1.
Each molecule of DNA is called a:
Correct Answer
D. Chromosome
Explanation
Each molecule of DNA is called a chromosome. A chromosome is a long, thread-like structure made up of DNA and proteins, which carries the genetic information of an organism. DNA molecules are packaged into chromosomes in the nucleus of a cell. Chromosomes are responsible for passing on traits from one generation to the next during cell division and reproduction.
2.
The chemicals that send instructions to cells are:
Correct Answer
B. A, T, C, and G
Explanation
The chemicals A, T, C, and G are nucleotides that make up DNA and RNA molecules. These nucleotides carry genetic information and act as instructions for cells. A represents adenine, T represents thymine, C represents cytosine, and G represents guanine. These nucleotides form base pairs and encode the genetic code, which is then translated into proteins and other cellular components. Therefore, A, T, C, and G are the chemicals that send instructions to cells.
3.
A person's
genetic inherited potential is called the _______, while a person's
actual appearance and behavior is called the________.
Correct Answer
A. Genotype; pHenotype
Explanation
The term "genotype" refers to a person's genetic inherited potential, which includes the combination of genes they have inherited from their parents. On the other hand, "phenotype" refers to a person's actual appearance and behavior, which is determined by the interaction between their genes and the environment. Therefore, the correct answer is genotype; phenotype.
4.
Approximately
the same number of males and females are born every year. If scientists
found a way to cure stressful pregnancies, how would this effect the
number of males born every year:
Correct Answer
A. The number of males born would increase
Explanation
If scientists found a way to cure stressful pregnancies, it is likely that the number of males born every year would increase. Stress during pregnancy has been associated with various negative effects on fetal development, including a higher likelihood of premature birth and low birth weight. By reducing stress during pregnancy, it is possible that more pregnancies would reach full term and result in the birth of healthy babies, including more males. However, without further information, it is not possible to determine the exact extent of the increase or if there would be any other factors that could influence the number of males born.
5.
Differentiation occurs when:
Correct Answer
D. Cells begin to specialize
Explanation
Differentiation occurs when cells begin to specialize. This means that cells in a developing organism start to take on specific functions and characteristics. During this process, certain genes are activated or deactivated, leading to the development of different cell types with distinct structures and functions. This specialization is crucial for the proper functioning of tissues and organs in multicellular organisms. The other options mentioned in the question, such as the sperm and ovum meeting or the zygote reaching the 4-cell stage, are events that occur earlier in the process of embryonic development and do not directly relate to cellular specialization.
6.
The genetic explanation for the differences between chimps and humans concerns differences in:
Correct Answer
A. Regulator genes
Explanation
The genetic explanation for the differences between chimps and humans concerns differences in regulator genes. Regulator genes are responsible for controlling the expression of other genes and play a crucial role in determining the development and functioning of an organism. Differences in regulator genes can lead to variations in gene expression, which can result in distinct traits and characteristics between species. Therefore, the genetic dissimilarities between chimps and humans can be attributed to variances in their regulator genes.
7.
Additive genes contribute to the:
Correct Answer
C. pHenotype
Explanation
Additive genes contribute to the phenotype. Phenotype refers to the observable characteristics or traits of an organism, such as its physical appearance or behavior. Additive genes are those that have a cumulative effect on the phenotype, meaning that each gene contributes a small amount to the overall phenotype. This is in contrast to dominant-recessive patterns, which are determined by the interaction between different alleles of a single gene. Genotype refers to the genetic makeup of an organism, while gametes are the reproductive cells involved in sexual reproduction.
8.
What is the correct order of the processes that occur after a zygote is formed?
Correct Answer
C. 23 Pairs of chromosomes duplicate, divide several times, and then cells differentiate
Explanation
After a zygote is formed, the correct order of the processes that occur is that 23 pairs of chromosomes duplicate, divide several times, and then cells differentiate. This means that the chromosomes first duplicate to ensure that each new cell has the same genetic information. Then, the duplicated chromosomes divide several times to create multiple cells. Finally, these cells differentiate, meaning they specialize and take on specific functions within the organism.
9.
