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BIO 120-Mendel
BC- Mendel & the Gene Idea
| Question | Answer |
|---|---|
| Using the letter e, what would be the genotype for heterozygous? | Ee |
| The term for two genes on homologous chromosomes. | Gene Pair |
| The term for the physical manifestation of the genes, or the appearance of the organism. | Phenotype |
| Consider that round seeds (R) are dominant to wrinkled seeds (r); also, that tall (T) plants are dominant over short plants (t). Cross RRTT x rrtt and determine the phenotypic ratio of the offspring. | 100% Round and Tall |
| Using the letter e, what would be the genotype for homozygous dominant? | EE |
| Consider that tall is dominant and represented by T, and short is recessive and represented by t....what is the phenotype for the homozygous dominant genotype? | Tall |
| Suppose you observe the dominant phenotype in an organism, what two possible genotypes could code for this apperance? | Homozygous dominant and heterozygous |
| The location of a gene on a chromosome is called: | Locus |
| Alternative forms of the same gene. | Alleles |
| Consider that tall is dominant and represented by T, and short is recessive and represented by t... what would be the genotypic ratio of the offspring if you crossed: homozygous dominant with homozygous recessive? | 100% Tt |
| The results of a test cross reveal that all the offspring are tall. What was the genotype of the unknown parent? (Assume dominant is tall, recessive is short.) | TT |
| What are the abbreviations for parental generation, then the offspring and then their offspring? | P, F1, F2 |
| When an allele is able to mask or hide the effect of a second allele. | Dominance |
| When an allele can be hidden or masked by a second allele, it is said to be _______. | Recessive |
| Consider that tall is dominant and represented by T, and short is recessive and represented by t... what would be the phenotypic ratio of the offspring if you crossed: heterozygous with heterozygous? | 75% Tall, 25% short |
| Dihybrid crosses involve the crossing of ______ (how many traits)? | Two |
| Sickle cell disease (anemia) is an example of this effect wherein one gene is responsible for a multitude of symptoms in an illness. | Pleiotrophy |
| A unit of hereditary material in the DNA, producing a certain trait in an individual. | Gene |
| Consider that tall is dominant and represented by T, and short is recessive and represented by t... what would be the genotypic ratio of the offspring if you crossed: heterozygous with heterozygous? | 25%TT, 25% tt, 50% Tt |
| Consider that blue flowers are dominant and represented by B, and pink flowers are recessive and represented by b..... what would be the phenotypic ratio of the offspring if you crossed: homozygous recessive with heterozygous? | 50% Blue, 50% pink |
| The expression of a gene at one locus alters the phenotypic expression of a gene at a second locus. | Epistasis |
| Consider that round seeds (R) are dominant to wrinkled seeds (r); also, that tall (T) plants are dominant over short plants (t). Cross rrtt x RrTT and determine the phenotypic ratio of the offspring. | 50% Round and Tall & 50% wrinkled and tall |
| A test cross must be performed. You cross the unknown genotype with a known _______ individual. | Homozygous recessive |
| Consider that blue flowers are dominant and represented by B, and pink flowers are recessive and represented by b..... what would be the phenotypic ratio of the offspring if you crossed: homozygous dominant with heterozygous? | 100% Blue Flowers |
| Consider that tall is dominant and represented by T, and short is recessive and represented by t... what would be the phenotypic ratio of the offspring if you crossed: homozygous dominant with homozygous recessive? | 100% Tall |
| The name of the genetic relationship which occurs when the phenotype is intermediate between the two traits. | Incomplete Dominance |
| Consider that round seeds (R) are dominant to wrinkled seeds (r); also, that tall (T) plants are dominant over short plants (t). Cross RrTt x RrTt and determine the phenotypic ratio of the offspring. | 9 Round & Tall, 3 Round and short, 3 wrinkled and tall, 1 wrinkled and short |
| Alleles that are both expressed in the heterozygote (such as blood type). | Codominance |
| Consider that tall is dominant and represented by T, and short is recessive and represented by t....what is the phenotype for the homozygous recessive genotype? | Short |
| This rule states that a gene pair assorts independently of another gene pair (when not on homologous chromosomes). | Mendelian Principle of Independent Assortment |
| The actual genetic makeup of an organism. | Genotype |
| The results of a test cross reveal that half the offspring have the recessive phenotype and the other half are dominant. What was the genotype of the unknown parent? (Assume dominant is tall, recessive is short.) | Tt |
| This law states that only one allele specifying a trait can be carried on a single gamete, and therefore gene pairs are split during meiosis. | Law of Segregation |
| Using the letter e, what would be the genotype for homozygous recessive? | ee |
| Consider that blue flowers are dominant and represented by B, and pink flowers are recessive and represented by b..... what would be the genotypic ratio of the offspring if you crossed: homozygous dominant with heterozygous? | 50% BB, 50% Bb |
| Consider that tall is dominant and represented by T, and short is recessive and represented by t....what is the phenotype for the heterozygous genotype? Would they be half tall and half short? | No, all tall |
| When a gene has multiple phenotypic effects. | Pleiotrophy |
| This occurs when phenotypes of the heterozygote and dominant homozygote are identical | Complete dominance |
| This occurs when a trait has more than two alleles. | Multiple alleles |
| This is an example of multiple alleles: | Blood type in humans |