Exam 13: Observing Patterns in Inherited Traits

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color.The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p).A tall plant with purple flowers crossed with a dwarf plant with white flowers produces 1/4 tall purple, 1/4 tall white, 1/4 dwarf purple, and 1/4 dwarf white.What is the genotype of the parents?

A homozygous recessive where "A" represents the trait has two recessive alleles symbolized by __________.

If long or round are homozygous forms of an incompletely dominant gene, and oval is the phenotype of the heterozygote, give the F₂ ratio of the cross between long and round (both genotype and phenotype).

In mice the allele for colored fur (C) is dominant to the allele for albinism (c).The allele for normal behavior (W) is dominant to that for waltzing movement (w).Give the probable genotypes of the parents if they produced the offspring listed after the following crosses: (a) colored normal * white waltzer produced 10 colored normal, 8 colored waltzers, 2 white waltzers, 11 white normal (b) colored normal * white normal produced 35 colored normal, 13 colored waltzers (c) colored normal * colored normal produced 37 colored normal, 14 colored waltzers, 9 white normal, and 5 white waltzers

In poultry, the genes for rose comb (R) and pea comb (P) produce walnut whenever they occur together (R__ P__); single-combed individuals have the homozygous condition for both genes (rr pp). (a) Give the F₁ and F₂ phenotypic results of a cross of a pure-breeding rose comb (RR pp) with a pure-breeding pea comb (rr PP). (b) Give the phenotypic results of a cross of Rr Pp * rr Pp. (c) Give the phenotypic results of a cross of RR Pp * rr Pp. (d) Give the phenotypic results of a cross of Rr pp * rr Pp. (e) Give the phenotypic results of a cross of Rr Pp * rr pp.

Which of the following is NOT a known effect in the expression of Marfan syndrome?

According to Mendel, what kinds of genes "disappear" in F₁ pea plants?

The allele for albinism (c) is recessive to the allele for normal pigmentation (C).A normally pigmented woman whose father is an albino marries an albino man whose parents are normal.They have three children, two normal and one albino.Give the genotypes for each person listed.

Explain what genetic 'trick' could have confounded Mendel is his recognition of segregation?

In sweet peas, genes C and P are necessary for colored flowers.In the absence of either (__ pp or cc __) or both (cc pp), the flowers are white.Give the probable genotype of a plant with colored flowers and a plant with white flowers that produced 38 plants with colored flowers and 42 plants with white flowers.

In cultivated stocks, the cross of a variety of white flower plants produced all red flowers in the F₁ generation, but the F₂ generation produced 87 red, 31 cream, and 39 white.Explain these results by giving the genotypes possible for each phenotype.

If you were following the inheritance patterns of two different sets of multiple alleles located on different chromosomes, how many different possible gametes could be produced if locus 1 had five possible alleles and locus 2 had six alleles?

Consider the work Mendel did with his pea plants.Why is the study of human genetics much more difficult?

Different molecular forms of the same gene are __________.

Heritable units of information about traits are called __________.

For Mendel's explanation of inheritance to be correct,

The ABO blood types are controlled by

In summer squash, spherical-shaped fruit has been shown to be dominant to elongated fruit.On one occasion two different spherical varieties were crossed and produced all disk-shaped fruits.When these hybrid disk-shaped fruits were crossed, they produced 75 disk-shaped fruits, 48 spherical fruits, and 9 elongated fruits.Explain these results.

-Genes at one locus that affect the expression of genes at a different locus are said to be

In rabbits, there are four alleles at the c locus.Arranged in dominance sequence they are: C (agouti), c^ch(chinchilla), c^h(Himalayan), and c (albino) (a) Is it possible to cross two agouti rabbits and produce both chinchilla and Himalayan offspring? (b) Is it possible to cross two chinchillas and produce 1/2 chinchilla and 1/2 Himalayan?