Exam 13: Observing Patterns in Inherited Traits

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

In sweet peas,dominant alleles C and P are necessary for colored flowers.In the absence of either (__ pp or cc __)or both (cc pp),the flowers are white.What the phenotypic ratios be for the cross of Cc pp x cc Pp?  

Figure 13.6 -Using the accompanying illustration and the assumption that half of a plant's sperm and eggs are p and half are P,one can predict that the chance of sperm p meeting egg P at fertilization is ____.  

In a certain breed of chicken,an incompletely dominant gene controls color.The homozygous black (BB),when crossed with the homozygous splashed-white (bb),produces an intermediate gray color pattern referred to as blue.A second gene controls the shape of the comb.The dominant allele (R)produces rose,whereas the recessive allele (r)produces single.A cross between a true-breeding black with a single comb and a true-breeding splashed-white with a rose comb will produce a total of _______ different phenotypes in the F2 generation.

In the classic argument of 'nature vs.nurture,' nature would most correspond with  

An individual with a genetic makeup of aa BB is called  

True-breeding yellow guinea pigs crossed with true-breeding white ones produce only cream-colored offspring.This pattern indicates incomplete dominance.Rough hair is found to be dominant to smooth hair.Select the F1 genotypic and phenotypic ratios of a cross between a smooth,white guinea pig with a homozygous,rough,yellow guinea pig from the following choices.  

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).Give the phenotypic results of a cross of Rr Pp x rr Pp  

Which of the following is a form of polygenic inheritance in which the effect of an allele on a trait masks the effect of a different gene?  

Which of the following diagrams is used to predict the genotypic and phenotypic outcome of a cross?  

Mendel's dihybrid crosses,but not his monohybrid crosses,show that  

The most accurate description of an organism with genotype AaBb is  

Congenital deafness in humans is due to the homozygous condition of either of the recessive alleles d or e,or both.Both dominant D and E are necessary for normal hearing.Gene D/d affects the middle ear,while gene E/e affects the inner ear.It does not matter how good the normal inner ear (as indicated by E__)is; if there is something wrong in the middle ear,the individual is unable to hear.The same applies for the other gene.What is the phenotypic result of the cross Dd EE x Dd EE?  

In horses,there are four alleles at the A locus.Arranged in dominance sequence,they are A (wild),a^b (bay),a^c (brown),a^d (black) If you bred several bay mares whose sires were brown to a brown stallion whose sire was black,what are the genotypes of the parents; what type of offspring would be produced; and in what proportion?

Which of the following is an example of incomplete dominance?  

An individual that has two dominant alleles for a trait (AA)is called __________.

A bell-shaped curve of phenotypic variation is indicative of  

In humans,normal skin pigmentation is influenced by a dominant gene (C),which allows pigmentation to develop.All individuals who are homozygous for the recessive allele (c)are unable to produce an enzyme needed for melanin formation and are therefore referred to as albino.Two normal parents produce an albino child.What are the chances that the next child will be an albino?  

The gene for human ABO blood type,for which three or more alleles persist in a population at a relatively high frequency,is an example of _______.  

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.What would be the genotype for the two normal children?