Genetics Warm Up 2
I would like to welcome you to the electronic classroom for biology and life sciences of the 21st century. Todays, geneticists rely on Gregory Mendel's work to predict the likely outcome of genetic crosses. This instrument will test your knowledge of vocabulary and principles to solve genetic problems.
As "fill-in" questions appear in this test, please enter your answers using all lower case letters. Unless, the question has printed a different set of instructions.
I wish you good luck and make high marks on the test!
Questions and Answers
- 1.
Mendel obtained plant that were true-breeding for particular traits by...
- A.
Growing plants from seed of other plants that displayed traits.
- B.
Discarding plants that showed other traits.
- C.
Allowing plants to self-pollinate for several generations.
- D.
Allowing plants to cross-pollinate for several generations.
- E.
Allowing plants to self-pollinate for one generation.
Correct Answer
C. Allowing plants to self-pollinate for several generations.Explanation
Mendel obtained plants that were true-breeding for particular traits by allowing plants to self-pollinate for several generations. This process ensured that the offspring inherited the same traits as the parent plants, resulting in plants that were consistently true-breeding for those traits. By allowing self-pollination for multiple generations, Mendel could establish a stable line of plants with the desired traits.Rate this question:
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- 2.
When Mendel crossed a strain of tall pea plants with a strain of short pea plants, he observed that all of the plant in the F1 generation were tall. This suggests that...
- A.
A tall trait was controlled by a dominant factor
- B.
A short trait was controlled by a dominant factor
- C.
Both traits were controlled by a recessive factor
- D.
Strain of short plants was not capable of pollinating tall plants
Correct Answer
A. A tall trait was controlled by a dominant factorExplanation
When Mendel crossed a strain of tall pea plants with a strain of short pea plants and observed that all of the plants in the F1 generation were tall, it suggests that the tall trait was controlled by a dominant factor. This means that the allele for tall plants is dominant over the allele for short plants. Since all the plants in the F1 generation were tall, it indicates that the dominant allele for tallness masked the presence of the recessive allele for shortness in this generation.Rate this question:
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- 3.
The F1 generation consists of the offspring of a cross between...
- A.
One parent and one offspring
- B.
One parent and F2 offspring
- C.
Two parents
- D.
Two parents and one F1 offspring
Correct Answer
C. Two parentsExplanation
The F1 generation refers to the first generation of offspring resulting from a cross between two parents. This means that the correct answer is "two parents" because the F1 generation is produced by mating two individuals from different parental lines.Rate this question:
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- 4.
A cross between pure-breeding green-podded pea plant and a homozygous yellow-pod pea plant produces only green-podded plants. When the F1 generation is allow to self-pollinate, the F2 generation consists of:
- A.
Only green-podded plants
- B.
Only yellow-podded plants
- C.
75% yellow-podded plants and 25% green-podded plants
- D.
75% green-podded plants and 25% yellow-podded plants
- E.
50% yellow-podded plants and 50% green-podded plants
- F.
85% light green podded plants and 15% dark green podded plants
Correct Answer
D. 75% green-podded plants and 25% yellow-podded plantsExplanation
The given answer suggests that the F2 generation consists of 75% green-podded plants and 25% yellow-podded plants. This can be explained by understanding the principles of Mendelian genetics. When pure-breeding green-podded pea plants are crossed with homozygous yellow-podded pea plants, the F1 generation will all be heterozygous for pod color (Gg). Since green is dominant over yellow, all the F1 plants will have green pods. When the F1 generation self-pollinates, the possible genotypes in the F2 generation are GG, Gg, and gg. The genotype GG will result in green pods, Gg will also result in green pods due to the dominance of green, and gg will result in yellow pods. Therefore, 75% of the F2 plants will have green pods (GG and Gg) and 25% will have yellow pods (gg).Rate this question:
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- 5.
The appearance of an organism is called_____.
- A.
Genotype
- B.
Phenotype
- C.
Genotypic ratio
- D.
Phenotypic ratio
- E.
Homozygous phenotype
- F.
Heterozygous genotype
Correct Answer
B. PhenotypeExplanation
The appearance of an organism is called its phenotype. This refers to the observable characteristics or traits of an organism, such as its physical features, behavior, or any other observable traits. The phenotype is determined by the interaction between an organism's genotype (its genetic makeup) and its environment. It is the result of the expression of specific genes and their interaction with the environment during development.Rate this question:
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- 6.
_____ is the passing of traits from parents to their offspring.
- A.
Heredity
- B.
Genetics
- C.
Alleles
- D.
Law of Segregation
- E.
Monohybrid Cross
Correct Answer
A. HeredityExplanation
Heredity is the correct answer because it refers to the passing of traits from parents to their offspring. It involves the transmission of genetic information from one generation to the next, determining the characteristics and traits that an individual inherits from their parents. Heredity is a fundamental concept in biology and plays a crucial role in understanding how traits are passed down through generations.Rate this question:
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- 7.
