BIO 3001: EXAM 1 QUESTIONS &
ANSWERS 100% CORRECT!!
Mendel's Experiments & Mendelian Crosses - ANSWER1990, monohybrid, dihybrid,
trihybrid
gene, allele, dominant, recessive - ANSWERgene: coded information in the form of
hereditary units
allele: alternative versions of genes
dominant: determined the organism's appearance
recessive: has no noticeable effect on the organism's appearance
homozygous, heterozygous, genotype, phenotype, pleiotropy, epistasis -
ANSWERhomozygous: an organism that has a pair of identical alleles for a
character (PP, pp)
heterozygous: an organism that has two different alleles for a gene
phenotype: an organism's appearance or observable traits
genotype: genetic makeup, pair of alleles
pleiotropy: multiple phenotypic effects from one gene
epistasis: the phenotypic expression of a gene at one locus alters that of a gene at a
second locus
thomas hunt morgan experiments with white-eyed male fly: genes are part of
chromosomes - ANSWERwild type: the phenotype for a character most commonly
observed in natural populations such as red eyes for Drosophila melanogaster.
mutant phenotypes: traits that are alternative to the wild type, such as white eyes in
Drosophila.
Morgan's finding of the correlation between a particular trait and an individual's sex
provided support for the chromosome theory of inheritance - namely, that a specific
gene is carried on a specific chromosome.
In addition, Morgan's work indicated that genes located on a sex chromosome
exhibit unique inheritance patterns.
why are Drosophilia melanogaster excellent animals for genetic research? -
ANSWERprolific breeders, small, easily maintained, fruit flies only have 4 pairs of
chromosomes which are easily distinguishable with a light chromosome
mendel's 2 laws - segregation and independent assortment - ANSWERsegregation:
the two alleles for a heritable character segregate during gamete formation and end
up in different gametes
independent assortment: each pair of alleles segregates independently of each other
pair of alleles during gamete formation
how mendel's 2 laws relate to the phases of meiosis - ANSWERsegregation:
the R & r alleles segregate in anaphase I, yielding two types of daughter cells for this
locus.
, each gamete gets one long chromosome with either the R or r allele at metaphase II.
recombination recombines the R & r alleles at random.
independent assortment:
alleles at both loci segregate at anaphase I, yielding four types of daughter cells,
depending on the chromosome arrangement at metaphase I.
each gamete gets a long and a short chromosome in 1 of 4 allele combinations.
fertilization results in the 9:3:3:1 ratio in the f2 generation.
phases of meiosis - ANSWER1. prophase - homologous chromosomes find each
other & crossing over between chromatids occurs
2. metaphase - homologous chromosomes are paired up on the equatorial plate
3. anaphase - creation of haploid gametes
4. telophase - nuclei reform - 2 haploid cells
gamete formation - ANSWERyou produce gametes by a variation of cell division
called meiosis, which yields nonidentical daughter cells that have only one set of
chromosomes, half as many chromosomes as the parent cell
- meiosis in the human cells occurs only in the gonads (ovaries and testes)
branching diagram for two gene crosses (dihybrid) - ANSWER
branching diagram for a trihybrid cross - ANSWER
chromosomes and inheritance - ANSWER
discovery of mendel, 1900 - ANSWERpublished in 1866, discovered in 1900
A.H. Strutevant, linked genes and gene mapping using cross-over (recombination)
frequencies - ANSWERGenetic Map: an ordered list of the genetic loci along a
particular chromosome.
Recombination Frequency: the percentage of recombinant offspring depends on the
distance between genes on a chromosome.
The further apart two genes are, the higher the probability that a crossover will occur
between them and therefore the higher the recombination frequency - the greater the
distance between two genes, the more points there are between them where
crossing over can occur.
Linkage Map: a genetic map based on recombination frequencies.
Map Units: Sturtevant expressed he distances between genes in map units, defining
one map unit as equivalent to a 1% recombination frequency.
map problem - ANSWER
molecular basis of inheritance - ANSWER
griffith expriment - ANSWEREvidence that DNA can transform bacteria
While attempting to develop a vaccine against pneumoniae, British medical officer
named Frederick Griffith was studying streptococcus pneumoniae, a bacterium that
causes pneumonia in animals. - Griffith had two strains (varieties) of the bacterium,
one pathogenic (disease causing) and one nonpathogenic (harmless).
