breast milk and therefore usually died, never having the chance to pass the mutation on to their children.
If the expectations of the WHO are met, which of the following will occur?
Many other countries will be malaria free by 2020.
Some viral diseases are dangerous only when a person is infected for the first time; subsequent infections produce only mild symptoms or go entirely unnoticed. This pattern can be explained by the action of _____.
Memory cells
What is the original source of variation that natural selection can act upon?
Mutation
______ describes the process of engulfing and destroying a foreign particle.
Phagocytosis
Which of these sub-cellular structures is found in both eukaryotes and prokaryotes?
Ribosomes
Compare sickle cell disease and malaria.
Sickle cell disease and malaria are both potentially lethal diseases.
A virus enters your system and successfully invades and infects a cell. At this point it is vulnerable to recognition or attack by _____.
T cells
If one polynucleutide strand of DNA has ACTTGACTAGCTA as its sequence of bases, what would be the sequence of bases on the opposite strand?
TGAACTGATCGAT
Following an injury to your hand, the injured area appears red and swollen. It feels painful and warm to the touch. What is the cause of these symptoms?
The Inflammatory Response
Although most biologists do not consider viruses to be alive, viruses do share some characteristics with living things. Which of the following is the requirement for life that viruses lack?
The ability to reproduce on their own
Which part of a nucleotide molecule in DNA encodes genetic information?
The base
You are prescribed antibiotics for strep throat. Which of the following is true?
The drug will kill many kinds of bacteria.
A drug that inhibits DNA ligase but not DNA polymerase is added to a cell. Explain how DNA replication would be affected as a result of the drug.
The new DNA fragments would not be fused together and the backbone of the DNA would be incomplete
A new case of malaria is diagnosed in Paraguay. Which of the following is true?
The patient can receive free care at a public or private clinic.
If a person has two normal copies of the hemoglobin allele, which statements are true?
The person is susceptible to malaria. The person is homozygous at the hemoglobin locus.
Overall, a molecule of DNA has a negative charge. Which component of DNA gives it this charge?
The phosphate group
Which of the following is the best example of a species that is locally extinct?
The red-breasted nuthatch, missing from part of its range.
How do lactase supplements help people who are lactose intolerant?
The supplements provide the enzyme that breaks down the lactose in dairy products.
Which of the following statements about viruses is FALSE?
The widespread use of antibiotics has led to resistant strains of viruses.
You are a herpetologist studying how milk snakes in Minnesota respond to climate change. Which of the following would be a morphological change?
They are increasing in average length.
Choose the defining characteristic of all arteries.
They only carry blood away from the heart.
Lactose intolerance in infants is more common in the population today than it was a hundred years ago. Why?
Today there are alternatives to breast milk, such as lactose-free formula and soy milk, so lactose intolerant infants can survive.
Which of the following conditions are required for evolution to occur?
Traits must be heritable. Resources in the environment must be limited. Individuals within a population must vary in their ability to compete for resources.
A person vaccinated for measles can get the disease, though it is not likely.
True
True or False: Protein-coding genes make up far less of the human genome than noncoding DNA.
True
______ are not alive because they are not made of cells and require a host cell for reproduction.
Viruses
You are a pediatrician in Southern California. Who are you likely to have the hardest time convincing to have their child vaccinated?
Wealthy parents that lead an all-natural lifestyle.
In the immune response, the end goal is to disable or kill pathogens that invade the body. But first, antibody proteins or proteins in immune cell membranes must recognize and bind to invaders. This is a challenge, given the vast diversity of pathogens that can infect us. To meet this challenge, immune proteins _____.
are diverse: each immune protein can bind to only one or a few pathogens, but immune proteins are tremendously diverse, so the system is likely to possess a "match" to nearly any pathogen
Which of the following is an orphan gene?
A gene found only in the southern two-toed sloth
Which of the following places is likely to have the highest level of local extinction?
A tropical forest in Guyana.
______ describes a set of defenses that is customized to each infectious agent, providing a stronger response when an agent has been encountered before.
Adaptive Immunity
Why should we not view lactose intolerance as a disease in adult humans?
Adult humans did not consume dairy products until fairly recently in our evolutionary history.
What is the condition called when your body's immune system overreacts to an otherwise harmless foreign particle?
Allergy
Which of the following correctly describes what the video referred to as a "microbial cure"?
Antibiotics are used to kill all of the infectious bacteria in a person.
Over time, bacteria have become increasingly resistant to antibiotics. Which of the following best explains this in terms of natural selection?
Bacteria that happen to have natural resistance to antibiotics survived and reproduced.
By what means do prokaryotes typically divide?
Binary fission
_______ is the self-replicating material present in nearly all living organisms; it is the main constituent of chromosomes and the carrier of genetic information.
DNA
How are DNA and RNA different?
