Mendelian Genetics Review

Flashcards for reviewing Mendelian Genetics lecture notes.

What were the five keys to Gregor Mendel's success in his discoveries?

Controlled crosses, use of pure-breeding strains, use of dichotomous traits, quantification of results, use of replicate, reciprocal, and test crosses.

What did Mendel learn from his carefully planned and executed experiments and precise analysis?

He disproved the blending theory of heredity and produced a new theory.

According to Mendel, what happens when two different alleles are present in an organism?

One of the alleles is able to block the other (is dominant vs. is recessive).

What conclusion did Mendel make regarding how factors are inherited to achieve the observed ratios of traits?

Factors are likely inherited in pairs and those pairs are randomly rearranged each generation.

What do we now refer to Mendel's 'factors' as?

Genes or Loci

What are the steps to using a Punnett square?

determine the genotypes of the parent organisms, write down your cross (mating), draw a punnett square, split the letters of the genotype for each parent & put them outside the p-square, determine the possible genotypes of the offspring by filling in the p-square, summarize results (genotypes & phenotypes of offspring)

What were the major conclusions of Mendel's work?

Characteristics were governed by distinct units of inheritance (genes); Each organism has/inherits two copies each gene, one from each parent; The two genes may be identicalto one another or non-identical (alleles); Gametes (reproductive cells) must therefore carry only one copy of the gene for each trait; Principle of Independent Segregation and Assortment

When looking at 2+ traits simultaneously, what did Mendel discover?

The alleles for each trait segregate independently AND do not influence the inheritance (independent assortment) of the second trait

What is the forked-line diagram used for?

Used to determine gamete genotypes and frequencies.

How do Mendelian inheritance patterns relate to probability?

The ratios are what is predicted, not what is guaranteed.

In probability theory, what does the Product Rule (or multiplication rule) relate to?

Independent of one another events

In probability theory, what does the Sum Rule (or addition rule) relate to?

Joint probability or mutually exclusive events

In probability theory, what does Conditional Probability relate to?

Asked after the cross; modifies the condition.

In probability theory, what does the Binomial Probability relate to?

Predicting one event from many outcomes

What is conditional probability?

The probability of an event (A), given that another (B) has already occurred.

What is the likelihood that a yellow-seeded F2 is heterozygous, like the parents?

Yellow could be GG or Gg, 2/3

What does a normal distribution represent?

A binomial distribution depicting all of the experimental outcomes

What is Chi-square (X2) analysis?

A method to statistically evaluate the relationship between observed and expected values; are the results statistically significant?

What factor does Chi-square analysis depend on?

Sample size, number of outcome classes, number of observations in each class.

What is the transmission of genes that are carried on autosomes (non-sex chromosomes) called?

Autosomal inheritance

What are pedigree analysis?

Symbolic representations of family trees; help to interpret inheritance patterns in diploid organisms.

In pedigree analysis, what is a prediction for autosomal recessive inheritance?

Affected offspring can often be born to parents that are both unaffected