Unit 4 Test!!!!:):):):)
Take this quiz to get that A+/100% on that upcoming Biology unit test of yours! Happy Sweeties! Study up and enjoy!:):):):)
Questions and Answers
- 1.
What is the number of chromosomes in a normal human karyotype?
- A.
2
- B.
23
- C.
44
- D.
46
Correct Answer
D. 46Explanation
A normal human karyotype consists of 46 chromosomes. Chromosomes are thread-like structures located inside the nucleus of cells that contain genetic information. These chromosomes are organized into pairs, with each pair consisting of two homologous chromosomes. In humans, there are 23 pairs of chromosomes, for a total of 46 chromosomes. This is the correct answer because it accurately represents the number of chromosomes in a normal human karyotype.Rate this question:
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- 2.
Colorblindness is more common in males than in females because the allele for colorblindness is
- A.
Dominant and located on the X chromosome!
- B.
Dominant and located on the Y chromosome!
- C.
Recessive and located on the X chromosome!
- D.
Recessive and located on the Y chromosome!
Correct Answer
C. Recessive and located on the X chromosome!Explanation
Colorblindness is more common in males than in females because the allele for colorblindness is recessive and located on the X chromosome. This means that males, who have only one X chromosome, are more likely to express the recessive allele if they inherit it. Females, on the other hand, have two X chromosomes, so they are more likely to be carriers of the recessive allele without showing the trait themselves.Rate this question:
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- 3.
The alleles for blood groups lA and lB are codominant. When paired they produce the blood type
- A.
A
- B.
B
- C.
O
- D.
AB
Correct Answer
D. ABExplanation
The alleles for blood groups lA and lB are codominant, which means that both alleles are expressed equally in the phenotype. When paired together, they produce the blood type AB. This means that individuals with this blood type have both the A and B antigens on their red blood cells.Rate this question:
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- 4.
Which of the following diseases and conditions does not appear until later in a person's life?
- A.
Cystic Fibrosis
- B.
Sickle Cell Disease
- C.
Colorblindness
- D.
Huntington's Disease
Correct Answer
D. Huntington's DiseaseExplanation
Huntington's Disease is a hereditary condition that is caused by a mutation in a person's genes. Symptoms of the disease typically do not appear until later in life, usually between the ages of 30 and 50. This is in contrast to the other options listed - Cystic Fibrosis, Sickle Cell Disease, and Colorblindness - which can all be present from birth or develop early in life.Rate this question:
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- 5.
Because two copies of a defective CF allele are needed to produce cystic fibrosis,
- A.
The CF allele is dominant!
- B.
The CF allele is recessive!
- C.
The CF allele cannot produce CFTR!
- D.
The CF allele overproduces CFTR!
Correct Answer
B. The CF allele is recessive!Explanation
The CF allele is recessive because two copies of the defective CF allele are needed to produce cystic fibrosis. This means that individuals who have only one copy of the CF allele are carriers and do not show symptoms of the disease. Only individuals who inherit two copies of the CF allele from both parents will have cystic fibrosis.Rate this question:
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- 6.
Which of the following disorders does NOT result from nondisjunction in meiosis?
- A.
Down syndrome
- B.
Turner's syndrome
- C.
Klinefelter's syndrome
- D.
Sickle cell disease
Correct Answer
D. Sickle cell diseaseExplanation
Sickle cell disease is not caused by nondisjunction in meiosis. It is a genetic disorder that results from a mutation in the hemoglobin gene, causing red blood cells to become sickle-shaped. Nondisjunction in meiosis can lead to an abnormal number of chromosomes in the resulting cells, which is the cause of Down syndrome, Turner's syndrome, and Klinefelter's syndrome.Rate this question:
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- 7.
The first step in sequencing the human genome is
- A.
Locating overlapping sequences!
- B.
Identifying genes by finding promoters!
- C.
Cutting the DNA into manageable pieces!
- D.
Sorting introns from exons!
Correct Answer
C. Cutting the DNA into manageable pieces!Explanation
Cutting the DNA into manageable pieces is the first step in sequencing the human genome because the human genome is extremely large and complex. By cutting the DNA into smaller, more manageable pieces, it becomes easier to analyze and sequence each piece individually. This process allows scientists to break down the genome into smaller fragments that can be sequenced and then reassembled to obtain the complete sequence of the genome.Rate this question:
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- 8.
What is the role of restriction enzymes in studying the human genome?
- A.
Copying pieces of DNA!
- B.