A slight variation of a particular gene is called an:
Correct Answer
B. Allele
Explanation
An allele is a term used to describe a slight variation of a particular gene. It refers to the different forms of a gene that can exist at a specific locus on a chromosome. Alleles are responsible for the variations in traits observed within a population.
10.
Most humans have ____ pair(s) of autosomes and ____ pair(s) of sex chromosome
Correct Answer
B. 22; 1
Explanation
Most humans have 22 pairs of autosomes and 1 pair of sex chromosomes. Autosomes are non-sex chromosomes, which means they do not determine the sex of an individual. Humans have 44 autosomes in total, arranged in 22 pairs. The sex chromosomes, on the other hand, determine the sex of an individual. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY). Therefore, the correct answer is 22; 1.
11.
In the United States, it is illegal to:
Correct Answer
A. Surgically insert two groups of cells that have been separated from an in vitro fertilized ovum
Explanation
The given answer states that it is illegal to surgically insert two groups of cells that have been separated from an in vitro fertilized ovum. This means that it is against the law to insert two separate groups of cells that have been taken from a fertilized egg through in vitro fertilization. This could refer to a procedure where the cells are separated and then inserted into different parts of the body or used for different purposes. The legality of this action suggests that there are specific regulations and ethical considerations surrounding the use and manipulation of in vitro fertilized cells.
12.
IVF zygotes have been surgically implanted into Norma's womb. What is the chance of one of them implanting and developing?
Correct Answer
C. A 30 percent chance of implanting and developing
Explanation
The correct answer is a 30 percent chance of implanting and developing. This suggests that there is a relatively low probability of the IVF zygotes successfully implanting and developing in Norma's womb.
13.
Which type of twin is created from two separate zygotes?
Correct Answer
A. Dizygotic
Explanation
Dizygotic twins, also known as fraternal twins, are created from two separate zygotes. This means that two eggs are fertilized by two separate sperm cells, resulting in two genetically distinct embryos. Dizygotic twins can be of the same or different sexes and may or may not resemble each other closely. In contrast, monozygotic twins, also known as identical twins, are created from a single zygote that splits into two embryos, resulting in twins who are genetically identical. Cloned twins, on the other hand, refer to a hypothetical scenario where twins are created through the process of cloning, which is not a natural occurrence in humans.
14.
A person whose genotype includes a gene that is not expressed in the phenotype is called:
Correct Answer
B. A carrier
Explanation
A carrier is a person who has a gene in their genotype but does not show or express it in their phenotype. This means that although they carry the gene, they do not exhibit any symptoms or characteristics associated with it. Carriers are often unaffected by the gene themselves but can pass it on to their offspring.
15.
Research reported in The Relationship Code found that:
Correct Answer
D. All of the answers are correct
Explanation
The research reported in The Relationship Code suggests that genes play a significant role in shaping every characteristic of a child. Additionally, the research helps to elucidate the complex interplay between nature and nurture in child development. Furthermore, the study shows that family structure and parental style can modify the influence of genetics on children. Therefore, all of the given answers are correct.
16.
Examples of the interaction of genotype and phenotype can be easily identified in:
Correct Answer
D. All of the above
Explanation
The interaction of genotype and phenotype refers to how an individual's genetic makeup (genotype) influences their observable traits and characteristics (phenotype). In the case of alcoholism, mental illnesses, and nearsightedness, there is evidence to suggest that both genetic factors and environmental factors play a role in the development of these conditions. Therefore, all of the mentioned examples demonstrate the interaction between genotype and phenotype.
17.
Dr. Chan
has diagnosed 8-year old Hsu with myopia. He recommends that Hsu
should spend more time playing outside in the sun. Why would Dr. Chan
make this recommendation?
Correct Answer
A. Dr. Chan recognizes the importance of the interaction of the environment on Hsu inherited visual genes.
Explanation
Dr. Chan believes that spending more time playing outside in the sun will have a positive impact on Hsu's myopia because he understands the significance of the environment in influencing the expression of visual genes that Hsu has inherited. He believes that the outdoor environment and exposure to sunlight can potentially slow down the progression of myopia in Hsu.
18.
