Bio Exam 4 – Flashcards
Unlock all answers in this set
Unlock answersquestion
_____ bind(s) to DNA enhancer regions.
answer
Activators
question
Which of the following events in transcription occurs last?
answer
The mRNA is released from RNA polymerase.
question
What is the function of the promoter site in transcription?
answer
It is the site at which RNA polymerase binds to start transcription.
question
Which nucleic acid is translated to make a protein?
answer
mRNA
question
At which site do new tRNAs enter the ribosome?
answer
First binding site in the ribosome (A site)
question
True or false. A tRNA with an anticodon complementary to the stop codon catalyzes the reaction by which translation is terminated.
answer
False
question
Which term describes a circular piece of bacterial DNA that is used in cloning?
answer
Plasmid
question
Which of the following steps must be performed first when using recombinant DNA technology to produce a human protein in bacterial cells?
answer
The human gene is isolated from a human cell nucleus.
question
True or false. The term "sticky ends" refers to the ends on DNA that are generated by restriction enzymes, which can base pair with any DNA molecules that contain complementary sticky ends.
answer
True
question
Which of the following is LEAST likely to be a health problem for someone with cystic fibrosis?
answer
obesity
question
The allele that causes cystic fibrosis is recessive. An individual who is heterozygous for cystic fibrosis
answer
is a carrier.
question
If Sophie has a brother or sister from the same parents, what are the chances that sibling would have cystic fibrosis?
answer
25%
question
If someone is a carrier of a recessive genetic disorder, it means he or she has __________ of the allele, and __________ exhibit symptoms of the disorder.
answer
one copy; does not
question
Which of the following do you think contributed the most to the success of Rhys' gene therapy?
answer
Doctors were replacing only one gene, and they only had to insert that gene into bone marrow cells.
question
Theoretically, which of the following diseases should be the easiest to treat through gene therapy, considering the targeted organs and tissues where the corrected gene must be delivered?
answer
diabetes, since the target cells are found only in the pancreas
question
A codon of mRNA should be UUC, but a mutation changed the first nucleotide base of the original DNA template to a thymine (T). Which anticodon would bind to the mutated version of the codon?
answer
UAG
question
What is a plasmid?
answer
circular extra-chromosomal DNA found in bacteria
question
What process replaces defective human genes with normal, functional genes?
answer
gene therapy
question
Which disease would be the most likely candidate for gene therapy?
answer
Hemophilia
question
Why was golden rice engineered?
answer
To produce beta-carotene
question
What happens right after a recombinant plasmid is made during the cloning process?
answer
The recombinant plasmid is reinserted into a bacterial cell.
question
In some cells, which process may be affected by repressors that regulate the amount of gene product present?
answer
RNA transcription.
question
Which types of organisms would be most useful as model organisms with which to compare human DNA?
answer
organisms from all kingdoms of life
question
What ability of individual stem cells is described by the term totipotent?.
answer
To become any other somatic cell type
question
Which of the following is the immediate ancestor of modern humans?
answer
Homo erectus
question
Which of the following has been given the nickname "hobbit?"
answer
Homo floresiensis
question
Which of the following is the first and least known of the Homo species?
answer
Homo habilis
question
The famous skeleton "Lucy" was found where?
answer
Ethiopia
question
Which of the following refers to the change in the characteristics in a population over time?
answer
the process of evolution
question
What is the difference between a scientific theory and a popular theory?
answer
A scientific theory can explain all known evidence, whereas you can probably find evidence to dispute a popular theory.
question
How is a biological population different from the population of a whole ecosystem, such as a rainforest?
answer
A biological population consists of all one species instead of many species.
question
When Darwin referred to the Linnaean classification system, what did he suggest?
answer
All members of the same family have more in common than all members of the same order.
question
Which members of the primate order have more ape-like characteristics?
answer
ancient hominins
question
Which alternative to the theory of evolution proposes that today's living things evolved from multiple common ancestors?
