bio 103 ch 12-15 questions
In a cross of Aa Bb cc X Aa Bb Cc, what is the probability of obtaining an indivudual with the genotype of AA Bb Cc
1/16
What is the probability of obtaining an individual with the genotype bb from a cross between two individuals with the genotype Bb
1/4
Japanese four o'clocks that are red and tall are crossed to white short ones, producing an F1 that is pink and tall. If these genes assort independently, and the F1 is self-crossed, what would you predict for the ratio of F2 phenotypes
3 red tall: 6 pink tall: 3 white tall: 1 red short: 2 pink short: 1 white short
How many map units separate two alleles if the recombination frequency is .07?
7cM
chargaff studied the composition of dna from different sources and found that
A=T and G=C
What cellular process is responsible for genetic recombination?
Crossing between homologues.
Which of the following is NOT a part of Mendel's five-element model?
If an allele is present it will be expressed.
Which of the following genotypes due to nondisjunction of sex chromosomes is lethal?
OY
The F1 generation of the monohybrid cross purple (PP) x white (pp) flower pea plants should
all have purple flowers
An organisms ______ is defined by its ______
alleles, prototype
the meselson and stahl experiment used a density label to be able to
distinguish between newly and old replicated strands
basic mechanism of dna replication is semiconservative with two new molecules
each with one new and one old strand
eukaryotic transcription differs from prokaryotic in that
eukaryotes have 3 RNA polymerases
the experiements with nutritional mutants in neurospora by beadle and tatum provided evidence that
genes specify enzymes
What was the key finding from griffiths experiments using live and heat-killed pathogenic bacteria
genetic material can be transferred from dead to live bacteria.
A recessive sex-linked gene in humans leads to a loss of sweat glands. A woman heterozygous for this will
have patch of skin with and wihtout sweat glands
When you cross true-breeding tall and short tobacco plants you get an F1 that is intermediate in height. when this F1 is self-crossed it yields an F2 with a continuous distribution of heights. Whats the best explanation?
height is determined by the additive effects of many genes
succesful DNA synthesis requires
helicase, dna primase, dna ligase
what is the central dogma of molcecular biology
information passes from DNA to RNA to protein
What property distinguished mendels investigation from previous studies
mendel quantified his results
What is the relationship between mutations and evolution
mutations create new alleles
an inversion will
only cause a mutant phenotype if the inversion breakpoints fall with gene
In comparing gene expression in prokaryotes and eukaryotes
prokaryotic genes produce more than 1 protein. both produce mRNAS
RNA polymerase binds to a _____ to initiate _____
promoters, transcription
The map distance between two genes is determined by the
recombination frequency
the synthesis of telomeres
requires telmerase, which uses an internal RNA as a template
How does maternal inheritance of mitochondrial genes differ from sex linkage?
since mitochondria are inherited from the mother, females and males are equally affected.
in DNA ligase was removed from replication this would have a greater affect on
synthesis on the lagging strand vs the leading strand
one common featurue of all dna polymerases is that they
synthesize dna in the 5'-to-3' direction
An anticodon would be found on which of the follows types of RNA?
tRNA
Phenotypes like height in humans, which show a continuous distribution, are usually the result of?
the action of multiple genes on a single phenotype
During translation, the codon in mRNA is actually "read" by
the anticodon in tRNA
the enzyme that forms peptide bonds is called peptidyl transferase because it transfers
the growing peptide from a tRNA to the next amino acid
which of the following is not a component of dna?
the pyrimidine uracil
which of the following is not part of the watson-crick model of structure of dna
the two dna strands are oritented in parralell 5-3
Why is the white-eye phenotype always observed in males carrying the white-eye allele?
Because the allele is located on the X chromosome, males only have 1 X
codon CCA could be mutated to produce
a silent mutation
Mendels model assumes that each trait is determined by a single factor with alternate forms. we know this is too simplistic and that
a single gene can affect more than one trait, and traits may be affected by more than one gene
In an organism's genome, autosomes are
all of the chromosomes other than sex chromosomes
the difference in leading- versus legging- strand synthesis is a consquence of
both the phsycial structure of DNA and the action of polymerase enzyme
the splicing process
can produce multiple mRNA's from the same transcript
Down syndrome is the result of trisomy for chromosome 21. whi is this trisomy viable and trisomy for most other chromosomes not?
chromosome 21 is a small chromosome with few genes so this does less to disrupt the genome.
in the gneetic code, one codon
consists 3 bases, and specifies a single amino acid
hershey and chase used radioactive phspourus and sulfur to
differentially label DNA and protein
As real genetic distance increases, the distance calculated by recombination frequency becomes an
underestimate due to multiple crossovers that cannot be scored.
genes that are on the same chromosome can show independent assortment
when they are far enough apart that odd numbers of crossovers is equal to even.