DNA contains the bases A, G, C, and T; RNA contains the bases A, G, C, and U
Remains of a 365 million year old organism named Ichthyostega include features that suggest it spent time both in water and on land, indicating that it was a transitional species between fish and land-dwelling amphibians. The type of evidence is
Fossil record
In some populations, 1 in 500 people have sickle cell disease. What reason does the film give for why a potentially deadly, inherited disease is found at such high frequencies?
Individuals with one sickle cell allele are protected from malaria and do not have sickle cell disease, thus keeping the allele in the population.
Which of the following is used to construct a molecule of DNA?
Nucleotides
A particular antibiotic kills 99% of a bacterial population. What will be the result of the continued application of this antibiotic?
Over time, the antibiotic will become less effective at killing the bacteria.
________ is used in all steps of protein synthesis and carries the genetic information of many viruses.
RNA
If DNA directs the production of RNA, what does RNA make?
RNA makes proteins.
Which medication prevents viral infections by priming the immune system against a specific virus?
Vaccine
On what day does ovulation occur during the female reproductive cycle?
about day 14
nonbranching
ancestral population gradually changes into a new, distinct species
branching
ancestral population splits into two
When should a lactase supplement be taken in order to be most effective, and why?
at the same time the dairy product is consumed, so that the lactase will be in contact with the lactose
A ______ is a virus that specifically infects bacteria.
bacteriophage
The protein coat that surrounds the nucleic acid of a virus is called a
capsid
_______ are tightly coiled bundles of DNA and protein found in the nucleus of most living cells.
chromosomes
The skulls of humans and other primates have the same basic layout of bones, even though the heads are drastically different sizes and shapes. The type of evidence is
comparative anatomy
The _________ is a set of proteins that circulate in the blood, stimulating other defenses to help destroy an invader.
complement system
After DNA replication, __________.
each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand
novel features
for example, flowers, flight, or upright posture
The oldest known and most primitive bird is the 150-million-year old Archaeopteryx. Its remains display feathered wings, but its skeleton is otherwise similar to the two-legged dinosaurs that lived at that time. The type of evidence is
fossil record
Tristan da Cunha is a remote island in the Atlantic Ocean. In 1814, 15 people formed a colony there, one of whom carried a rare gene for blindness. The frequency of this gene is now 10 times higher on the island than on the mainland from which the settlers arrived. The mechanism of evolution is
founder effect
Which of the following results in the creation of gene families?
gene duplication
The evolution of populations due to chance is
genetic drift
The _______ is a collection of cells and organs that protect an organism's body from agents that can cause disease.
immune system
In which country would you most likely find a higher incidence of lactase persistence?
in a Scandinavian country where people historically raised dairy cattle and made cheese
A degenerative brain disorder transmitted by cannibalism is called
kuru
The ______ is the two-layered membrane that encases the nucleus of a eukaryotic cell, separating the nucleus from the cytoplasm.
nuclear envelope
A protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm is called a ______.
nuclear pore
The round body that sits inside the nucleus of a eukaryotic cell and makes ribosomal subunits from proteins and ribosomal RNA is known as the _______.
nucleolus
As climate change continues, species in which of the following marine ecosystems are likely to benefit the most?
rocky areas near shore
Researchers discovered that female gray tree frogs prefer to mate with males who sound the longest mating calls. The mechanism of evolution is
sexual selection
Antibodies are _____.
specialized proteins that attach to pathogens and disable them or mark them for destruction by immune cells
the formation of a new species
speciation
diversification
the emergence of subpopulations that have accumulated independent genetic changes
Where in the mother's body does a developing embryo implant?
the uterus
When a B cell binds to a virus or other pathogen, it _____.
becomes activated, divides rapidly, and thereby mounts a specialized response against the pathogen.
Fossils of some species of reptile are found only in West Africa and Brazil, even though these locations are currently separated by thousands of miles of Atlantic ocean. The type of evidence is
biogeography
Most of the animals found on the island of Madagascar are found nowhere else, indicating they evolved from ancestral populations after Madagascar was isolated from other continents. The type of evidence is
biogeography
Comparision of DNA sequences among single-celled organisms suggests that eukaryotes are more closely related to archaea than bacteria. The type of evidence is
bioinformatics
The amino acid sequence of human hemoglobin is more similar to the sequence of hemoglobin from dogs than it is to the sequence from fish. The type of evidence is
bioinformatics
A sudden volcanic eruption kills many members of a population of elk. By chance, the individuals that remain do not have the same mix of genes as the original population. The mechanism of evolution is
bottleneck effect
Although millions of prairie chickens once roamed the Midwest, their numbers dwindled to only 50 individuals in the 1990s. These few individuals have since produced a larger population. The genetic variation among the current population is quite low. The mechanism of evolution is
bottleneck effect