Labeling different nucleotides with chemical dyes!
- C.
Separating different pieces of DNA based on their size!
- D.
Cutting large DNA molecules into smaller pieces!
Correct Answer
D. Cutting large DNA molecules into smaller pieces!Explanation
Restriction enzymes play a crucial role in studying the human genome by cutting large DNA molecules into smaller pieces. This process, known as DNA fragmentation, allows scientists to analyze specific regions of the genome more easily. By cutting the DNA into smaller fragments, researchers can study individual genes or specific sequences of interest. This fragmentation also enables other techniques such as DNA sequencing and polymerase chain reaction (PCR) to be performed more effectively. Therefore, cutting large DNA molecules into smaller pieces is an essential step in studying the human genome.Rate this question:
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- 9.
The technique known as gel electrophoresis serves to
- A.
Bind DNA to chemical dyes!
- B.
Separate DNA fragments!
- C.
Reproduce DNA strands!
- D.
Synthesize nucleotide bases!
Correct Answer
B. Separate DNA fragments!Explanation
Gel electrophoresis is a technique used to separate DNA fragments based on their size and charge. It involves placing DNA samples on a gel matrix and applying an electric current. The negatively charged DNA fragments move towards the positive electrode, with smaller fragments moving faster and further than larger fragments. This separation allows scientists to analyze and study the DNA fragments, such as identifying genetic variations or determining the size of DNA molecules. Therefore, gel electrophoresis serves to separate DNA fragments.Rate this question:
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- 10.
A student traced the recurrence of a widow’s peak hairline in her family. Based on her interviews and observations, she drew the pedigree shown below. Which pattern of inheritance is consistent with the pedigree?
- A.
Sex-Linked
- B.
Multiple Alleles
- C.
Codominant Alleles
- D.
Dominant Alleles
Correct Answer
D. Dominant AllelesExplanation
The pedigree shows that the widow's peak hairline trait is present in every generation, which suggests that it is a dominant trait. This means that individuals only need to inherit one copy of the dominant allele to express the trait. If it were a recessive trait, it would skip generations and only appear when both parents carry and pass on the recessive allele. Sex-linked inheritance would show a different pattern, as it would be more common in one sex than the other. Multiple alleles and codominant alleles would result in more variation and different phenotypes within the family, which is not observed in the given pedigree.Rate this question:
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- 11.
Huntington’s disease is caused by a dominant allele for a protein found in brain cells. The symptoms of Huntington’s disease include mental deterioration and uncontrollable movements. Symptoms do not usually appear until middle age. How could a doctor determine the chances that a patient would have Huntington’s disease?
- A.
By identifying if the patient’s parents carry the dominant allele for Huntington’s disease!
- B.
By identifying if the patient is married to a person that exhibits symptoms of Huntington’s disease!
- C.
By identifying if the patient had been in close contact with someone that exhibits symptoms of Huntington’s disease!
- D.
By identifying if the patient had been in close contact with someone that carries the dominant allele for Huntington’s disease!
Correct Answer
A. By identifying if the patient’s parents carry the dominant allele for Huntington’s disease!Explanation
A doctor can determine the chances that a patient would have Huntington's disease by identifying if the patient's parents carry the dominant allele for the disease. Since Huntington's disease is caused by a dominant allele, if one of the patient's parents carries the allele, there is a 50% chance that the patient has inherited it as well. This information can help the doctor assess the likelihood of the patient developing the disease.Rate this question:
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- 12.
In 2008, the U.S. Congress passed the Genetic Information Nondiscrimination Act. This act makes it illegal for insurance companies and employers to discriminate based on information from genetic tests. Which of the following was most likely a concern that led to passage of the Genetic Information Nondiscrimination Act?
- A.
Insurance companies might identify where a person lives!
- B.
Insurance companies might charge unreasonable rates for genetic tests!
- C.
Insurance companies might try to alter a person’s DNA!
- D.
Insurance companies might deny a person insurance based on his or her chances of developing a disease!
Correct Answer
D. Insurance companies might deny a person insurance based on his or her chances of developing a disease!Explanation
The most likely concern that led to the passage of the Genetic Information Nondiscrimination Act is that insurance companies might deny a person insurance based on his or her chances of developing a disease. This act was passed to protect individuals from being discriminated against by insurance companies and employers based on the information obtained from genetic tests. By prohibiting such discrimination, the act ensures that individuals are not unfairly denied insurance coverage or charged higher rates due to their genetic predispositions.Rate this question:
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- 13.
