Simple and Complex Traits Flashcards
External fertilization and transparent embryos make this organism an excellent model for studying early embryonic development.
Zebra fish
A researcher is interested in tracing the developmental fate of individual cells from the zygote to adulthood in real time. Which of the following model organisms would provide an opportunity to perform this analysis in real time?
C.elegans
The first eukaryotic genome to be analysed completely is of
Saccharomyces cerevisiae
The most important aspect in designing a genetic screen is
A clear and easy phenotype to score
Reverse genetic analysis is
deciphering genotype from phenotype
In a mutant screen, normally —– generation is screened for identifying the recessive phenotypes
F2 or M2
Complete dominance is an example of
A non-additive interaction between different alleles at the same locus
If an allele has the same phenotypic effect in heterozygotes as in homozygotes that is, the genotypes Aa and AA are phenotypically indistinguishable then the allele is
Dominant
The test to determine whether mutations are alleles of a particular gene based on the phenotypic effect of combining the mutations in the same individual is known as the
Complementation test
Summer squash color is determined by the interaction of more than one gene. The presence of CC or Cc allele combinations produces a squash that is white in color, and the C allele is epistatic to the G allele. The presence of GG or Gg produces a squash that is yellow in color, and ccgg produces a squash that is green. After two heterozygous squash are crossed one of the offspring is CcGg. What is the color of the offspring squash?
White
The work of Bateson and Punnett, who studied the combs of chickens, demonstrated that:
Two independently assorting genes can affect a trait
When two or more genes influence a trait, an allele of one of them may have an overriding effect on the phenotype. When an allele has such an overriding effect, it is said to be:
Epistatic
Bateson and Punnett mated purple sweet peas with white sweet peas. F1 hybrids were all purple in color. When the hybrids were mated a ratio of 9 purple : 7 white were observed in the F2 generation. Which of the following could best explain this observation?
Epistasis
cinnabar and scarlet mutants in Drosophila show a bright red eye phenotype. When crossed with each other, the scarlet mutant is able to complement the cinnabar mutant. This would indicate
Cinnabar and scarlet are mutations in two different genes
Mr Sweet analysed an F2 population segregating for two mutations that affect Drosophila wing shape. In the F2 population he obtained relatively fewer non-parental phenotypes. In order to be sure that this results did not happen by chance, Mr. Sweet would need to perform a
Chi-square test
“Early” mutants in peas flower 3 days earlier than the wild type peas. “Fast” mutants in peas flower 4 days earlier than wild type. When Benjamin performed double mutant analysis, he found the “early” “fast” double mutants were flowering 20 days earlier compared to wild type. The type of genetic interaction displayed in the double mutants is
Synergistic
According to the ABC model, An activity alone specifies sepals, A together with B specifies petals, B together with C specifies stamens and C alone specifies carpels. This leads to the arrangement of sepal, petal, stamen and carpel in wild type flowers. This model also suggests that A and C act against each other. What would you predict to be the arrangement of floral organs in a A/B double mutant?
(carpel)^4
The phenomenon in which genes on the same chromosome are separated from each other during meiosis and new combinations of genes are formed is known as
Recombination
Recombination is commonly the result of a process known as —- which occurs in prophase I of Meiosis
Crossing over
. P1 blue-flowered, short-stalked plants (FFSS) and white-flowered, long-stalked plant (ffss). The resulting F1 offspring (FfSs) were intercrossed to produce the following F2 progeny:
400 white long
