Genetics BVHS
Questions and Answers
- 1.
A heterozygous tall pea plant is crossed with a short plant. Tall (T) is dominant to short (t) plants. The probability that the offspring plant will be tall is:
- A.
75%
- B.
25%
- C.
50%
- D.
100%
Correct Answer
C. 50%Explanation
When a heterozygous tall pea plant (Tt) is crossed with a short plant (tt), the possible genotypes of the offspring are Tt and tt. Since tall (T) is dominant to short (t), the Tt genotype will result in a tall plant. On the other hand, the tt genotype will result in a short plant. Therefore, half of the offspring will be tall and the other half will be short. Thus, the probability that the offspring plant will be tall is 50%.Rate this question:
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- 2.
Brown (B) is dominant over white (b) in foxes. A homozygous brown fox is crossed with a white fox. The probability that the fox offspring will be white?
- A.
0
- B.
25
- C.
50
- D.
100
Correct Answer
A. 0Explanation
When a homozygous brown fox (BB) is crossed with a white fox (bb), all of the offspring will inherit one brown allele from the brown fox parent and one white allele from the white fox parent, resulting in them being heterozygous (Bb) for the brown color gene. Since brown (B) is dominant over white (b), all of the offspring will exhibit the brown phenotype, making the probability of the fox offspring being white 0%.Rate this question:
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- 3.
A heterozygous tall (Tt) plant is crossed at with a short plant (tt). The probability that offspring plants will be tall is...
- A.
25%
- B.
50%
- C.
75%
- D.
100%
Correct Answer
B. 50%Explanation
When a heterozygous tall (Tt) plant is crossed with a short plant (tt), the offspring will inherit one allele for tallness (T) and one allele for shortness (t). Since the allele for tallness (T) is dominant over the allele for shortness (t), the offspring will be tall if they inherit at least one allele for tallness (T). Therefore, there is a 50% probability that the offspring plants will be tall.Rate this question:
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- 4.
Organisms that have two different alleles for a particular trait are said to be...
- A.
Hybird
- B.
Homozygyous
- C.
Heterozygous
- D.
Dominant
Correct Answer
C. HeterozygousExplanation
Organisms that have two different alleles for a particular trait are said to be heterozygous. Heterozygous refers to the condition where an organism carries two different alleles for a specific trait, one inherited from each parent. This means that the organism has a combination of different genetic information for that particular trait. In contrast, homozygous refers to the condition where an organism carries two identical alleles for a specific trait, while hybrid refers to the offspring of two different species or varieties. Dominant, on the other hand, refers to an allele that is expressed over another allele in heterozygous individuals.Rate this question:
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- 5.
In pepper plants, the allele for hot flavor (H) is dominant to the allele for mild flavor(h). A farmer crosses a homozygous dominant plant with a recessive (mild) plant. What percentage of the offspring from this cross will have hot flavor?
- A.
25%
- B.
50%
- C.
75%
- D.
100%
Correct Answer
D. 100%Explanation
When the allele for hot flavor (H) is dominant to the allele for mild flavor (h), crossing a homozygous dominant plant (HH) with a recessive plant (hh) will result in all heterozygous offspring (Hh). Since the dominant allele for hot flavor will always be expressed in heterozygous individuals, 100% of the offspring from this cross will have hot flavor.Rate this question:
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- 6.
Which four items are living things with D.N.A.?
- A.
Water, tree, birds, soil
- B.
Animals, people, plants, bacteria
- C.
Desk, clouds, hair, yeast
- D.
Cells, bacteria, metal, fertilizer
Correct Answer
B. Animals, people, plants, bacteriaExplanation
The correct answer is animals, people, plants, bacteria. Animals, people, plants, and bacteria are all living things that possess DNA. DNA is the genetic material that carries the instructions for the development and functioning of living organisms. Water, tree, birds, soil, desk, clouds, hair, yeast, cells, bacteria, metal, and fertilizer do not possess DNA and are not living things.Rate this question:
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- 7.
If two parents are heterozygous for a genetically inherited dominant trait, what is the probability that they will have a child together who has this trait in his or her phenotype?