How do alleles that display codominance differ from alleles that display simple dominance?
- A.
If two alleles are codominant then both alleles will be observed in heterozygotes!
- B.
If two alleles are codominant then the heterozygous phenotype will be somewhere between the homozygous phenotypes!
- C.
If two alleles display simple dominance then only the recessive allele will be observed in heterozygotes!
- D.
If two alleles display simple dominance then neither allele will be observed in heterozygotes!
Correct Answer
A. If two alleles are codominant then both alleles will be observed in heterozygotes!Explanation
If two alleles are codominant, it means that both alleles are expressed and observed in heterozygotes. This means that neither allele is dominant over the other, and both contribute to the phenotype. In contrast, if two alleles display simple dominance, only the dominant allele will be observed in heterozygotes, while the recessive allele will be masked. Therefore, the correct answer is that if two alleles are codominant, both alleles will be observed in heterozygotes.Rate this question:
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- 14.
Crossing dissimilar individuals to bring together their best characteristics is called
- A.
Domestication
- B.
Inbreeding
- C.
Hybridization
- D.
Polyploidy
Correct Answer
C. HybridizationExplanation
Hybridization refers to the process of crossing dissimilar individuals in order to bring together their best characteristics. This involves the breeding of two different species or varieties to create offspring with a combination of desirable traits from both parents. Through hybridization, breeders aim to improve the genetic diversity and overall quality of a population, resulting in hybrids that exhibit enhanced traits such as increased yield, disease resistance, or specific desirable traits.Rate this question:
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- 15.
Crossing individuals with similar characteristics so that those characteristics will appear in their offspring is called
- A.
Inbreeding
- B.
Hybridization
- C.
Recombination
- D.
Polyploidy
Correct Answer
A. InbreedingExplanation
Inbreeding is the correct answer because it refers to the process of crossing individuals with similar characteristics in order to increase the likelihood of those characteristics appearing in their offspring. This practice is often used in selective breeding to create purebred animals or plants with desired traits. Inbreeding can lead to a loss of genetic diversity and increased risk of genetic disorders, but it can also help to fix desired traits in a population.Rate this question:
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- 16.
Taking advantage of naturally occurring variations in organisms to pass wanted traits on to future generations is called
- A.
Selective Breeding
- B.
Inbreeding
- C.
Hybridization
- D.
Mutation
Correct Answer
A. Selective BreedingExplanation
Selective breeding is the process of intentionally choosing certain organisms with desired traits to reproduce, in order to pass those traits on to future generations. This method takes advantage of the natural variations that already exist within a species, and through careful selection and breeding, it can lead to the development of new varieties or breeds with specific characteristics. In contrast, inbreeding refers to the mating of closely related individuals, hybridization involves the crossing of two different species or varieties, and mutation refers to a sudden change in an organism's genetic material.Rate this question:
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- 17.
Organisms that contain genes from other organisms are called
- A.
Transgenic
- B.
Mutagenic
- C.
Donors
- D.
Clones
Correct Answer
A. TransgenicExplanation
Transgenic organisms are those that have genes from other organisms inserted into their own genetic material. This can be done through genetic engineering techniques, where specific genes are transferred from one organism to another. This process allows scientists to create organisms with desired traits or characteristics that may not naturally occur. Therefore, the correct answer is "Transgenic" because it accurately describes organisms that contain genes from other organisms.Rate this question:
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- 18.
When cell transformation is successful, the recombinant DNA
- A.
Undergoes mutation
- B.
Is treated with antibiotics
- C.
Becomes part of the transformed cell's genome
- D.
Becomes a nucleus
Correct Answer
C. Becomes part of the transformed cell's genomeExplanation
When cell transformation is successful, the recombinant DNA becomes part of the transformed cell's genome. This means that the introduced DNA is integrated into the genetic material of the cell and is replicated along with the rest of the cell's DNA during cell division. This allows the cell to express the genes carried by the recombinant DNA and produce the desired protein or trait.Rate this question:
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- 19.
Bacteria often contain small circular molecules of DNA known as
- A.
Clones
- B.
Chromosomes
- C.
Plasmids
- D.
Hybrids
Correct Answer
C. PlasmidsExplanation
Bacteria often contain small circular molecules of DNA known as plasmids. Plasmids are separate from the bacterial chromosome and can replicate independently. They can carry additional genetic information such as antibiotic resistance genes and can be transferred between bacteria through a process called conjugation. Plasmids play a significant role in genetic engineering and are commonly used as vectors to introduce foreign DNA into bacteria for various research and biotechnological applications.Rate this question:
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- 20.