Why is it important to be knowledgeable about chromosomal and genetic abnormalities?
Correct Answer
D. All of the above
Explanation
It is important to be knowledgeable about chromosomal and genetic abnormalities because they provide insight into the complexities of nature and nurture. Understanding these abnormalities helps reduce prejudices towards individuals with these conditions. Additionally, knowing the origins of these abnormalities can help limit their effects and provide opportunities for early intervention and treatment.
19.
Eric has been identified as having cells with 45 chromosomes and others with 46 chromosomes. This condition is called:
Correct Answer
A. Mosaic
Explanation
The condition described in the question, where Eric has cells with both 45 and 46 chromosomes, is called mosaic. Mosaic refers to a condition where an individual has two or more different populations of cells with different genetic makeup within their body. In this case, Eric has cells with both 45 and 46 chromosomes, indicating a mosaic pattern.
20.
Which of the following statements about individuals with Down syndrome is true?
Correct Answer
D. Their life expectancy is shorter than that of other adults
Explanation
Individuals with Down syndrome have a shorter life expectancy compared to other adults. Down syndrome is a genetic disorder caused by the presence of an extra copy of chromosome 21. This additional genetic material can lead to various physical and cognitive challenges. While medical advancements have improved the quality of life for individuals with Down syndrome, they still face a higher risk of health issues such as heart problems, respiratory infections, and early-onset Alzheimer's disease, which can contribute to a shorter lifespan.
21.
Each of the following results from an atypical number of chromosomes, except:
Correct Answer
A. Tourette syndrome
Explanation
Tourette syndrome is not caused by an atypical number of chromosomes. It is a neurological disorder characterized by repetitive, involuntary movements and vocalizations. The exact cause of Tourette syndrome is unknown, but it is believed to involve a combination of genetic and environmental factors. It is not associated with any specific chromosomal abnormality. On the other hand, Turner syndrome is caused by a missing or incomplete X chromosome, Down syndrome is caused by an extra copy of chromosome 21, and Klinefelter syndrome is caused by an extra X chromosome in males.
22.
Which genetic disorder is sex-linked, appears on the X chromosome, and may result in mental retardation?
Correct Answer
C. Fragile X syndrome
Explanation
Fragile X syndrome is a genetic disorder that is sex-linked, meaning it appears on the X chromosome. It is characterized by a mutation in the FMR1 gene, which can lead to intellectual disabilities and learning difficulties. Fragile X syndrome is more commonly seen in males, as they only have one X chromosome, while females have two. This disorder can result in mental retardation due to the impact on brain development and functioning.
23.
Carriers of the sickle-cell trait are:
Correct Answer
A. Less likely to die of malaria
Explanation
Carriers of the sickle-cell trait are less likely to die of malaria. This is because individuals who carry the sickle-cell trait have a genetic variation that causes their red blood cells to have a sickle shape. While this shape can cause health issues, it also makes it difficult for the malaria parasite to survive and reproduce within the red blood cells. Therefore, carriers of the sickle-cell trait have a natural protection against severe malaria, reducing their likelihood of dying from the disease.
24.
According
to the text, some historians believe that a disease was an underlying
cause of the Russian revolution of 1917. What was this disease?
Correct Answer
A. HemopHilia
Explanation
Some historians believe that hemophilia was an underlying cause of the Russian revolution of 1917. Hemophilia is a genetic disorder that affects the blood's ability to clot, leading to excessive bleeding even from minor injuries. This disease affected the Russian royal family, particularly Tsar Nicholas II's son Alexei, who suffered from hemophilia. The constant worry and stress over the health of the heir to the throne, along with the ineffective treatment methods available at the time, added to the already existing social and political tensions in Russia, contributing to the revolution.
25.
Why does genetic testing and counseling produce uncertainty?
Correct Answer
D. All of the above
Explanation
Genetic testing and counseling produce uncertainty because news of a harmful gene that can produce a possible disorder creates new uncertainties. Additionally, medical treatments have not yet been discovered for some disorders, adding to the uncertainty. Furthermore, the interaction of genes and the environment makes development over the life span unpredictable, further contributing to the overall uncertainty in genetic testing and counseling.