- A.
0%
- B.
25%
- C.
50%
- D.
75%
- E.
100%
Correct Answer
D. 75%Explanation
If both parents are heterozygous for a genetically inherited dominant trait, it means that they each carry one copy of the dominant allele and one copy of the recessive allele. When they have a child together, there is a 25% chance that the child will inherit two copies of the dominant allele and display the trait in their phenotype. This is because there is a 50% chance that the child will inherit the dominant allele from one parent, and another 50% chance that they will inherit the dominant allele from the other parent. Therefore, the probability of having a child with the dominant trait is 50% x 50% = 25%.Rate this question:
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- 8.
If a woman is homozygous normal and her husband is heterozygous for a genetically inherited recessive disease and they decide to become parents, what is the probability that they will have a healthy child?
- A.
1 of 4
- B.
2 of 4
- C.
3 of 4
- D.
4 of 4
Correct Answer
D. 4 of 4Explanation
When a woman is homozygous normal (meaning she does not carry the recessive disease allele) and her husband is heterozygous (meaning he carries one normal allele and one disease allele), there is a 100% probability (4 out of 4) that their child will inherit a normal allele from the mother and have a healthy outcome.Rate this question:
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- 9.
One cat carries heterozygous, long-haired traits (Ss), and its mate carries homozygous short-haired traits (ss). Use a Punnett square to determine the probability of one of their offspring having long hair.
- A.
0%
- B.
25%
- C.
50%
- D.
75%
- E.
100%
Correct Answer
C. 50%Explanation
When one parent carries the heterozygous long-haired trait (Ss) and the other parent carries the homozygous short-haired trait (ss), the Punnett square shows that there is a 50% chance of their offspring having long hair. This is because in the Punnett square, the possible combinations of alleles are Ss and ss. Since the S allele is dominant over the s allele, only the offspring with the genotype Ss will have long hair, while the offspring with the genotype ss will have short hair. Therefore, there is a 50% chance of the offspring inheriting the S allele and having long hair.Rate this question:
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- 10.
In a certain species of plant, the color purple (P) is dominant to the color white (p). What is the probability of an offspring being white if one parent is homologous dominant and the other homologyous recessive? Make a punnet square to determine the percentages.
- A.
0%
- B.
25%
- C.
75%
- D.
100%
Correct Answer
A. 0%Explanation
If one parent is homozygous dominant (PP) and the other is homozygous recessive (pp), all of their offspring will receive one dominant allele from the dominant parent and one recessive allele from the recessive parent. Therefore, all of the offspring will be heterozygous (Pp) and have the purple color phenotype. There will be no offspring that are homozygous recessive (pp) and have the white color phenotype. Thus, the probability of an offspring being white is 0%.Rate this question:
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- 11.
The scientist often reffered to as the father of genetics.
- A.
Albert Einstein
- B.
Gregor Mendel
- C.
Louis Pasteur
- D.
Alexander Flemming
Correct Answer
B. Gregor MendelExplanation
Gregor Mendel is often referred to as the father of genetics because of his groundbreaking work on pea plants in the 19th century. Through meticulous experiments and observations, Mendel discovered the fundamental principles of inheritance, including the concepts of dominant and recessive traits, as well as the laws of segregation and independent assortment. His work laid the foundation for modern genetics and revolutionized our understanding of how traits are passed down from one generation to the next. Mendel's discoveries were not widely recognized during his lifetime, but his work became highly influential in the field of genetics in the 20th century.Rate this question:
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- 12.
An example of a heterozygous genotype is...
- A.
Tt
- B.
Tt
- C.
TT
- D.
Tall
Correct Answer
B. TtExplanation
A heterozygous genotype refers to a condition where an individual has two different alleles for a particular gene. In this case, the genotype "Tt" represents a heterozygous condition because it has both a dominant allele (T) and a recessive allele (t) for a specific trait. This means that the individual will exhibit the dominant trait (Tall) because the dominant allele masks the expression of the recessive allele.Rate this question:
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- 13.
Blonde hair is an example of what?
- A.
Phenotype
- B.