A member of a population of genetically identical cells produced from a single cell is a
- A.
Clone
- B.
Plasmid
- C.
Mutant
- D.
Sequence
Correct Answer
A. CloneExplanation
A member of a population of genetically identical cells produced from a single cell is referred to as a clone. This means that all the cells in the population have the exact same genetic information as the original cell they were produced from. Cloning can occur naturally through asexual reproduction or can be artificially induced in a laboratory setting. This process is commonly used in scientific research and biotechnology to create identical copies of cells or organisms for various purposes.Rate this question:
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- 21.
Which of the following characteristics is often genetically engineered into crop plants?
- A.
Improved Flavor
- B.
Resistance to Herbicides
- C.
Shorter Ripening Times
- D.
Thicker Stems
Correct Answer
A. Improved FlavorExplanation
Genetically engineering improved flavor into crop plants involves manipulating the plant's genetic material to enhance its taste profile. This can be achieved by modifying genes responsible for producing certain compounds that contribute to flavor. By doing so, scientists can create crops with more desirable and appealing flavors, ultimately enhancing the eating experience for consumers. This genetic modification technique allows for the development of crops with improved flavor characteristics that may not be naturally present in traditional varieties.Rate this question:
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- 22.
A substance that has been genetically engineered into transgenic rice has the potential to treat
- A.
Cancer
- B.
High Blood Pressure
- C.
Vitamin A Deficiency
- D.
Malaria
Correct Answer
C. Vitamin A DeficiencyExplanation
Transgenic rice refers to rice that has been genetically modified to contain certain genes from other organisms. In this case, the substance that has been genetically engineered into transgenic rice has the potential to treat Vitamin A Deficiency. This means that the genetically modified rice may contain higher levels of Vitamin A, which can help address the deficiency of this essential nutrient in individuals who consume it.Rate this question:
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- 23.
Which of the following techniques would scientists most likely use to understand the activity levels of hundreds of genes at once?
- A.
A DNA microarray
- B.
PCR
- C.
Restriction Enzyme Analysis
- D.
DNA Sequencing
Correct Answer
A. A DNA microarrayExplanation
Scientists would most likely use a DNA microarray to understand the activity levels of hundreds of genes at once. A DNA microarray is a powerful tool that allows scientists to simultaneously analyze the expression levels of multiple genes. It works by immobilizing small DNA fragments representing different genes onto a solid surface, and then hybridizing them with labeled DNA or RNA samples. By measuring the intensity of the hybridization signals, scientists can determine the relative activity levels of the genes of interest. This technique enables high-throughput analysis and provides valuable insights into gene expression patterns.Rate this question:
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- 24.
The right to profit from a new genetic technology is protected by
- A.
Getting a copyright for the method!
- B.
Discovering a new gene!
- C.
Obtaining a patent!
- D.
Publishing its description in a journal!
Correct Answer
C. Obtaining a patent!Explanation
Obtaining a patent is the correct answer because it provides legal protection for a new genetic technology, allowing the inventor to have exclusive rights to profit from it. A patent grants the inventor the right to exclude others from making, using, or selling the patented invention for a certain period of time. This ensures that the inventor can recoup their investment in research and development and have a competitive advantage in the market. Copyright protects original works of authorship, such as written materials, but it does not provide the same level of protection for genetic technologies.Rate this question:
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- 25.
DNA fingerprinting is a technology that is used for many different purposes. The diagram below is an illustration of what DNA fingerprinting data may look like! Police departments and other agencies are often tasked with investigating crimes. Which of the following describes a solution to a problem investigators face that DNA fingerprinting can help solve?
- A.
DNA fingerprinting can be used to treat criminals that have a genetic disease or disorder!
- B.
DNA fingerprinting can be used to identify persons that were wrongly convicted of a crime!
- C.
DNA fingerprinting can be used to identify which genes are active in persons that commit crimes!
- D.
DNA fingerprinting can allow persons that commit crimes to be used as animal models in medical research studies!
Correct Answer
B. DNA fingerprinting can be used to identify persons that were wrongly convicted of a crime!Explanation
DNA fingerprinting can help solve the problem of wrongly convicted individuals by accurately identifying and matching DNA samples found at a crime scene to the actual perpetrator. This can provide crucial evidence to exonerate innocent individuals who may have been falsely accused or convicted of a crime. By comparing the DNA profiles of the suspect and the crime scene evidence, DNA fingerprinting can help ensure that the correct person is held accountable for the crime, leading to a more just and fair criminal justice system.Rate this question:
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- 26.