Genetics is the branch of biology that studies heredity.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Genetics is indeed the branch of biology that focuses on the study of heredity. It involves the examination of genes, DNA, and how traits are passed down from one generation to another. By studying genetics, scientists can better understand how traits and characteristics are inherited and can potentially predict and prevent certain genetic diseases. Therefore, the statement "Genetics is the branch of biology that studies heredity" is true.Rate this question:
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- 8.
_____ _____ is a cross that considers one pair of contrasting traits.
- A.
Monohybrid cross
- B.
Dihybrid Cross
- C.
Trihybrid Cross
- D.
Incomplete Cross
- E.
Allele Cross
Correct Answer
A. Monohybrid crossExplanation
A monohybrid cross is a type of genetic cross that involves the study of one pair of contrasting traits. It focuses on the inheritance of a single characteristic or gene. In this type of cross, the parents differ in only one trait, such as flower color or seed shape. By studying the offspring of this cross, scientists can determine how the trait is inherited and understand the principles of Mendelian genetics.Rate this question:
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- 9.
_____ occurrs when all the offspring display only one form of a particular trait.
- A.
Heredity
- B.
True-breeding
- C.
Cross-breeding
- D.
Codominance breeding
Correct Answer
B. True-breedingExplanation
True-breeding occurs when all the offspring display only one form of a particular trait. This means that when two true-breeding individuals with the same form of a trait are crossed, their offspring will also have the same form of the trait. True-breeding is a result of homozygosity, where both alleles for a specific trait are the same. This ensures that the trait will be consistently passed down from generation to generation without any variation.Rate this question:
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- 10.
_____ is the first two individuals crossed in a breeding experiment.
- A.
F 1 Generation
- B.
F 2 Generation
- C.
P Generation
- D.
F Generation
- E.
O Generation
Correct Answer
C. P GenerationExplanation
The P generation refers to the parental generation in a breeding experiment, where the first two individuals are crossed to produce offspring. This generation is crucial as it sets the foundation for subsequent generations and determines the inheritance patterns of traits. The P generation is often used to establish the genotype and phenotype of the parent individuals and to study the transmission of traits to the offspring in subsequent generations.Rate this question:
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- 11.
F 2, generation is the offspring of the P generation.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
The F2 generation is not the offspring of the P generation. The F2 generation is actually the result of crossing two individuals from the F1 generation, which is the offspring of the P generation.Rate this question:
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- 12.
F 1, generation is the offspring of the P generation.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The F1 generation refers to the first filial generation, which is the offspring of the parental (P) generation. It is formed through the process of sexual reproduction, where genetic material from both parents is combined to create a new generation. Therefore, the statement that the F1 generation is the offspring of the P generation is true.Rate this question:
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- 13.
F 2, generation is the offspring of the F 1 generation.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The F2 generation is indeed the offspring of the F1 generation. In genetics, F1 refers to the first filial generation, which is the result of crossing two parental generations. The F2 generation is then produced by crossing individuals from the F1 generation. This allows for the observation of genetic traits and variations in subsequent generations. So, the statement is true.Rate this question:
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- 14.
_____ are different versions of a gene.
- A.
Alleles
- B.
Phenotype
- C.
Dominant
- D.
Incomplete dominance
- E.
Heredity
Correct Answer
A. AllelesExplanation
Alleles are different versions of a gene. Genes are segments of DNA that contain instructions for the development and functioning of an organism. Alleles are alternative forms of a gene that can occupy the same locus or position on a chromosome. They can vary in their nucleotide sequence, resulting in different traits or characteristics. Alleles can be dominant or recessive, and they determine the phenotype or physical appearance of an organism. In summary, alleles are the different versions of a gene that contribute to genetic diversity and determine the traits of an organism.Rate this question:
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- 15.
_____ is a factor (gene) that masks or covers another form of a trait.
- A.
Dominant
- B.
Recessive
- C.
Allele condition
- D.
Monohybrid Cross
- E.
Self-Pollination
Correct Answer
A. DominantExplanation
In genetics, a dominant gene is one that is expressed and masks the presence of another form of a trait, known as a recessive gene. This means that if an individual has one copy of the dominant gene, it will be expressed in their phenotype, regardless of whether they also have a copy of the recessive gene. The dominant gene "dominates" over the recessive gene, hence the name. Therefore, the correct answer is Dominant.Rate this question:
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- 16.
_____ traits are not expressed when the dominant form of the trait is present.
- A.
Genotype
- B.
Recessive
- C.
Phenotype
- D.
Law of independent assortment
Explanation
Recessive traits are not expressed when the dominant form of the trait is present. This is because recessive traits require both alleles to be recessive in order to be expressed. In the presence of a dominant allele, the dominant form of the trait will be expressed instead. Genotype refers to the combination of alleles an individual possesses, while phenotype refers to the physical expression of traits. The Law of Independent Assortment states that different traits are inherited independently of each other.Rate this question:
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- 17.