Genotype
Correct Answer
A. PhenotypeExplanation
Blonde hair is an example of a phenotype because it is a physical trait that can be observed and is determined by the interaction between an individual's genes (genotype) and their environment. Phenotype refers to the observable characteristics of an organism, while genotype refers to the genetic makeup or the combination of alleles that an organism carries. In the case of blonde hair, the specific combination of genes responsible for hair color results in the observable phenotype of having blonde hair.Rate this question:
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- 14.
The scientific study of heredity is called...
- A.
Meiosis
- B.
Crossing Over
- C.
Genetics
- D.
Pollination
Correct Answer
C. GeneticsExplanation
The term "genetics" refers to the scientific study of heredity, which involves the understanding of how traits are passed down from one generation to another. It encompasses the study of genes, DNA, and genetic variations, as well as the mechanisms of inheritance and genetic disorders. Meiosis, crossing over, and pollination are all processes that are related to genetics, but they do not encompass the entire field of study.Rate this question:
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- 15.
In a genotype for plant height, such as Tt, what does each letter represent?
- A.
One genotype
- B.
One gene
- C.
One allele
- D.
One gamete
Correct Answer
C. One alleleExplanation
In a genotype for plant height, such as Tt, each letter represents one allele. An allele is a variant form of a gene, and in this case, the genotype Tt indicates that the plant has two different alleles for the height gene. The uppercase T represents the dominant allele, while the lowercase t represents the recessive allele.Rate this question:
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- 16.
In cats, yellow fur is dominant over white fur. A heterozygous cat is mated with a white cat. The genotypes of offspring that could occur are:
- A.
YY and Yy
- B.
Yy
- C.
Yy and yy
- D.
YY, Yy, and yy
Correct Answer
C. Yy and yyExplanation
When a heterozygous cat (Yy) is mated with a white cat (yy), the possible genotypes of the offspring are Yy and yy. This is because yellow fur (Y) is dominant over white fur (y), so even if only one yellow allele is present (Yy), the cat will have yellow fur. However, if both alleles are white (yy), the cat will have white fur. Therefore, the genotypes Yy and yy are the possible outcomes of this mating.Rate this question:
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- 17.
If two people who are both carrier(heterozygous) for a genetically inherited fatal recessive disease decide to become parents, what will be the odds that their children will also be carriers?
- A.
1 of 4
- B.
2 of 4
- C.
3 of 4
- D.
4 of 4
Correct Answer
B. 2 of 4Explanation
If both parents are carriers for a genetically inherited fatal recessive disease, there is a 50% chance that their children will also be carriers. This is because each parent has one copy of the disease-causing gene and one copy of a normal gene. When they have children, there is a 25% chance that the child will inherit the disease-causing gene from both parents and be affected by the disease, a 25% chance that the child will inherit two normal genes and not be a carrier, and a 50% chance that the child will inherit one disease-causing gene and one normal gene, making them a carrier. Therefore, the odds that their children will be carriers is 2 out of 4.Rate this question:
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- 18.
An individual is Aabb. How many different gametes can this individual create?
- A.
1
- B.
2
- C.
3
- D.
4
Correct Answer
B. 2Explanation
An individual with genotype Aabb can create two different gametes. This is because during gamete formation, the alleles for each gene segregate independently. In this case, the alleles for gene A and gene a segregate independently, resulting in two possible combinations of alleles: Aa and ab. Therefore, the individual can produce two different types of gametes.Rate this question:
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- 19.
A black rat is crossed with a brown rat. They have 14 offspring (8 black, 6 brown). What were the genotypes of the original rats?
- A.
AA x aa
- B.
Aa x Aa
- C.
AA x Aa
- D.
Aa x aa
Correct Answer
D. Aa x aaExplanation
The genotypes of the original rats were Aa and aa. This can be inferred from the fact that the offspring included both black (aa) and brown (Aa) rats. Aa is a heterozygous genotype, meaning it carries one dominant allele (A) and one recessive allele (a). The presence of both black and brown offspring suggests that one of the original rats must have carried the recessive allele (a), while the other carried the dominant allele (A) along with the recessive allele (a).Rate this question:
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- 20.
