Exam 15-22?
In a Hardy- Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele?
0.09
The figure above shows a simple metabolic pathway. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?
2
The following questions refer to this table of codons. A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe- leu- ile- val would be _____.
3' AAA- GAA- TAA- CAA 5'
A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is _____.
3' UCA 5'
Suppose 64% of a remote mountain village can taste phenylthiocarbamide (PTC) and must, therefore, have at least one copy of the dominant PTC taster allele. If this population conforms to Hardy- Weinberg expectations for this gene, what percentage of the population must be heterozygous for this trait?
48%
Use this model of a eukaryotic transcript to answer the following question(s). E = exon and I = intron 5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3' Which components of the previous molecule will also be found in mRNA in the cytosol?
5' UTR E1 E2 E3 E4 UTR 3'
If, on average, 46% of the loci in a species' gene pool are heterozygous, then the average homozygosity of the species should be _____.
54%
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?
A gene from an organism can theoretically be expressed by any other organism.
A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is _____.
AAA
The following questions refer to this table of codons. Refer to the figure above. What would the anticodon be for a tRNA that transports phenylalanine to a ribosome?
AAA
What does it mean when we say the genetic code is redundant?
More than one codon can specify the addition of the same amino acid.
In the process of transcription, _____.
RNA is synthesized
For a repressible operon to be transcribed, which of the following must occur?
RNA polymerase must bind to the promoter, and the repressor must be inactive.
In order for transcription to be initiated
RNA polymerase must have access to the DNA double helix and must also be capable of binding to the gene's promoter.
Which of the following statements best describes the termination of transcription in prokaryotes?
RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.
Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the _____.
binding of the anticodon to the codon and the attachment of amino acids to tRNAs
Alternative RNA splicing _____.
can allow the production of proteins of different sizes and functions from a single mRNA
Which of the following occurs in prokaryotes but not in eukaryotes?
concurrent transcription and translation
Through control of gene expression, a bacterial cell responds to changing ________ conditions.
enviromental
The maintenance of a constant environment in a cell is called ________.
homeostasis
A primary transcript in the nucleus of a eukaryotic cell is _____ the functional mRNA, while a primary transcript in a prokaryotic cell is _____ the functional mRNA.
larger than; the same size as
According to the central dogma, what molecule should go in the blank?DNA → _____ → Proteins
mRNA
Codons are part of the molecular structure of _____.
mRNA
The following questions refer to this table of codons. What amino acid sequence will be generated, based on the following mRNA codon sequence?5' AUG- UCU- UCG- UUA- UCC- UUG 3'
met- ser- ser- leu- ser- leu
Genetic variation _____.
must be present in a population before natural selection can act upon the population
For a biologist studying a small fish population in the lab, which Hardy- Weinberg condition is easiest to meet?
no gene flow
A site of negative genetic regulation where binding by repressor blocks transcription is the
operator.
A cluster of functionally-related genes that are regulated together and encoded into a single mRNA molecule is called a(n)
operon
A site at the 5' end of a gene where RNA polymerase attaches to initiate transcription is called a(n)
promoter.
Which of the following is a protein produced by a regulatory gene?
repressor
The reason for differences in the sets of proteins expressed in a nerve and a pancreatic cell of the same individual is that nerve and pancreatic cells contain different _____.
sets of regulatory proteins
Transcription in eukaryotes requires which of the following in addition to RNA polymerase?
several transcription factors
Transcription of structural genes in an inducible operon _____.
starts when the pathway's substrate is present
Which of the following is directly related to a single amino acid?
the three- base sequence of mRNA
In the structural organization of many eukaryotic genes, individual exons may be related to which of the following?
the various domains of the polypeptide product