What do the dark bands in each sample represent?
- A.
Chromosomes
- B.
Active DNA Fragments
- C.
Clones
- D.
DNA fragments of different lengths
Correct Answer
D. DNA fragments of different lengthsExplanation
The dark bands in each sample represent DNA fragments of different lengths. Dark bands are observed when DNA fragments are separated based on their size using a technique called gel electrophoresis. In this technique, DNA samples are loaded onto a gel and an electric current is applied. Smaller DNA fragments move faster through the gel, while larger fragments move slower. As a result, different-sized DNA fragments appear as distinct bands, with the darkest bands representing the fragments of the greatest length.Rate this question:
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- 27.
A scientist is treating rice plants with a chemical that causes mutations. What is the possible benefit of this treatment?
- A.
Clones
- B.
Transgenic Plants
- C.
Increased Genetic Variation
- D.
Increased Hybridization
Correct Answer
C. Increased Genetic VariationExplanation
Treating rice plants with a chemical that causes mutations can lead to increased genetic variation. This is beneficial because it can result in the development of new traits and characteristics in the rice plants. Increased genetic variation can also enhance the plants' ability to adapt to changing environmental conditions, resist diseases, and improve overall crop productivity. This treatment can help in the breeding and selection of improved rice varieties with desirable traits, ultimately benefiting agriculture and food production.Rate this question:
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- 28.
One of the challenges facing the world today is supplying enough food for the human population. Farming with genetically modified plants is a possible solution to this challenge. What is a concern with using GM plants?
- A.
Farming with GM plants that are resistant to chemical herbicides may lead to overuse of weed-killing compounds!
- B.
Farming with GM plants requires less land and energy, which may lead to lower food costs and an economic crisis for farmers!
- C.
GM plants require more insecticide use, which may increase the chance of chemical residues in the food supply!
- D.
Scientific studies on GM plants are not available so the effects of GM plants are unknown!
Correct Answer
B. Farming with GM plants requires less land and energy, which may lead to lower food costs and an economic crisis for farmers! -
- 29.
A medical researcher hopes to cure a disease in mice by changing a gene. How can she change the sequence of a gene?
- A.
CRISPR
- B.
Cloning
- C.
Gel Electrophoresis
- D.
DNA Fingerprinting
Correct Answer
A. CRISPRExplanation
CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) can be used to change the sequence of a gene. CRISPR technology allows researchers to edit genes by removing, adding, or altering specific sections of DNA. It uses CRISPR-associated (Cas) proteins, such as Cas9, to target and cut specific DNA sequences. Once the DNA is cut, the cell's natural repair mechanisms can be employed to introduce desired changes to the gene sequence. This powerful tool has revolutionized genetic research and holds great potential for treating diseases in mice and potentially even in humans in the future.Rate this question:
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- 30.
Different forms of a gene are called
- A.
Hybrids
- B.
Dominant Factors
- C.
Alleles
- D.
Recessive Factors
Correct Answer
C. AllelesExplanation
Alleles are different forms of a gene that occupy the same position on a chromosome. They can vary in their DNA sequence and can result in different traits or characteristics. In genetics, an individual inherits two alleles for each gene, one from each parent. These alleles can be dominant or recessive, determining the expression of a particular trait. Therefore, the given answer "Alleles" accurately describes the different forms of a gene.Rate this question:
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- 31.
Organisms that have two identical alleles for a particular trait are said to be
- A.
Hybrid
- B.
Heterozygous
- C.
Homozygous
- D.
Dominant
Correct Answer
C. HomozygousExplanation
Organisms that have two identical alleles for a particular trait are said to be homozygous. This means that both alleles for the trait are the same, either both dominant or both recessive. Homozygous individuals will always express the trait associated with those alleles.Rate this question:
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- 32.
A Punnett square is used to determine the
- A.
Probable outcome of a cross!
- B.
Actual outcome of a cross!
- C.
Result of incomplete dominance!
- D.
Result of meiosis!
Correct Answer
A. Probable outcome of a cross!Explanation
A Punnett square is a tool used in genetics to predict the probable outcome of a cross between two individuals. By combining the genetic information of the parents, the Punnett square allows us to determine the possible combinations of alleles that their offspring may inherit. It provides a visual representation of the different genotypes and phenotypes that can result from the cross, helping us understand the likelihood of certain traits being passed on to the next generation.Rate this question:
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- 33.