In the process of a test-cross, a purple-flowered pea (dominant) is crossed with a white-flowered pea plant. Only four offspring survive, 3 purple and 1 white. What can you say about the genotypes of the purple and white plants?
- A.
Probably AA/ aa
- B.
Probably Aa/aa
- C.
Definitely Aa/aa
- D.
Possibly Aa/Aa
Correct Answer
C. Definitely Aa/aaExplanation
The fact that both purple and white offspring were produced suggests that the purple-flowered parent must have been heterozygous (Aa) for the flower color gene, while the white-flowered parent must have been homozygous recessive (aa). This is because the purple color is dominant and the white color is recessive. Therefore, the genotypes of the purple and white plants are definitely Aa/aa.Rate this question:
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- 21.
For eye color, brown is dominant and blue is recessive.What is the genotype for a blue-eye individual?
- A.
Brown
- B.
Blue
- C.
Aa
- D.
AA
- E.
Aa
Correct Answer
E. AaExplanation
The genotype for a blue-eye individual is aa. This means that both alleles for eye color are recessive, resulting in the expression of blue eyes.Rate this question:
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- 22.
A yellow-podded pea plant is crossed with a yellow-podded pea plant. Of their offspring, 398 have yellow pods and 122 have green pods. a.What were the likely genotypes of each parent?b. What is the ratio for the offspring?
- A.
AA x Aa; .72
- B.
Aa x Aa; .72
- C.
AA x Aa; 3.3: 1
- D.
Aa x Aa; 3.3:1
Correct Answer
D. Aa x Aa; 3.3:1Explanation
The likely genotypes of each parent are Aa, as indicated by the ratio of the offspring. The ratio of 3.3:1 suggests that the offspring are exhibiting a phenotypic ratio of 3 yellow pods to 1 green pod, which is consistent with a dihybrid cross between two heterozygous individuals (Aa x Aa).Rate this question:
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- 23.
AaBb X aaBb (A =brown eyes, a= blue; B= long tail, b=short tail) fraction with blue eyes, long tail.?
- A.
0/16
- B.
1/16
- C.
3/16
- D.
6/16
- E.
8/16
- F.
9/16
Correct Answer
D. 6/16Explanation
When two individuals, AaBb and aaBb, are crossed, their offspring will have a combination of alleles from both parents. In this case, we are interested in the fraction of offspring with blue eyes and a long tail.
Out of the 16 possible combinations of alleles in the offspring, 6 of them will have the genotype aaBb, which corresponds to blue eyes and a long tail. Therefore, the fraction of offspring with blue eyes and a long tail is 6/16.Rate this question:
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- 24.
Any individual is AaBB.List all the unique gametes this individual can produce.
- A.
Aa; BB
- B.
A; a; B
- C.
AB; aB; Ab; ab
- D.
AB; aB
Correct Answer
D. AB; aBExplanation
The individual is heterozygous for two traits, A and B. Each trait has two alleles, A and a for trait A, and B and b for trait B. During gamete formation, the alleles segregate independently, resulting in four possible combinations: AB, aB, Ab, and ab. Therefore, the individual can produce the gametes AB and aB.Rate this question:
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- 25.
Aabb X aaBb (A =brown eyes, a= blue; B= long tail, b=short tail) a. % with blue eye, short tail. b. % with brown eyes, short tail.
- A.
0%; 50%
- B.
0%; 100%
- C.
25%; 75%
- D.
25%; 25%
- E.
25%; 50%
Correct Answer
D. 25%; 25%Explanation
In this question, we are given the genotype of two individuals, Aabb and aaBb, and we need to determine the percentage of offspring with certain traits. The genotype Aabb indicates that the individual has brown eyes and a short tail, while aaBb indicates blue eyes and a long tail. The lowercase letters represent recessive alleles.
When we cross these two individuals, the possible genotypes of the offspring are AaBb, Aabb, aaBb, and aabb. Out of these four possibilities, only two have the trait of brown eyes and short tail, which are Aabb and AaBb. Therefore, the percentage of offspring with blue eyes and short tail is 25%, and the percentage of offspring with brown eyes and short tail is also 25%.Rate this question:
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- 26.
