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How to find out if a population is evolving?

By: HWC, Views: 4874

Imagine a butterfly population with a pair of alleles that influence wing color as shown. We will represent the frequency of the dominant allele as p and the recessive allele as q. The Hardy-Weinberg rule describes what happens if a population is at genetic equilibrium—if it is not evolving...

Monohybrid crosses

By: HWC, Views: 5745

A monohybrid cross is a cross between two parents that breed true for different versions of a single trait. In this example, that trait is flower color. The allele that specifies purple flowers is dominant over the allele that specifies white flowers. The purple-flowered plant has two domin...

X chromosome inactivation in calico cats

By: HWC, Views: 4814

X chromosome inactivation causes a mosaic tissue effect in calico cats. what makes this female calico cat "calico." Like all mammals, this cat began her life as a single cell. That cell had two X chromosomes, one from each parent. One of the chromosomes carried a dominant allele for the ...

Genetic terms Animation

By: HWC, Views: 2263

Diploid organisms have pairs of genes, on pairs of homologous chromosomes. Each gene has a specific location on the chromosome. We call this the gene's locus. In this species, the locus for gene B is always between the loci for genes A and C. Most genes come in two or more slightly differen...

Effect of the environment on coat color in the Himalayan rabbit Animation

By: HWC, Views: 3403

An organism's phenotype—the combination of traits that we observe—is the product of interactions between its genotype and the environment. For example. a Himalayan rabbit is completely white at birth. But within weeks, the fur on the rabbits ears, nose, tail. and lower legs darkens. The...

Mendel's Principles of Dominance, Segregation and Independent Assortment

By: HWC, Views: 7400

Mendel selected true-breeding parents with contrasting traits, for example, purple and white flower color, and performed reciprocal crosses by choosing pollen from one parent and hand pollinating the seed-forming parent with this pollen. A cross-fertilization resulted from this procedure. In t...