The physical characteristics of an organism are called its
- A.
Genetics
- B.
Heredity
- C.
Phenotype
- D.
Genotype
Correct Answer
C. PhenotypeExplanation
The physical characteristics of an organism, such as its appearance, behavior, and other observable traits, are referred to as its phenotype. This includes features like eye color, height, and hair type. Phenotype is influenced by both genetic factors and environmental factors, as it is the result of the interaction between an organism's genotype (its genetic makeup) and its environment.Rate this question:
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- 34.
What is the probability of flipping a coin twice and getting two heads?
- A.
1
- B.
1/2
- C.
1/4
- D.
3/4
Correct Answer
C. 1/4Explanation
The probability of flipping a coin and getting heads is 1/2. Since the coin is flipped twice, the probability of getting heads on both flips is calculated by multiplying the probability of getting heads on the first flip (1/2) with the probability of getting heads on the second flip (also 1/2). Therefore, the probability of flipping a coin twice and getting two heads is 1/4.Rate this question:
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- 35.
A situation in which a gene has more than two alleles is known as
- A.
Complete Dominance
- B.
Codominance
- C.
Polygenic Dominance
- D.
Multiple Alleles
Correct Answer
D. Multiple AllelesExplanation
Multiple alleles refer to a situation where a gene has more than two alternative forms or variations. This means that there are more than two options for the expression of a particular trait. Each individual can have only two alleles, but within a population, there can be multiple variations of the gene. This can lead to a wide range of phenotypic expressions and genetic diversity within a population.Rate this question:
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- 36.
A pink-flowered Mirabilis plant (Rr) is crossed with a white-flowered Mirabilis (rr). What is the chance that a seed from this cross will produce a red-flowered plant (RR)?
- A.
0
- B.
1/4
- C.
1/2
- D.
1
Correct Answer
A. 0Explanation
When a pink-flowered Mirabilis plant (Rr) is crossed with a white-flowered Mirabilis (rr), the resulting offspring will have a genotype of Rr. In order for a seed to produce a red-flowered plant (RR), it would require both alleles to be dominant. However, since the pink-flowered plant only carries one dominant allele (R), there is no chance for the seed to produce a red-flowered plant. Therefore, the chance is 0.Rate this question:
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- 37.
The illustration below represents which stage of meiosis?
- A.
Prophase l
- B.
Anaphase ll
- C.
Telophase l
- D.
Metaphase l
Correct Answer
D. Metaphase lExplanation
The illustration represents Metaphase l of meiosis because it shows the chromosomes aligning at the equator of the cell. In this stage, the homologous chromosomes pair up and line up in the middle of the cell, ready for separation in the next stage. Anaphase ll is incorrect because it represents the separation of sister chromatids, which does not occur in Metaphase l. Prophase l and Telophase l are also incorrect because they represent different stages of meiosis.Rate this question:
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- 38.
Unlike mitosis, meiosis in male mammals results in the formation of
- A.
One haploid gamete!
- B.
Three diploid gametes!
- C.
Four diploid gametes!
- D.
Four haploid gametes!
Correct Answer
D. Four haploid gametes!Explanation
During meiosis in male mammals, the process starts with one diploid cell and ends with the formation of four haploid gametes. This is achieved through two rounds of cell division, resulting in the separation of homologous chromosomes and sister chromatids. Each of the resulting gametes contains half the number of chromosomes as the original cell, allowing for genetic diversity during sexual reproduction. Therefore, the correct answer is four haploid gametes.Rate this question:
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- 39.
A gene map shows
- A.
The number of possible alleles for a gene!
- B.
The relative locations of genes on a chromosome!
- C.
Where chromosomes are in a cell!
- D.
How crossing-over occurs. Suppose that an organism has the diploid number 2N = 8!
Correct Answer
B. The relative locations of genes on a chromosome!Explanation
A gene map shows the relative locations of genes on a chromosome. This means that it provides information about the order and distance between genes on a chromosome. By studying gene maps, scientists can understand how genes are arranged and organized on chromosomes, which can help in determining inheritance patterns and identifying the location of specific genes associated with certain traits or diseases.Rate this question:
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- 40.
Gregor Mendel crossed true-breeding plants with green pea pods with true-breeding plants with yellow pea pods. The resulting F1 generation all had green pea pods. What did he observe in the F2 generation?
- A.
