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