Patterns Of Inheritance - Principles of Biology

In dogs,there is a hereditary deafness caused by a recessive allele,d.A kennel owner has a male dog that she wants to use for breeding purposes if possible.The dog can hear,but the owner is unsure of the genotype.She does a testcross (crosses it to a homozygous recessive dog),and two of the five offspring are deaf.This means that the male dog

A)has the genotype Dd
B)has the genotype DD
C)has the genotype dd
D)is actually deaf
E)is still of unknown genotype since there were offspring of both deaf and hearing phenotypes

Answer

Question 2

(Multiple Choice)

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Eyelash length is an inherited trait.In the human population,there is an eyelash length gene.There are two possible variants of this gene - an allele for long eyelashes (> 1cm)and an allele for short eyelashes (1 cm or less).The allele for long eyelashes is dominant (L)and the allele for short eyelashes is recessive (l).An individual who is heterozygous for eyelash length would have which of the following phenotypes?

A)ll
B)LL
C)Ll
D)Long eyelashes
E)Short eyelashes

Answer

Question 3

(Multiple Choice)

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The single-factor crosses performed by Mendel support the observation that

A)the two alleles for a given gene are distributed randomly among an individual's gametes.
B)the two alleles for a given gene are found within the same gamete.
C)if the recessive alleles for two different genes are on the same chromosome,they will never be found within the same gamete.
D)only the dominant alleles for a given trait are found in an organism's gametes.
E)if the dominant alleles for two different genes are on different chromosomes,they will never be found within the same gametE.

Answer