Mendel observed green and yellow pea pods in a 3:1 ratio because the F1 generation was heterozygous!
- B.
Mendel observed green and yellow pea pods in a 4:1 ratio because the allele for green pea pods is dominant!
- C.
Mendel observed green and yellow pea pods in a 1:1 ratio because the F2 generation had the same characteristics as the parent generation!
- D.
Mendel observed only green pea pods because both parents had green pea pods!
Correct Answer
A. Mendel observed green and yellow pea pods in a 3:1 ratio because the F1 generation was heterozygous!Explanation
Mendel observed green and yellow pea pods in a 3:1 ratio because the F1 generation was heterozygous. This means that the F1 generation inherited one allele for green pea pods from one parent and one allele for yellow pea pods from the other parent. Since the allele for green pea pods is dominant, the plants in the F1 generation displayed the phenotype of green pea pods. However, in the F2 generation, the alleles for green and yellow pea pods segregated and recombined randomly during gamete formation, resulting in a 3:1 ratio of green to yellow pea pods.Rate this question:
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- 41.
Mitosis and meiosis are two different types of cell division. The model below illustrates anaphase of mitosis and anaphase I of meiosis! Which of the following is a difference between mitosis and meiosis that is supported by the model?
- A.
In anaphase of mitosis, sister chromatids separate. In anaphase I of meiosis, homologous chromosomes separate!
- B.
Anaphase of mitosis leads to four haploid cells. Anaphase I of meiosis leads to two diploid cells!
- C.
Crossing-over occurs after anaphase of mitosis, while crossing-over occurs before anaphase I of meiosis!
- D.
Chromosomes are not replicated before a cell enters anaphase of mitosis. Chromosomes have replicated before a cell enters anaphase I of meiosis!
Correct Answer
A. In anaphase of mitosis, sister chromatids separate. In anaphase I of meiosis, homologous chromosomes separate!Explanation
The correct answer is "In anaphase of mitosis, sister chromatids separate. In anaphase I of meiosis, homologous chromosomes separate!" This is supported by the model because it clearly shows that in mitosis, the sister chromatids (identical copies of each chromosome) separate and move to opposite poles of the cell, while in meiosis, the homologous chromosomes (pairs of chromosomes with similar genetic information) separate and move to opposite poles. This is a key difference between mitosis and meiosis and is clearly depicted in the model.Rate this question:
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- 42.
A biologist pollinates a true-breeding yellow flower with pollen from a true-breeding red flower of the same species. All of the F1 offspring are yellow. What question can be answered with the F2 cross?
- A.
Are yellow flowers maternally inherited?
- B.
Are yellow flowers recessive and red flowers dominant?
- C.
Are red and yellow flowers codominant?
- D.
Is flower color polygenic?
Correct Answer
D. Is flower color polygenic?Explanation
The F2 cross can answer the question of whether flower color is polygenic. By crossing the F1 offspring, which are all yellow, with each other, the biologist can observe the phenotypic ratios of the F2 generation. If the flower color is determined by multiple genes, then a range of colors may be observed in the F2 generation, indicating polygenic inheritance. If only yellow flowers are observed in the F2 generation, it would suggest that flower color is determined by a single gene, ruling out polygenic inheritance.Rate this question:
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- 43.
The gene map below shows some of the genes on chromosome 2 of the fruit fly Drosophila melanogaster! Which pair of traits is most likely to be inherited together?
- A.
Purple eye and brown eye because they are both eye traits!
- B.
Aristaless and speck body because they have the greatest chance of crossing-over!
- C.
Curved wing and arc (bent wings) because they have the least chance of crossing-over!
- D.
Black body and light eye because they are closest together on chromosome 2!
Correct Answer
B. Aristaless and speck body because they have the greatest chance of crossing-over!Explanation
The correct answer is Aristaless and speck body because they have the greatest chance of crossing-over. Crossing-over occurs during meiosis when genetic material is exchanged between homologous chromosomes. The closer two genes are on a chromosome, the less likely they are to undergo crossing-over and be inherited separately. Therefore, genes that are farther apart on a chromosome have a greater chance of crossing-over and being inherited together. In this case, Aristaless and speck body are the farthest apart on the gene map, indicating a higher likelihood of being inherited together.Rate this question:
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- 44.
The process by which one type of bacteria is changed into another type is called
- A.
Transcription
- B.
Transformation
- C.
Duplication
- D.
