BIO184 LAB Practical 4 Study Guide Flashcards
(32 cards)
What is the Law of Segregation?
The principle stating that allele pairs separate during gamete formation, and randomly unite at fertilization.
What is the Law of Independent Assortment?
The principle stating that alleles for different traits are distributed to sex cells (& offspring) independently of one another.
What is ‘crossing over’?
The exchange of genetic material between homologous chromosomes during meiosis.
When does crossing over occur?
During prophase I of meiosis.
How is the distance between two genes on a chromosome related to crossing over?
Farther distance = more room for crossing over/recombination.
What happens if the recombination frequency between two genes reaches 50%?
These genes will effectively assort independently, similar to genes on different chromosomes.
Describe the Drosophila life cycle.
Eggs hatch to larvae, larvae pass through instar stages, form pupae, and adult flies emerge.
How is the allele for the white eye mutation in Drosophila written?
w
How is the wildtype allele for red eyes in Drosophila written?
w+
How can you distinguish male versus female Drosophila?
Males are typically smaller and have darker pigmentation on their abdomens, while females are larger with a more rounded abdomen.
What is a ‘pure breeding’ strain?
A strain that produces offspring identical to itself when self-fertilized.
What is an example genotype of a pure breeding strain?
AA or aa (homozygous dominant or recessive).
What is a ‘tester’ strain?
A strain used to determine the genotype of another strain by crossing.
What is an example genotype of a tester strain?
aa (homozygous recessive).
What are the genotypic and phenotypic ratios of the F1 progeny from a pure breeding wildtype x pure breeding homozygous recessive cross?
All F1 progeny will be heterozygous (Aa) and exhibit the wildtype phenotype.
What are the genotypic and phenotypic ratios of the F2 progeny when F1 progeny are crossed to a tester?
1:1 ratio of phenotypes and genotypes.
How do you calculate the probability of an event occurring?
By determining the total number of favorable outcomes divided by the total number of possible outcomes.
What is the Product Rule in probability?
The probability of A and B occurring in a defined order equals the product of their individual probabilities (prob of A x prob of B).
What is an example of the Product Rule?
The probability of getting tails twice when tossing a coin is (1/2)(1/2) = 1/4.
What is the Sum Rule in probability?
The probability of one or the other occurring equals the sum of their individual probabilities (prob of A + prob of B).
What is an example of the Sum Rule?
The probability of getting either heads or tails when tossing a coin once is (1/2) + (1/2) = 1.
What is the Binomial Expansion Equation used for?
To calculate the probability of an unordered sequence of events occurring.
What is the ‘general’ Null Hypothesis for any Chi-Squared test?
There is no statistically significant difference between the observed and expected outcomes.
What is a p-value in statistics?
The probability of obtaining results at least as extreme as the observed results, assuming the null hypothesis is true.