answer
the hypothesis of separate types
question
Which of the following anatomical features of the 3.2-million-year-old Australopithecus fossil known as "Lucy" suggest she was a bipedal hominid?
answer
a much shorter hip bone that is broader from front to back and wraps around the side
question
How do scientists know that the hominid called "Ardi" is about 4.4 million years old?
answer
by using radiometric dating techniques on the volcanic deposits found above and below the layer containing Ardi
question
Which organisms are most closely related?
answer
Cougar and lynx, which are both in the family Felidae
question
How are a bat's wing, a sea lion's flipper, and a lion's front leg related?
answer
They are all homologous structures.
question
What is biological evolution?
answer
the gene changes occurring in populations over many generations
question
What is the process by which populations adapt to a changing environment
answer
natural selection
question
Which explanation could be considered a Lamarckian argument?
answer
As giraffes stretched their necks to eat leaves, they passed this trait to their offspring and subsequent generations of giraffes developed long necks.
question
What is meant by consilience, which supports the theory of common descent?
answer
Observations from many different sources support the theory.
question
How do scientists determine the dates of fossils?
answer
measure the ratio of a radioactive element to the decay products
question
Which human structure has a modification that allows for an upright stance?
answer
pelvis
question
The Carolina chickadee, boreal chickadee, and black-capped chickadee are small songbirds that look and sound very similar to one another. What could account for their differences?
answer
Geographical separation
question
Which hypothesis suggested that species arise separately and then adapt to a changing environment over time?
answer
transformation hypothesis
question
In a species of snail, dark-shelled individuals are better hidden from bird predators in the shady forest, while light-shelled individuals are better hidden in well-lit brushy edge areas. If there were no areas of intermediate brightness in this habitat,which type of selection would act on shell color in these snails?
answer
Disruptive selection
question
Small lizards have difficulty defending their territory, but large lizards are more likely to be preyed upon by owls. Which type of selection would act on body size in these lizards under these conditions?
answer
Stabilizing selection
question
Has evolution by natural selection recently occurred in the worldwide populations of Mycobacterium tuberculosis?
answer
Yes, the frequency of the adaptive allele for drug resistance has increased over time.
question
What is unique about deer mice?
answer
They are the most populous mouse found in North America.
question
You wish to research how genetics determine color of deer mice. How many genes should you focus on?
answer
1
question
The three-spine stickleback typically lacks armor in fresh water. Why?
answer
To allow for faster growth.
question
In natural selection, what changes in a population over time?
answer
the frequency of an allele for a particular gene in a population
question
What do alleles give rise to in a population?
answer
variation
question
Which of the following is the best definition of adaptation?
answer
a trait favored by natural selection
question
Why have public health officials once again become very concerned about tuberculosis in the 21st century?
answer
Antibiotic-resistant strains of tuberculosis are on the rise.
question
How is artificial selection different from natural selection?
answer
Artificial selection is selection by human choice rather than environmental change.
question
How would evolutionary biologists define the fitness of an organism?
answer
the ability of an individual to survive and reproduce
question
What is the source of variation in a population?
answer
spontaneous mutations
question
If a population of fruit flies is exposed to a food source with high alcohol content, what would happen to the population?
answer
Individuals who are not tolerant of the ethanol would die, and individuals who are naturally tolerant would survive.
question
What is the most important factor in determining the way that a population evolves?
answer
the environment
question
When Darwin was developing his ideas about natural selection, in what area did he have a limited understanding?
answer
Darwin lacked an understanding about how variation was passed on to offspring
question
How do bacterial mutations make bacteria resistant to antibiotics?
answer
The mutation either disables or counteracts the antibiotic so the bacteria can live in the presence of antibiotics.
question
What is the strategy behind combination drug therapy?
answer
A greater number of changes are required in genetic material for resistance to develop if a greater number of drugs are used.
