question

If a homozygous dominant is crossed with a homozygous recessive for a given trait, the offspring will be ____

answer

all of the dominant phenotype

question

Which of the following is used to define a phenotypic characteristic resulting from the expression of two or more genes?

answer

polygenic inheritance

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Tay Sachs disease runs in Rebecca's family. When she looked at her family pedigree, she saw a shaded circle. This represented ____

answer

a female with Tay Sachs

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Human males are much more likely than human females to have the recessive condition hemophilia (a failure of the blood to clot properly). This is the case because __________.

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the gene for hemophilia is sex-linked

question

Assume tall (T) is dominant to dwarf (t). If a homozygous dominant individual is crossed with a homozygous dwarf, the offspring will __

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all be tall

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A genetic disorder that causes red blood cells to assume an unusual shape and produce abnormal hemoglobin proteins is _____.

answer

sickle-cell disease

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Flower color in snapdragons is an example of incomplete dominance. If a red-flowered plant is crossed with a white-flowered plant, the F1 generation has pink flowers. If a pink-flowered plant is crossed with a pink-flowered plant, the progeny plants will be _______

answer

25% red, 50% pink, and 25% white

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Cystic fibrosis can be inherited even if neither parent has the disease. This is because the disease __

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is caused by a recessive allele

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The most common phenotype in a natural population is referred to as the _

answer

wild type

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An allele is __

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an alternative version of a gene

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A single allele that controls more than one character is ___

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pleiotropic

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The physical traits of an organism are called its __

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phenotype

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Which of the following matings can produce a child with blood type AB? The letters refer to blood types (phenotypes).

answer

A x B

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Phenylketonuria (PKU) is an autosomal recessive disorder. Using P and p to represent the alleles, what is the genotype of a phenylketonuric person?

answer

pp

question

Why is it that men are responsible for the gender of their children?

answer

Unlike women, who only contribute an X chromosome, men contribute either an X or a Y chromosome.

question

In a certain plant, the alleles A, B, and C are dominant to the alleles a, b, and c. A plant with the genotype AABbcc will have the same phenotype as the plant with the genotype __

answer

AaBBcc

question

A man who has type B blood and a woman who has type A blood could have children of which of the following phenotypes?

answer

A, B, AB, or O

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Pea plants are tall if they have the genotype TT or Tt, and they are short if they have the genotype tt. A tall plant is mated with a short plant. Half the offspring are tall, and half are short. This allows us to conclude that the tall plant is ___

answer

heterozygous

question

Huntington's disease is due to an autosomal dominant allele. If a heterozygous male marries a normal female, what percentage of the offspring will have Huntington's?

answer

50%

question

If two genes are linked ____

answer

they are on the same chromosome

question

In Mendel's monohybrid cross of purple-flowered and white-flowered peas, all members of the F1 generation were of the _____ phenotype because their genotype was _____ for the flower-color gene.

answer

purple-flowered ... heterozygous

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The scientific study of heredity is called

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genetics

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Which of the following statements is correct?

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Offspring of two different true-breeding varieties are called hybrids.

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The physical traits of an organism are called its

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phenotype

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A plant with the genotype AABbcc is __________.

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homozygous for two different genes

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GgTt pea plants can produce _____ type(s) of gamete(s), but a ggtt plant can produce _____ type(s) of gamete(s

answer

four ... one

question

Which of the following is a true statement?

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A testcross is a mating between an individual with a dominant phenotype (but unknown genotype) and a homozygous recessive individual.

question

In a dihybrid cross, what is the probability of getting the genotype aa when you cross genotypes Aa and aa?

answer

1/2

question

The most common lethal genetic disease in the United States is _

answer

cystic fibrosis

question

An important technique that helps provide insight into interesting genetic questions at the molecular level, such as reasons for hairless dogs, is called __

answer

DNA sequencing

question

You cross a true-breeding red-flowered snapdragon with a true-breeding white-flowered snapdragon. All of the F1 are pink. What can you say about the alleles for the parental traits?

answer

Red and white show incomplete dominance.

question

Incomplete dominance is a condition in plants and people where _______

answer

offspring have an appearance in between the phenotypes of the two parents

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The ABO blood group in humans is an example of __________ producing four phenotypes

answer

multiple alleles

question

Which of the following is used to define a phenotypic characteristic resulting from the expression of two or more genes?

answer

polygenic inheritance

question

Although our environment can affect our phenotypic characters, __________.

answer

the effects of our environment are not passed on to the next generation

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Linked genes are genes that ________

answer

are on the same chromosome

question

Assume you were studying two characteristics of peas and when you crossed heterozygous F1 individuals you did not see the 9:3:3:1 ratio predicted for a dihybrid cross. You later found that these two characteristics were on the same chromosome. With this information, how would you explain the results

answer

The genes are linked and are inherited together.

question

The percentage of recombinant phenotypes resulting from fertilization involving recombinant gametes is called __

answer

recombination frequency

question

In general, the frequency with which crossing over occurs between two linked genes depends on ____

answer

how far apart they are on the chromosome

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Using recombination data, it is possible to determine the location of genes on a chromosome. The result is _

answer

a linkage map

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The sex chromosomes in humans that make an individual a male are _

answer

X and Y

question

In humans, the __________ determines the sex of the offspring because _________

answer

male ... the male can contribute either an X or a Y chromosome

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A gene that is located on a sex chromosome (X or Y chromosome) is ____

answer

A sex-linked gene

question

Human males are much more likely than human females to have the recessive condition hemophilia (a failure of the blood to clot properly). This is the case because

answer

the gene for hemophilia is sex-linked

question

Modern advances in __________ have provided important insights into the evolutionary history of life on Earth.

answer

technology

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