Delgado Bio 141 Test 4
steps in excision repair
1-recognition of damage 2-removal of the damaged region 3-resynthesis using the information on the undamaged strand as a template
how many hydrogen bonds form between cytosine and guanine in the DNA double helix
3
4 nitrogen bases in DNA
Adenine, Thymine, Guanine, Cytosine
the form that was not expressed in the F1 plants as
Recessive
Each DNA molecule is composed of two strands that run antiparallel and composed of 2 phosphodiester strands whose model is this a part of
Watson-Crick model
Franklin used x-ray ____ to suggest that DNA has a helical structure
diffraction
On this strand, the removal of the last primer leaves a gap that cannot be primed at the ends of the chromosome - this is known as
lagging
as the lagging strand is being synthesized, adjacent Okazaki fragments are joined by the enzyme DNA
ligase
DNA replication in eukaryotic cells is complicated by the fact that eukaryotic cells have
linear chromosomes
the level of telomerase stays high in ________, despite their age
lymphocytes
used for independent events
multiplication rule
Agents that cause mutation are known as
mutagens
Meselson and Stahl used two isotopes of _____ in their DNA replication experiments so that the daughter strands could be distinguished from the parental strands
nitrogen
1' 3' 5'
nitrogen base OH group phosphate group
In bacterium, termination of replication occurs
opposite to the origin (the termination site)
A consistent graphical representation of mating's and offspring over multiple generations for a particular trait
pedigree
components of a nucleotide
phosphate group, 5 carbon sugar, nitrogenous base
Adjacent nucleotides in the same DNA strand are held together by covalent bonds known as
phosphodiester bonds
Continuous phenotypic variation results from
polygenic inheritance and independent segregation of genes
attaches a nucleotide to the 3' end of the DNA strand
polymerase
three items required for DNA replication
polymerase nucleotides template
Makes a 10-12 base-pairs complementary primer to the DNA
primase
All DNA polymerases require a short strand of DNA or RNA , is called a _____, to begin their synthesis
primer
in the replisome, the ______ is composed of primase, helicase, and accessory proteins that prime the lagging strand
primosome
the function of telomeres is to
protect the ends of chromosomes
pollen from a white-flowered plant is used to fertilize a purple-flowered plant, while pollen from a purple-flowered plant is used to fertilize a white-flowered plant
reciprocal fertilization
the DNA controlled by an origin is called a
replicon
The principal of ______ is that 2 alleles for a genes separate during gamete formation and are rejoined at random, one for each parent, during fertilization.
segregation
takes place within an individual flower if it is not disturbed
self-fertilization
DNA replication that leads to the production of double helices with one parental strand and one newly synthesized strand is consistent with
semiconservative replication
Two general categories to DNA repair are
specific and nonspecific
three differences in prokaryotic an eukaryotic replication
structure of chromosomes (linear vs circular) number of origins of replication complexity of enzymology
steps of lagging strand synthesis
synthesize primers using primase synthesize DNA replace RNA primers with DNA seal nicks in the DNA
leading strand
synthesized continuously
lagging strand
synthesized in small fragments that are later connected
An enzyme that prevents chromosomal shortening by attaching a repeat sequence to the ends of chromosomes is
telomerase
short, repeated sequences of DNA are a characteristic of
telomeres
the cross of an individual who has a dominant phenotype with an individual who is homozygous recessive for that gene is known as
testcross
Griffith's experiments were important because they showed
that the genetic material could be passed from one cell to another
why do eukaryotic cells have multiple origins of replication
to ensure timely replication of multiple, relatively large chromosomes
In the Meselson-Stahl experiment, what was the expected composition of DNA molecules after one round of replication, if the conservative model was correct?
two densities should be observed: the DNA strands would be either all heavy or all light
The DNA structure proposed by Watson and Crick involves
two grooves (major and minor)- double stranded structure a helical structure a sugar phosphate backbone
used for mutually exclusive events
addition rule
In a DNA double helix, two hydrogen bonds form between
adenine and thymine
The Law of Independent assortment states that in a dihybrid cross, the _____ of each gene assort independently.
alleles
DNA'S phosphodiester _____ is composed of sugars and phosphates
backbone
the expression of two different alleles simultaneously in the heterozygote is called
codominance
pollen collected from a white flower placed introduced into a purple flower with male parts removed
cross-fertilization
In the Meselson-Stahl experiment, what was the expected composition of DNA molecules after two rounds of replication, if the semiconservative model was correct-
half of the molecules would have two light strands and half would have a heavy and light strand
the enzyme ______ uses ATP to unwind the DNA template
helicase
these individual bonds are low-energy, but together they are strong enough to hold the two strands of a double-stranded DNA molecule together
hydrogen bonds between basepairs
Mendel"s three stages of his experiments
1. allowing plants to self-cross to ensure they are true-breeding 2. reciprocal crosses between true-breeding varieties 3. allowing hybrid offspring to self-fertilize
does DNA or RNA polymerases require primers to begin synthesis
DNA
unwinds the double helix
DNA helicase
The purpose of the Hershey Chase experiments was to determine whether a bacteriophage injected ____ or ______ into bacteria
DNA or Protein
which enzyme covalently links nucleotides together
DNA polymerase
The form of each trait that is expressed in the F1 generation.
Dominant
when the interaction of genes alters genetic ratios, this is called
Epistasis
the experiments with radioactively labeled phage that showed that DNA was the genetic material were performed by
Hershey and Chase
Alleles involved in human blood types that are co dominant are
IA and IB (little and b)
the phenotype of the heterozygote is intermediate between the two homozygotes
Incomplete Dominance
the experiments used to distinguish between the three potential DNA replication mechanisms were performed by
Meselson and Stahl
telomerase uses ________ as a template
a short internal RNA
Two main eukaryotic DNA polymerases that extend DNA are
epsilon and delta
based on replication proteins, DNA replication in archaea is most similar to that of
eukaryotes
by convention, the sequence of DNA bases is usually written in the ____' to ____' direction.
five to three
Relieves coiling in DNA strands ahead of the replication fork
gyrase
The enzyme DNA ____ is the topoisomerase involved in DNA replication
gyrase
A Punnett square has rows and columns which represent gametes made by males and females. At the intersection of each row and column e combine the corresponding gametes to produce the genotype of a potential _______
zygote