Pea plant height the cross would be dd x dd or dd x

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pea plant height the cross would be Dd x DD or Dd x dd; most often, though a backcross is a cross to a fully recessive parent Testcross - the cross of any individual to a homozygous recessive parent; used to determine if the individual is homozygous dominant or heterozygous So far, all the discussion has concentrated on monohybrid crosses. Monohybrid cross - a cross between parents that differ at a single gene pair (usually AA x aa )
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Monohybrid - the offspring of two parents that are homozygous for alternate alleles of a gene pair Remember --- a monohybrid cross is not the cross of two monohybrids. Monohybrids are good for describing the relationship between alleles. When an allele is homozygous it will show its phenotype. It is the phenotype of the heterozygote which permits us to determine the relationship of the alleles. Dominance - the ability of one allele to express its phenotype at the expense of an alternate allele; the major form of interaction between alleles; generally the dominant allele will make a gene product that the recessive cannot; therefore the dominant allele will express itself whenever it is present . Human Inheritance Even though controlled genetic experiments are not conducted to determine human inheritance, tracing family histories has allowed us to determine human inheritance for some physical features and physiological characteristics. We will explore the inheritance of some dominant-recessive traits in humans including the inheritance of blood types. Working with a lab partner (a friend) you will determine if you possess the following characteristics: U-shaped tongue, widow’s peak, free earlobe, bent little finger, finger hair, hitchhiker’s thumb and interlocking fingers. This procedure will indicate your phenotype and your possible genotype(s). The phenotype is expressed in words describing the characteristic present. The genotype is expressed in a shorthand form using letters to indicate the alleles present for each trait. For a given trait, the same letter is used twice (because alleles occur in pairs). In the case of dominant-recessive inheritance, a capital letter is used to indicate the presence of the dominant allele; and a small letter to indicate the presence of a recessive allele. For example, the dominant allele for brown eye color could be represented by “B” and the recessive allele for blue eye color could be represented by “b”. U-Shaped Tongue The ability to roll the tongue into a trough-like shape when extending it from the mouth is controlled by a dominant allele.
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