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Prokaryotic Gene Regulation
Eukaryotic Gene Regulation
Evolution
Population Genetcs
Stuff
100
What is the difference between an inducible and repressible operon?
inducible: normally off, catabolic pathway, exergonic repressible: normally on, anabolic pathway, endergonic
100
Which of the following is not a point at which gene regulation in eukaryotes can occur? A) degradation of mRNA B) RNA processing C) DNA replication D) gene transcription E) None of the above, they are all points at which a gene can be regulated.
C) DNA replication
100
In natural selection, _____ determines which phenotypes are successful. A) sample size B) chance C) birth rate D) the environment E) human intervention
D) the environment
100
The Afrikaner population in South Africa is derived from a few Dutch settlers. The frequency of Huntington’s disease in the current Afrikaner population is much higher then in Holland. This observation is an example of _____. A) mutation B) gene flow C) a bottleneck D) a founder effect E) natural selection
D) a founder effect
100
When analyzing the composition of Barr bodies (condensed X chromosomes), one would expect to observe _________ levels of __________. A) low …………………….. histone acetylation B) high ……………………. histone acetylation C) low …………………….. DNA methylation D) high ……………………. DNA methylation
D) high ……………………. DNA methylation
200
What sequence on DNA codes for the repressor protein?
Regulatory gene
200
Why do histones bind tightly to DNA? A. Histones are positively charged, and DNA is negatively charged. B. Histones are negatively charged, and DNA is positively charged. C. Both histones and DNA are strongly hydrophobic. D. Histones are covalently linked to the DNA. E. Histones are highly hydrophobic, and DNA is hydrophilic
A. Histones are positively charged, and DNA is negatively charged.
200
One of the constraints to natural selection is that it can only modify existing variations. This implies that _____. A) only individuals that can mutate to a given condition will survive B) available variations that favor a given environment may not be ideal C) new alleles are not generated on demand D) All of the above. E) Both B and C.
E) Both B and C.
200
If a population is not in Hardy-Weinberg equilibrium, which of the following would be true? A) The population is growing in numbers B) The allele frequencies in the population are remaining the same. C) The population is likely to go extinct. D) The gene pool has become fixed E) The population is evolving.
E) The population is evolving.
200
What is the most important factor to create the genetic differences that make adaptation by natural selection possible? A) gene duplication B) mutation to create new alleles C) sexual reproduction D) environmental factors E) All of the above are equally important.
C) sexual reproduction
300
In the trp operon, the repressor protein is synthesized in what form?
Inactive (unbound to the operator)
300
A proto-oncogene is _____________. A) a gene that when it undergoes cellular conversion promotes unregulated cell division B) often a gene that stimulates the cell cycle (such as ras) or inhibits the cell cycle (such as p53) C) can be converted to a oncogene by point mutations, translocations, or gene amplification D) often a gene important in gene regulation during embryonic development E) all of the above
E) all of the above
300
Which of the following statements regarding natural selection is false? A) Natural selection occurs through interactions with the environment. B) Natural selection acts on heritable traits in a population. C) Natural selection is the differential success in reproduction of individuals within a population. D) Natural selection may result in adaptation to environmental changes. E) None of the above, all the statements are true.
E) None of the above, all the statements are true.
300
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.7. What percentage of the population is expected to be homozygous for this allele? A. 3% B. 9% C. 30% D. 42% E. 49%
E. 49%
300
The Ras protein is involved in _____, and cancer-causing forms of the protein are usually _____. A. cell cycle regulation …………. hyperactive B. DNA replication …………. nonfunctional C. DNA repair …………. hyperactive D. cell-cell adhesion …………. nonfunctional E. cell division …………. nonfunctional
A. cell cycle regulation …………. hyperactive
400
Which molecule acts as the corepressor in the trp operon and the inducer in the lac operon?
corepressor: tryptophan inducer: allolactose/ lactose
400
Proteosomes recognize what on the protein that needs to be degraded?
Ubiquitin
400
"Improving the intelligence of an adult through education will result in that adult's descendants being born with a greater native intelligence." This statement reflects __________. A. natural selection as described by C. Darwin B. acquired characteristics as proposed by J. Lamarck C. uniformitarianism as described by C. Lyell D. scala naturae described by Aristotle E. catastrophism described by G. Cuvier
B. acquired characteristics as proposed by J. Lamarck
400
If allele frequencies in a population are changing due to chance or random events, what is happening? A) genetic drift B) adaptive radiation C) natural selection D) sympatric speciation E) allopatric speciation
A) genetic drift
400
The general process that leads to the differentiation of cells is called _________. A. determination B. specialization C. identification D. differentialization E. cellularization.
A. determination
500
Choose an operon we have covered in class (trp or lac) and describe what happens in the presence and absence of tryptophan (trp operon) or lactose (lac operon).
500
Describe the role of miRNA in eukaryotic gene regualtion.
500
Which of the following statements is not an inference of natural selection? A. Subsequent generations of a population should have greater proportions of individuals that possess favorable traits. B. An individual organism undergoes evolution over the course of its lifetime. C. Often only a fraction of offspring survive, because there is a struggle for limited resources. D. Individuals whose inherited characteristics best fit them to the environment should leave more offspring. E. Unequal reproductive success among its members leads a population to adapt over time.
B. An individual organism undergoes evolution over the course of its lifetime.
500
Consider a population with the following genotypic frequencies: 0.36RR + 0.48 Rr + 0.16 rr The allele frequency of the R allele is ________ and the allele frequency of the r allele is ______. A) 0.6 …………… 0.4 B) 0.08 …………… 0.92 C) 0.4 …………… 0.6 D) 0.06 …………… 0.04 E) insufficient information to determine
A) 0.6 …………… 0.4
500
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from the same embryonic tissues. How do biologists interpret these similarities? A. The bones are described as homologous structures. B. The bones can be explained by the principle of convergent evolution. C. Humans, bats, and dolphins share a common ancestor. D. both A and C E. all of the above
D. both A and C