ANSWERS 100% CORRECT!!
Mendel's Experiments & Mendelian Crosses - ANSWER1990, monohybrid, dihybrid,
trihybrid
gene, allele, dominant, recessive - ANSWERgene: coded information in the form of
hereditary units
allele: alternative versions of genes
dominant: determined the organism's appearance
recessive: has no noticeable effect on the organism's appearance
homozygous, heterozygous, genotype, phenotype, pleiotropy, epistasis -
ANSWERhomozygous: an organism that has a pair of identical alleles for a
character (PP, pp)
heterozygous: an organism that has two different alleles for a gene
phenotype: an organism's appearance or observable traits
genotype: genetic makeup, pair of alleles
pleiotropy: multiple phenotypic effects from one gene
epistasis: the phenotypic expression of a gene at one locus alters that of a gene at a
second locus
thomas hunt morgan experiments with white-eyed male fly: genes are part of
chromosomes - ANSWERwild type: the phenotype for a character most commonly
observed in natural populations such as red eyes for Drosophila melanogaster.
mutant phenotypes: traits that are alternative to the wild type, such as white eyes in
Drosophila.
Morgan's finding of the correlation between a particular trait and an individual's sex
provided support for the chromosome theory of inheritance - namely, that a specific
gene is carried on a specific chromosome.
In addition, Morgan's work indicated that genes located on a sex chromosome
exhibit unique inheritance patterns.
why are Drosophilia melanogaster excellent animals for genetic research? -
ANSWERprolific breeders, small, easily maintained, fruit flies only have 4 pairs of
chromosomes which are easily distinguishable with a light chromosome
mendel's 2 laws - segregation and independent assortment - ANSWERsegregation:
the two alleles for a heritable character segregate during gamete formation and end
up in different gametes
independent assortment: each pair of alleles segregates independently of each other
pair of alleles during gamete formation
how mendel's 2 laws relate to the phases of meiosis - ANSWERsegregation:
the R & r alleles segregate in anaphase I, yielding two types of daughter cells for this
locus.
, each gamete gets one long chromosome with either the R or r allele at metaphase II.
recombination recombines the R & r alleles at random.
independent assortment:
alleles at both loci segregate at anaphase I, yielding four types of daughter cells,
depending on the chromosome arrangement at metaphase I.
each gamete gets a long and a short chromosome in 1 of 4 allele combinations.
fertilization results in the 9:3:3:1 ratio in the f2 generation.
phases of meiosis - ANSWER1. prophase - homologous chromosomes find each
other & crossing over between chromatids occurs
2. metaphase - homologous chromosomes are paired up on the equatorial plate
3. anaphase - creation of haploid gametes
4. telophase - nuclei reform - 2 haploid cells
gamete formation - ANSWERyou produce gametes by a variation of cell division
called meiosis, which yields nonidentical daughter cells that have only one set of
chromosomes, half as many chromosomes as the parent cell
- meiosis in the human cells occurs only in the gonads (ovaries and testes)
branching diagram for two gene crosses (dihybrid) - ANSWER
branching diagram for a trihybrid cross - ANSWER
chromosomes and inheritance - ANSWER
discovery of mendel, 1900 - ANSWERpublished in 1866, discovered in 1900
A.H. Strutevant, linked genes and gene mapping using cross-over (recombination)
frequencies - ANSWERGenetic Map: an ordered list of the genetic loci along a
particular chromosome.
Recombination Frequency: the percentage of recombinant offspring depends on the
distance between genes on a chromosome.
The further apart two genes are, the higher the probability that a crossover will occur
between them and therefore the higher the recombination frequency - the greater the
distance between two genes, the more points there are between them where
crossing over can occur.
Linkage Map: a genetic map based on recombination frequencies.
Map Units: Sturtevant expressed he distances between genes in map units, defining
one map unit as equivalent to a 1% recombination frequency.
map problem - ANSWER
molecular basis of inheritance - ANSWER
griffith expriment - ANSWEREvidence that DNA can transform bacteria
While attempting to develop a vaccine against pneumoniae, British medical officer
named Frederick Griffith was studying streptococcus pneumoniae, a bacterium that
causes pneumonia in animals. - Griffith had two strains (varieties) of the bacterium,
one pathogenic (disease causing) and one nonpathogenic (harmless).
