Scientists sometimes take a gene from jellyfish that encodes Green Fluorescent Protein and transfer it into mice. The jellyfish gene 'works' in mice because...

All known organisms share a common coding system for their genomic information. The common features of heredity imply that...

With respect to learning about human genetics and biology, different model organisms are useful for different kinds of genetics studies. Which of the following is most important in explaining why a species is an appropriate model organism for a particular study?

_______ organisms share a common evolutionary history with humans. The most important consideration behind choice of a species as a model organism to study a particular genetic mechanism is ___________

a pair of homologous chromosomes...

When does a chromosome consist of two sister chromatids?

Of the following stages of meiosis, which is the earliest one in which a cell is haploid through the entire phase?

during meiosis, the DNA duplication produces...

For the cross Aabbcc x AaBbCc, what fraction of the offspring are expected to have the phenotype Abc?

In Mendel's peas, tall (T) is dominant to short (t), and purple flowers (P) are dominant to white flowers (p). You cross a tall, purple-flowered plant to a short, white-flowered plant and obtain 24 tall, purple-flowered and 21 tall, white-flowered offspring. Which of the following is true?

The cross was TtPp x ttpp

Typical phenotypic ratio for a dihybrid cross...

The primary driving force responsible for the evolution of X-inactivation in mammals was the need...

In Drosophila, "sable body" is a recessive X-linked trait. A heterozygous female is crossed to a sable-bodied (affected) male. What fraction of female offspring will be affected (sable-bodied)?

In a flowering plant, AA and Aa individuals are normally 12" tall, and aa individuals are 6" tall. But if the plant has the genotype bb, the plant is 3" tall, regardless of the A-locus genotype. In terms of the types of non-Mendelian effects we have discussed in class, this is most likely an example of...

Flower color in a plant you are studying is produced through a series of enzymatic reactions. In one step, controlled by the P locus, a yellow pigment is altered to be pink. There is a recessive p allele at that locus and the yellow-to-pink alteration is not made. Individuals with the pp genotype have yellow flowers. In the next step, controlled by the R locus, the dominant trait modifies the pink pigment to be a deep red. All individuals who have the pp genotype have yellow flowers, because there is no pink pigment.

If you perform a PpRr x PpRr dihybrid cross, what do you expect the offspring phenotype ratio to be for red:pink:yellow flowers?

The red pigment required for red flower color in a plant is produced by a pathway of two enzymes. Enzyme A converts a precursor into a colorless intermediate, then Enzyme B converts the intermediate compound into red pigment. At the molecular level, the a allele produces a non-functional form of Enzyme A, and the b allele produces a non-functional form of Enzyme B. These two genes together exhibit Duplicate Recessive epistasis, and show a 9:7 phenotype ratio in a dihybrid cross.

Which of the following explains why a plant could have full Enzyme B activity (from a BB genotype), and yet produce only white flowers?

co-dominance is...

A trait can be classified as definitely dominant if