Question 1

Jason was born with _____. The doctor tells his parents that compared to his peers, he will have a round face, flattened skull, an extra fold of skin over his eyelids, a thickened tongue, short limbs, and some intellectual difficulties.
A) fragile X syndrome
B) Klinefelter disease
C) Down syndrome
D) Tay-Sachs disease

Accepted Answer

Jason's symptoms are characteristic of Down syndrome, which is caused by an extra copy of chromosome 21 and leads to the physical and intellectual traits described.

Question 2

Which of the following is TRUE of Down syndrome?
A) It primarily occurs in African-American children.
B) It occurs when genetic imprinting goes awry.
C) Its symptoms include retardation of motor and mental abilities.
D) It is caused by the presence of an extra copy of chromosome Y.

Accepted Answer

Down syndrome is characterized by a range of physical and developmental symptoms, including delays in motor and mental abilities, due to the presence of an extra copy of chromosome 21, not chromosome Y.

Question 3

_____ genes are those that make the individual more vulnerable to specific diseases or acceleration of aging, whereas ____genes_make the individual less vulnerable to certain diseases and more likely to live to an older age.
A) Susceptibility; longevity
B) Longevity; mutated
C) Vulnerability; susceptibility
D) Mutated; good

Accepted Answer

Susceptibility genes increase the risk of diseases or aging, while longevity genes are associated with reduced disease risk and increased lifespan.

Question 4

Emma and Anna are identical twins who were adopted by different families a few weeks after birth. Although genetically identical, they grew up with different physical and psychological characteristics. For example, though both inherited a tendency to grow large, Anna was slim and athletic due to the active lifestyle practiced in her adoptive family. This variability can be explained by how:
A) each zygote is unique.
B) longevity genes can make an individual less vulnerable to certain diseases.
C) for each genotype, a range of phenotypes can be expressed.
D) mutated genes can be a source of genetic variability.

Accepted Answer

This variability can be explained by how, for each genotype, a range of phenotypes can be expressed. While Emma and Anna share the same genotype as identical twins, their different lifestyles and environments led to different phenotypic expressions.

Question 5

Erin is 90 years old. She has relatively good health and is fully mobile. Most of Erin's blood relatives lived to a much later age than most of their same-age friends. Which of the following genes might be responsible for this?
A) Susceptibility genes
B) Longevity genes
C) Vulnerability genes
D) Mutated genes

Accepted Answer

Longevity genes are associated with a longer lifespan and may contribute to Erin's family members living to an older age compared to their peers.

Question 6

Who is MOST likely to develop an X-linked disease?
A) Males
B) Females
C) Children of either gender
D) People with blonde hair

Accepted Answer

Males are most likely to develop X-linked diseases because they have only one X chromosome. If that X chromosome carries a recessive disease allele, they will express the disease, whereas females have two X chromosomes and can be carriers without expressing the disease.

Question 7

According to your text, gene-gene interactions have been documented in all of the following EXCEPT:
A) alcoholism.
B) asthma.
C) arthritis.
D) anxiety.

Accepted Answer

Gene-gene interactions have been documented in alcoholism, asthma, and arthritis, but not in anxiety according to the provided text.

Question 8

A recessive gene exerts its influence only if:
A) both genes in a pair are recessive.
B) it is the stronger gene.
C) the environment is right.
D) the dominant gene is also present in the pair.

Accepted Answer

A recessive gene is only expressed when both genes in a pair are recessive. If one dominant gene is present, it will override the recessive gene and be expressed instead. The presence of a dominant gene does not affect the expression of a recessive gene. The environment does not directly affect gene expression, although environmental factors can impact traits that are influenced by genes.

Question 9

In human beings, by the end of meiosis, each egg or sperm has _____ chromosomes.
A) 46 paired
B) 23 unpaired
C) 23 paired
D) 46 unpaired

Accepted Answer

Meiosis results in the formation of haploid cells, meaning each cell only contains half the number of chromosomes as the original cell. In humans, the original cell (a diploid cell) contains 46 chromosomes (23 pairs). By the end of meiosis, each egg or sperm has only 23 unpaired chromosomes, allowing for the proper number of chromosomes (46) to be present after fertilization.

Question 10

During _____, a cell of the testes in men or ovaries in women duplicates its chromosomes and then divides twice, thus forming four cells, each of which has only half the genetic material of the parent cell.
A) meiosis
B) mitosis
C) osmosis
D) fertilization

Accepted Answer

Meiosis is the process of division in gametes (sex cells) where a cell duplicates its chromosomes and undergoes two rounds of division resulting in four daughter cells, each with half the genetic material of the parent cell. This is necessary for sexual reproduction to ensure that offspring receive genetic diversity. Mitosis is the process of cell division that occurs in somatic cells (non-sex cells) for growth, repair, and maintenance, and produces two daughter cells with identical genetic material to the parent cell. Osmosis is the passive movement of water molecules through a selectively permeable membrane from an area of high water concentration to an area of low water concentration, while fertilization is the fusion of gametes to form a zygote with a full set of genetic material.