AaBb X aaBb (A =brown eyes, a= blue; B= long tail, b=short tail) a. fraction with blue eyes, long tail. b. fraction with brown eyes, long tail.
- A.
0/16
- B.
1/16
- C.
3/16
- D.
6/16
- E.
8/16
- F.
9/16
Correct Answer
D. 6/16Explanation
When AaBb is crossed with aaBb, the possible combinations of alleles in the offspring are AaBb, Aabb, aaBb, and aabb. Out of these combinations, 6 out of 16 have blue eyes and a long tail, which is the fraction 6/16.Rate this question:
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- 27.
A person is blood type O. a. To which blood types can they donate? b. From which blood types can they receive?
- A.
0; All
- B.
All; 0
- C.
All but 0; AB
- D.
AB; All but AB
Correct Answer
B. All; 0Explanation
A person with blood type O can donate blood to all other blood types (A, B, AB, and O) because their blood does not have A or B antigens on the red blood cells. However, they can only receive blood from other individuals with blood type O because they have antibodies against A and B antigens in their blood plasma.Rate this question:
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- 28.
A person is blood type B. A. To which blood types can he donate to? B. From which blood types can they receive?
- A.
AB; All but AB
- B.
O & B; B and AB
- C.
A & B; B & O
- D.
B & AB; B & 0
Correct Answer
D. B & AB; B & 0Explanation
A person with blood type B can donate blood to individuals with blood types B and AB because they have the B antigen on their red blood cells. They can receive blood from individuals with blood types B and O because they do not have the A antigen on their red blood cells, which could cause an immune response.Rate this question:
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- 29.
Mom is blood type A (IAi) and dad is blood type O. What are the possible blood types of their children and probability of each?
- A.
A 50%; O 50%
- B.
AO 100%
- C.
A 25%; B 25%; O 50%
- D.
A 100%
Correct Answer
A. A 50%; O 50%Explanation
Since the mother is blood type A (IAi) and the father is blood type O, their children can inherit either the A allele or the O allele from the mother, and the O allele from the father. Therefore, there are two possible blood types for their children: A and O. The probability of each blood type is 50% for A and 50% for O.Rate this question:
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- 30.
A woman is a carrier and her husband is not color blind. a. % of sons with normal vision? b. % of daughters with normal vision?
- A.
A. 100 % b. 0%
- B.
A. 50% b. 50%
- C.
A. 50% b. 0%
- D.
A. 50% b. 100%
Correct Answer
B. A. 50% b. 50%Explanation
Since the woman is a carrier of color blindness and her husband is not color blind, there is a 50% chance that their sons will inherit the color blindness gene from the woman. Therefore, the percentage of sons with normal vision is 50%. Similarly, there is also a 50% chance that their daughters will inherit the color blindness gene from the woman. Therefore, the percentage of daughters with normal vision is also 50%.Rate this question:
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- 31.
A. Is this trait dominant or recessive?b. Is this trait autosomal or sex-linked?
- A.
A. Dom b. Auto
- B.
A. Dom b. Sex-linked
- C.
A. Recessive b. Auto
- D.
A. Recessive b. Sex-linked
Correct Answer
C. A. Recessive b. AutoExplanation
The given correct answer states that the trait is recessive and autosomal. This means that the trait is only expressed when an individual has two copies of the recessive allele and it is not linked to the sex chromosomes.Rate this question:
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- 32.
A. Is this trait dominant or recessive, or either?b. Is this trait autosomal, sex-linked, or either?
- A.
Recessive, Autosomal
- B.
Recessive, Either
- C.
Either, Autosomal
- D.
Either, Either
Correct Answer
A. Recessive, AutosomalExplanation
This means that the trait in question is recessive, meaning it is only expressed when an individual has two copies of the recessive allele. Additionally, the trait is autosomal, meaning it is not linked to the sex chromosomes and can be inherited by both males and females.Rate this question:
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Mar 21, 2023Quiz Edited by
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