Calculate the ratio of pod color using 428 green pods and 152 yellow pods.
- A.
2.84 : 1
- B.
2.81 : 2
- C.
3.01 : 1
- D.
2.81 : 1
- E.
3.14 : 1
Correct Answer
D. 2.81 : 1Explanation
The given question asks to calculate the ratio of pod color using 428 green pods and 152 yellow pods. The correct answer is 2.81:1. This means that for every 2.81 green pods, there is 1 yellow pod. This ratio can be simplified further if needed.Rate this question:
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- 18.
Calculate the ratio of flower color using 705 purple flowers and 224 white flowers.
- A.
2.84 : 1
- B.
2.81 : 2
- C.
3.01 : 1
- D.
2.81 : 1
- E.
3.15 : 1
Correct Answer
E. 3.15 : 1Explanation
The ratio of flower color can be calculated by dividing the number of purple flowers by the number of white flowers. In this case, there are 705 purple flowers and 224 white flowers. Therefore, the ratio is 705/224, which simplifies to approximately 3.15 : 1.Rate this question:
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- 19.
What is the name of the diagram that predicts the outcomes of a genetic cross?
- A.
Molecular Genetics
- B.
Mendel's Square
- C.
Punnett Square
- D.
Genotypic Ratio Square
Correct Answer
C. Punnett SquareExplanation
A Punnett Square is a diagram used in genetics to predict the outcomes of a genetic cross. It is named after Reginald Punnett, a British geneticist, who developed this tool in the early 20th century. The Punnett Square allows scientists to visualize the possible combinations of alleles from the parents and determine the probability of different genotypes and phenotypes in the offspring. It is a valuable tool in understanding and studying inheritance patterns and genetic traits.Rate this question:
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- 20.
Please choose the correct homozygous genotype for Pisum sativum L.
- A.
[TT]
- B.
[Tt]
- C.
[GGg]
- D.
[PPpp]
Correct Answer
A. [TT]Explanation
The correct homozygous genotype for Pisum sativum L. is [TT]. This means that both alleles for the trait in question are the same, in this case, both alleles are "T". Homozygous genotypes are often referred to as purebred or true-breeding because they will always produce offspring with the same trait.Rate this question:
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- 21.
_____, when the two alleles of a particular gene are the same.
- A.
Genotype
- B.
Phenotype
- C.
Dominant
- D.
Homozygous
- E.
Heterozygous
- F.
Recessive
Correct Answer
D. HomozygousExplanation
Homozygous refers to a condition where an individual has two identical alleles for a particular gene. In this case, when the two alleles of a particular gene are the same, it means that the individual is homozygous for that gene.Rate this question:
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- 22.
_____, when the two alleles of a particular gene are the different.
- A.
Genotype
- B.
Phenotype
- C.
Dominant
- D.
Homozygous
- E.
Heterozygous
- F.
Recessive
Correct Answer
E. HeterozygousExplanation
Heterozygous refers to the condition when an individual carries two different alleles of a particular gene. This means that the organism inherits one allele from each parent, resulting in a genotype that is a combination of both alleles. Heterozygosity often leads to the expression of the dominant allele in the phenotype, while the recessive allele remains hidden. Therefore, in a heterozygous genotype, the individual may not exhibit the traits associated with the recessive allele.Rate this question:
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- 23.
Genotype is a set of alleles that an individual has for a selected characteristic.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
A genotype refers to the genetic makeup of an individual, specifically the combination of alleles they possess for a particular trait. Alleles are alternative forms of a gene that determine the variations in traits. Therefore, the statement that genotype is a set of alleles that an individual has for a selected characteristic is true.Rate this question:
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- 24.
_____ is the physical appearance of an organism.
- A.
Genotype
- B.
Phenotype
- C.
Dominant
- D.
Homozygous
- E.
Heterozygous
- F.
Recessive
Correct Answer
B. PhenotypeExplanation
Phenotype refers to the physical appearance of an organism. It includes all the observable characteristics such as hair color, eye color, height, and other physical traits. The phenotype is determined by the interaction between an organism's genotype (genetic makeup) and its environment. It is the result of the expression of genes and can be influenced by factors such as nutrition, lifestyle, and exposure to external factors.Rate this question:
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- 25.
A(n)_____ _____ is a cross that considered two pairs of contrasting traits.
- A.
Monohybrid Cross
- B.
Molecule Cross
- C.
Genotypic Ratio Cross
- D.
Dihybrid Cross
- E.
Phenotypic Cross
Correct Answer
D. Dihybrid CrossExplanation
A dihybrid cross is a cross that considers two pairs of contrasting traits. In this type of cross, the parental organisms differ in two traits, and the offspring will inherit alleles for both traits from each parent. This allows for the examination of the inheritance patterns of two different traits simultaneously.Rate this question:
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