Replication
Correct Answer
B. TransformationExplanation
Transformation is the correct answer because it refers to the process by which one type of bacteria takes up and incorporates genetic material from another bacterium, resulting in a change in its genetic makeup and characteristics. This process can occur naturally or be induced in the laboratory, and it is an important mechanism for bacterial evolution and the spread of antibiotic resistance genes. Transcription, duplication, and replication are not accurate terms to describe this specific process of bacterial genetic change.Rate this question:
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- 45.
Bacteriophages are
- A.
A form of bacteria
- B.
Enzymes
- C.
Coils of DNA
- D.
Viruses
Correct Answer
D. VirusesExplanation
Bacteriophages are viruses that specifically infect bacteria. They are not a form of bacteria, enzymes, or coils of DNA. Bacteriophages have a protein coat that encapsulates their genetic material, which can be either DNA or RNA. They attach to the surface of bacterial cells and inject their genetic material into the host, taking over the bacterial machinery to replicate themselves. Therefore, the correct answer is viruses.Rate this question:
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- 46.
Which of the following researchers used radioactive markers in experiments to show that DNA was the genetic material in cells?
- A.
Frederick Griffith
- B.
Oswald Avery
- C.
Alfred Hershey and Martha Chase
- D.
James Watson and Francis Crick
Correct Answer
C. Alfred Hershey and Martha ChaseExplanation
Alfred Hershey and Martha Chase used radioactive markers in their experiments to demonstrate that DNA was the genetic material in cells. They conducted an experiment with bacteriophages, viruses that infect bacteria. They labeled the DNA of the bacteriophage with radioactive phosphorus and the protein coat with radioactive sulfur. Their results showed that only the DNA was transferred into the bacterial cells, confirming that DNA was indeed the genetic material responsible for heredity. This experiment provided crucial evidence supporting the understanding of DNA as the carrier of genetic information.Rate this question:
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- 47.
Before DNA could definitively be shown to be the genetic material in cells, scientists had to show that it could
- A.
Tolerate high temperatures
- B.
Carry and make copies of information
- C.
Be modified in response to environmental conditions
- D.
Be broken down into small subunits
Correct Answer
B. Carry and make copies of informationExplanation
To definitively establish DNA as the genetic material in cells, scientists needed to demonstrate that it could carry and replicate genetic information. This means that DNA should be able to store the instructions necessary for the development and functioning of an organism, as well as be capable of accurately duplicating itself during cell division. This ability of DNA to carry and make copies of information is crucial for the transmission of genetic traits from one generation to the next, and it was this characteristic that ultimately confirmed DNA as the genetic material.Rate this question:
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- 48.
A nucleotide does NOT contain
- A.
A 5-carbon sugar
- B.
An amino acid
- C.
A nitrogen base
- D.
A phosphate group
Correct Answer
B. An amino acidExplanation
A nucleotide is composed of a 5-carbon sugar, a nitrogen base, and a phosphate group. However, it does not contain an amino acid. Amino acids are the building blocks of proteins and are not typically found in nucleotides. Nucleotides, on the other hand, are the building blocks of nucleic acids such as DNA and RNA.Rate this question:
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- 49.
According to Chargaff's rule of base pairing, which of the following is true about DNA?
- A.
[A] = [T], and [C] = [G]
- B.
[A] = [C], and [T] = [G]
- C.
[A] = [G], and [T] = [C]
- D.
[A] = [T] = [C] = [G]
Correct Answer
A. [A] = [T], and [C] = [G]Explanation
Chargaff's rule of base pairing states that in DNA, the amount of adenine (A) is equal to the amount of thymine (T), and the amount of cytosine (C) is equal to the amount of guanine (G). This means that the ratio of A to T and the ratio of C to G are always 1:1. Therefore, the correct answer is [A] = [T], and [C] = [G].Rate this question:
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- 50.
The bonds that hold the two strands of DNA together come from
- A.
The attraction of phosphate groups for each other
- B.
Strong bonds between nitrogenous bases and deoxyribose
- C.
Weak hydrogen bonds between the nitrogenous bases
- D.
Carbon-to-carbon bonds in the sugar portion of the nucleotides
Correct Answer
C. Weak hydrogen bonds between the nitrogenous basesExplanation
The correct answer is weak hydrogen bonds between the nitrogenous bases. The two strands of DNA are held together by hydrogen bonds formed between the nitrogenous bases. These bases, adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C), through hydrogen bonding. These hydrogen bonds are relatively weak compared to covalent bonds, allowing the DNA strands to easily separate during replication and transcription processes.Rate this question:
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