midterm 2 Flashcards
t/f all genes have only 2 alleles.
false
t/f the expression of all genes is dependent only upon the inheritance of alleles from an individual’s parents and is independent of the environmental influences.
false
t/f an autosomal trait will occur with equal frequency in both males and females.
true
t/f in heterozygous individuals, only the recessive allele is expressed.
false
t/f crossing over can cause linked genes to not be linked.
true
t/f hemophilia is caused by a mutated allele that produces a defective form of the protein hemoglobin.
false
a trait that was expressed in the f1 generation in mendel’s experiment is considered ___
dominant
a cross between a red snapdragon flower and a while snapdragon flower produces a snapdragon with pink flowers. this flower color exhibits ___
incomplete dominance
if the inheritance of one trait is not related to the inheritance of another, it is because ___
they are not on the same chromosome
which of the following is not typically a step in analyzing a pedigree?
determining what mutated genes cause the trait.
finding that the inheritance of one trait had no effect on the inheritance of another became known as ___
law of independent assortment
while studying several generations of a particular family, a geneticist observed that a certain disease was found equally in males and females, and that all children that had the disease had at least one parent who also had the disease. the gene coding for this disease is probably ___
autosomal dominant
in humans, the risk of passing a genetic disorder onto one’s children can be assessed by
all the above
two phenotypically normal people that are heterozygous carriers of phenoketnuria ___
can produce children who will suffer the effects of the disease
an organism that has inherited two of the same alleles from the genes of its parents is called ___
homozygous
a diagram in while several generations of a family and the occurance of several genetic characteristics are shown is called ___
pedigree
the farther apart two genes are located on a chromosome, the ___
less likely they are inherited together
the law of independent assortment applies only to genes that are ___
located on different chromosomes
both sickle cell anemia and hemophilia ___
are caused by genes coding for defective proteins
in the f2 generation in Mendel’s experiments, the ration of dominant to recessive phenotype was ___
3:1
the ___ or physical appearance of an individual is determined by the alleles that code for the trait. while the set of alleles an individual has is called ___
phenotype
genotype
the likelihood that a specific event will occur is called ___
probability
uncorrected mistakes in genetic material often made when copying DNA are called ___
mutations
a trait that is determined by a gene found only on the x chromosome is called a ___ trait.
sex-linked
crossing two pea plants heterozygous for flower color should produce a phenotype ratio of ___ in the offspring.
3:1
the branch of biology that studies heredity is called ___
genetics
___ is a condition that impairs the blood’s ability to clot.
hemophilia
in 1994 the experiments of Oswald, Avery, and his associated demonstrated that DNA was responsible for
transforming r bacteria into deadly bacteria
Griffith’s experiment ___
caused non-harmful bacteria to become deadly
molecules of DNA are composed of long chains of __
nucleotides
in 1953, james watson and frances crick built a model of DNA with the configuration of ___
a double helix
during DNA replication, if a portion of the original strand is CCTAGCT, then the new strand will be
GGATCGA
cytosine makes up 38% of the nucleotides in the DNA of an organism, approximately what % of the nucleotides in the sample will be thymine?
12%
at the end of the replication process, each one of the two DNA molecules is composed of which of the following?
one new strand and one original strand
Avery demonstrated that treating heat killed s bacteria with DNA destroying enzymes ___
prevented harmless bacteria from transforming to deadly bacteria
a nucleotide consists of
a five carbon sugar, phosphate group, and a nitrogen base
biologists believe that by having genes of eukaryotic cells interrupted by non-coding sequences of nucleotides ___
provides evolutionary flexibility to (or through) genetic material
in bacteria, genes occur as ___
unbroken stretches of nucleotides
x-ray diffraction photographs by wil… and Franklin suggested that ___
DNA molecules arranged in tightly coiled helix
a scientist credited with establishing the structure of DNA are ___
watson and crick
a gene may be described as ___
a sequence of nucleotides that code for a sequence of amino acids
t/f it has been discovered that proteins are the genetic material rather than dna because proteins are more complex molecules
false
t/f introns can be shuffled between genes to create new genes over time
false
t/f after infecting e Coli bacteria with bacteria phages that have grown in media containing radioactive sulfur, then separating the virus from the bacteria, Hershey, and chase found that most of the radioactive substance was now in the bacteria, indicating that DNA was the genetic material
false
t/f multiple replication bubbles may open up in more than one portion of a eukaryotic DNA molecule at once, speeding up the rate of replication.
true
jumping genes that can move from one chromosomal location into another are called ___
transposons
a ___ is a preparation of killer micro organisms that are introduced into the body to produce immunity.
vaccine
in Griffith’s experiments, r bacteria will mix with heat-killed s bacteria and as a result, the r bacteria acquired a saccharide capsule. this changing nature of the organism is known as ___
transformation.
