Variation: Phenotype The observable characteristics of an organism are its phenotype Phenotypic variation is the difference in phenotypes between organisms of the same species In some cases, phenot...
Gene Control: Transcription Factors Prokaryotes use operons to control the expression of genes in cells Eukaryotes also use transcription factors to control gene expression A transcription factor i...
Gene Control: Lac Operon Regulatory genes control structural genes and their levels of protein production Regulatory genes sometimes have control over several structural genes at once Structural ge...
Gene Control The nucleus of every cell in the human body contains the same genes However not every gene is expressed in every cell Not all of these genes are expressed all the time There are severa...
The Role of Gibberellin in Stem Elongation In some plants species their height is partially controlled by their genes The Le gene dictates the height of some plants It has two alleles: Le and le Th...
Genes, Proteins & Phenotype A gene can affect a phenotype of an organism A gene codes for a single protein The protein affects the phenotype through a particular mechanism The phenotype of an i...
Predicting Inheritance: Chi-squared Test The difference between expected and observed results in experiments can be statistically significant or insignificant (happened by chance) If the difference...
Predicting Inheritance: Test Crosses A test cross can be used to deduce the genotype of an unknown individual that is expressing a dominant phenotype The individual in question is crossed with an i...
Predicting Inheritance: Dihybrid Crosses Monohybrid crosses look at how the alleles of one gene transfer across generations Dihybrid crosses look at how the alleles of two genes transfer across gen...
