AP Bio Unit 5 - Topics 4, 5, and 6

Non-Mendelian Genetics

Traits that do not follow the ratios predicted by Mendel's laws.

Degrees of Dominance

Variation in the dominance of alleles, including complete dominance, incomplete dominance, and codominance.

Incomplete Dominance

A condition where neither allele is fully dominant, resulting in a mixed phenotype in the F1 generation.

Codominance

A condition where two alleles are both expressed in the phenotype of heterozygous individuals.

Multiple Alleles

Genes that exist in forms with 2 different alleles; as seen in human blood type

Epistasis

The interaction of multiple genes where one gene affects the expression of another.

Polygenic Inheritance

The combined effect of two or more genes influencing a single phenotype.

Sex-Linked Traits

Traits that are expressed differently in males and females, often linked to sex chromosomes.

X-Linked Genes

Genes located on the X chromosome that exhibit unique inheritance patterns.

X-Linked Disorders

Genetic disorders caused by mutations in genes on the X chromosome, affecting males more frequently.

X-Inactivation

The process by which one of the X chromosomes in females becomes inactive and forms a Barr body.

Genetic Recombination

The production of offspring with new combinations of genes, resulting from crossing over.

Linked Genes

Genes that are located nearby on the same chromosome and tend to be inherited together.

Mapping Distance

The determination of the relative position of genes on a chromosome, measured in map units.

Non-Nuclear DNA

DNA located outside the nucleus, such as in mitochondria and chloroplasts, inherited maternally.

Chi-Square Test

A statistical analysis used to compare observed and expected results.

Null Hypothesis

The hypothesis that there is no significant difference between observed and expected data.

Environmental Factors

External conditions affecting gene expression and phenotypic outcomes, leading to phenotypic plasticity.

Mutated Alleles

Altered versions of genes that can lead to genetic disorders, such as Tay-Sachs and sickle cell anemia.

Nondisjunction

The failure of chromosomes to separate properly during meiosis, leading to aneuploidy.

Karyotyping

A laboratory technique used to identify chromosomal abnormalities.

Complete Dominance

A genetic scenario where one allele fully expresses its trait over another, entirely masking its effects in a heterozygous individual.

Y-Linked Genes

Genes located on the Y chromosome that are inherited exclusively through the male lineage.

Step 1: Formulate Hypotheses

Define the null hypothesis (suggesting no significant difference) and the alternative hypothesis (suggesting a significant difference).

Step 2: Calculate the Chi-Square Statistic

Use the chi-square formula to calculate the statistic, comparing observed and expected frequencies.

Step 3: Determine Significance

Compare the calculated chi-square value to the critical value from the chi-square distribution table based on degrees of freedom and alpha level.