AP BIO: Chapter 14: Mendel and the Gene Idea Flashcards

Terms Definitions
characters
Mendel studies seven heritable features called what?
traits
Mendel's characters occured in alternatives called what?
true-breeding
Mendel used what type of varieties of pea plants, which emans that self-fertilizing parents always produce offspring w/ the parental form of the character?
true-breeding varieties
Mendel performed hybridizations in which he cross-pollinated contrasting what, and then allowed the next generation to self-polinate?
alleles
Alternate forms of genes, called what, account for variations in characters?
two alleles
An organism has what for each inherited trait, one recieved from each parent?
the dominant allele
What determines the organisms appearance, when two different alleles occur together?
the recessive allele
What has no observable effect on the organism's appearance, when two different alleles occur together?
separate
Allele pairs what during the formation of gamates, so an egg or sperm carries only one allele for each inherited character?
phenotype
What is an organism's expressed traits?
genotype
What is an organism's genetic make-up?
testcross
In a what, an organism expressing the dominant phenotype is crossed with a recessive homozygote to determine the genotype of this phenotypically dominant organism?
monohybrids
What are F1 offspring that are heterozygous for one character?
single character
In a monohybrid cross, the inheritance of a what is followed through the crossing of monohybrids?
F1
Mendel used dihybrid crosses between what kind of dihybrids to determine whether the two characters were transmitted independently of each other from the parent plants?
dihybrids
What are heterozygous for two characters?
four (AB, Ab, aB, ab)
If two pairs of alleles segregate independently, then gametes from an F1 hybrid generation (AaBb) should contain how many combination of alleles in equal quantities?
16 (4 x 4)
The random fertilization of these four classes of gametes should result in how many gamete combinations?
9:3:3:1
the random fertilization should produce four phenotype categories in what ratio? (how many offspring showing both dominant traits, how many showing one dominant trait and one recessive, how many showing the opposite dominant and recessive traits, and how many showing both recessive traits?)
the law of independent assortment
What principle states that pairs of alleles for each character segregate independently in the formation of gametes?
F2 progeny of dihybrid crosses
Mendel obtained these ratios when he categorized the what?
0 to 1
The probability scale goes from what to what?
1
The probabilities of all possible outcomes must add up to what?
the rule of multiplication
What states that the probability of a particular genotype being formed by fertilization is what to the product of the probabilities of forming each type of gamete need to produce the genotype?
the rule of additon
If a genotype can be formed in more than one way, then what rule states that its probability is equal to the sum of the separate probabilities of the different, mutually exclusive ways the event can occur?
separate monohybrid cross
The probability of a particular genotype arising from a cross can be determined by considering each gene involved as a what and then multiplying the probabilities of all the independent events involved in the final genotype?
larger the sample size
The what, the more closely the results will conform to statistical predictions?
inheritance patterns
what are more complex than predicted by simple Mendelian genetics?
spectrum of dominance
Alleles may show varying degrees of dominance and recessiveness along a what?
complete dominance
In the case of an allele showing what, the phenotype of the heterozygote is indistinguishable from that of the dominant homozygote?
codominance
At the other end of the continuum, alleles that exhibit what will both affect the phenotype in separate, distinguishable ways, as in the case of the MN blood group?
incomplete dominance
Intermediate phenotypes are characteristic of alleles showing what?
a phenotype intermediate
The F1 hybrids have a what between that of the parents?
1:2:1
The F2 show a what phenotypic and genotypic ratio?
the molecular level
Even when alleles exhibit dominance or incomplete dominance at the pheontypic level, both alleles may be expressed at what level?
Tay-Sachs
What disease is a lethal disorder in which brain cellslacck a critical enzyme and are unable to metabolize a type of lipid that then accumulates and damages the brain?
recessive; intermediate between both homozygotes; codominant
In a heterozygote, the Tay-Sachs allele is what at the organismal level; at the biochemical level, the enzyme activity level is what; and at the molecular level, the alleles are what in that eac produces its enzyme product, either normal or dysfunctional?
two
Most genes exist in more than how many allelic forms?
pleitropy
What is the characteristic of a single gene having multiple phenotypic effects in an individual?
epistasis
In what, a gene at one locus may affect the expression of another gene?
epistasis
F2 ratios that differ from the typical 9:3:3:1 often indicate what?
Quantitatve characters
What as height or skin color, vary along a continuum in a population?
polygenic inheritance
Such phenotypic graduations are usually due to what?
polygenic inheritance
In what does two or more genes have an addictive effect on one character?
one
Each dominant allele contributes how many units to the phenotype?
norm of reaction
Genotypes have a phenotypic range called a what within which the environment influence phenotypic expression?
multifactoral
Polygenic characters are often what?
multifactoral
What means that a combination of genetic and environmental factors influences phenotype?
family pedigree
What is a family tree within the history of a particular trait shown across the generation?
circle; square; solid symbols
In a pedigree, what represent females, what for males, and what symbols indicate individuals that express the trait question?
cystic fibrosis
What is the most common lethal genetic disease in the United States; it is found more frequently in people of European descent?
cystic fibrosis
What recessive allele results in defective chloride channels in certain cell membranes?
double lines
Consanguineous matings, between siblings or close relatives, are indicated on pedigrees by what?
Huntington's disease
What is a degenerative disease of the nervous system that doesn't develop until later in life?
Amniocentesis
What is a procedure that extracts a small amount of amniotic fluid from the sac surrounding the fetus?
Chlorionic villus sampling
What is a technique in which a small amound of fetal tissue is suctioned from the placenta?
codominance
What is a phenotype in which both dominant alleles are expressed in the heterozygote?
amniocentesis
What is a technique for determining genetic abnormalities in a fetus by the presence of certain chemicals or defective fetal cells in the amniotic fluid, obtained by aspiration from a needle inserted into the uterus?
dihybrid cross
What's a breeding experiment in which offspring of a cross of parental varieties differing in two traits are mated?
epistasis
What's a phenomenon in which one gene alters the expression of another gene that's independently inherited?
genotype
What's the genetic makeup of an organism?
monohybrid cross
What'sa breeding experiment that crosses offspring of a cross of parental varieties differing in a single character?
phenotype
What's the physical and physiological traits of an organism?
pleiotropy
When does a single gene impact more than one characteristic?
polygenic
What's an addictive effect of two or more gene loci on a single phenotypic character?
/ 65
Term:
Definition:
Definition:

Leave a Comment ({[ getComments().length ]})

Comments ({[ getComments().length ]})

{[comment.username]}

{[ comment.comment ]}

View All {[ getComments().length ]} Comments
Ask a homework question - tutors are online