Question 11

In some cases, one gene of a pair always exerts its effects, overriding the potential influence of the other gene. This is the _____ principle.
A) sex-linked genes
B) dominant-recessive genes
C) genetic imprinting
D) polygenic inheritance

Accepted Answer

The dominant-recessive genes principle refers to situations where one gene in the pair (the dominant gene) has a greater impact on the phenotype than the other gene (the recessive gene). This means that even if an individual inherits one dominant gene and one recessive gene, the dominant gene will be expressed in the phenotype.

Question 12

Joseph was born with the potential to be quite tall; however, during his childhood his family struggled and he didn't have a nutritious diet. The result is that Joseph is not as tall as his parents. Another way of describing Joseph's situation is that his ______ was(were) not expressed in his _____.
A) phenotype; genotype
B) susceptibility genes; longevity genes
C) genotype; phenotype
D) longevity genes; susceptibility genes

Accepted Answer

Joseph's genetic potential for height (genotype) was not fully realized in his physical height (phenotype) due to environmental factors like poor nutrition.

Question 13

During fertilization, an egg and a sperm fuse to create a single cell called a:
A) blastocyst.
B) fetus.
C) gamete.
D) zygote.

Accepted Answer

During fertilization, the sperm's genetic material combines with the egg's genetic material to create a single-celled organism called a zygote. The zygote contains all the necessary genetic information to develop into a complete organism.

Question 14

Carrie's parents both have brown hair. However, Carrie gets genes for blonde hair from both parents, and as a result she has blonde hair. This indicates that the gene for blonde hair is a:
A) recessive gene.
B) dominant gene.
C) susceptibility gene.
D) longevity gene.

Accepted Answer

Blonde hair is a recessive trait, meaning both parents must carry the recessive gene for blonde hair for their child to express it.

Question 15

_____ is caused by the presence of an extra copy of chromosome 21.
A) Down syndrome
B) Hemophilia
C) Huntington's disease
D) Sickle-cell anemia

Accepted Answer

Down syndrome is caused by trisomy 21, which means there is an extra copy of chromosome 21.

Question 16

_____ genes are those that make the individual less vulnerable to certain diseases and more likely to live to an older age.
A) Susceptibility
B) Longevity
C) Vulnerability
D) Mutated

Accepted Answer

Longevity genes are associated with increased lifespan and reduced risk of age-related diseases, contributing to a longer and healthier life.

Question 17

Clark's genotype contains a dominant gene for brown eye color and a recessive gene for blue eye color. According to the dominant-recessive gene principle, which of the following phenotypes is most likely to be observed in Clark?
A) Black eyes
B) Blue eyes
C) Grey eyes
D) Brown eyes

Accepted Answer

According to the dominant-recessive gene principle, the dominant gene (brown eye color) will mask the expression of the recessive gene (blue eye color), resulting in the phenotype of brown eyes.

Question 18

Mary's mother has blonde hair and her father has brown hair. Mary has a gene for brown hair and a gene for blonde hair. She has brown hair. This indicates that the gene for brown hair is a:
A) dominant gene.
B) recessive gene.
C) susceptible gene.
D) longevity gene.

Accepted Answer

Since Mary has brown hair, which is the dominant trait, it means that she only needs one copy of the brown hair gene to express that trait. This indicates that the gene for brown hair is a dominant gene.

Question 19

_____ is the way an individual's genotype is expressed in observable and measurable characteristics.
A) RNA
B) DNA
C) Phenotype
D) Stereotype

Accepted Answer

Phenotype is the term used to describe the way an individual's genetic makeup (genotype) is expressed in observable and measurable characteristics, such as physical traits or disease susceptibility. RNA and DNA are both involved in carrying and expressing genetic information, but they are not directly related to the concept of phenotype. Stereotype refers to a fixed or oversimplified idea about a group of people, and is unrelated to genetics.

Question 20

Marly describes her friend, Gina, as having blonde hair, green eyes, and fair skin with freckles. Marly has described Gina's:
A) genotype.
B) genetic imprint.
C) phenotype.
D) X-linked inheritance.

Accepted Answer

Marly is describing Gina's observable physical traits or phenotype. The other options do not fit the description of the information provided.

Quiz 2: Biological Beginnings

Jason was born with _____. The doctor tells his parents that compared to his peers, he will have a round face, flattened skull, an extra fold of skin over his eyelids, a thickened tongue, short limbs, and some intellectual difficulties.

Which of the following is TRUE of Down syndrome?

_ genes are those that make the individual more vulnerable to specific diseases or acceleration of aging, whereas genes_make the individual less vulnerable to certain diseases and more likely to live to an older age.

Erin is 90 years old. She has relatively good health and is fully mobile. Most of Erin's blood relatives lived to a much later age than most of their same-age friends. Which of the following genes might be responsible for this?

Who is MOST likely to develop an X-linked disease?

According to your text, gene-gene interactions have been documented in all of the following EXCEPT:

A recessive gene exerts its influence only if:

In human beings, by the end of meiosis, each egg or sperm has _____ chromosomes.

During _____, a cell of the testes in men or ovaries in women duplicates its chromosomes and then divides twice, thus forming four cells, each of which has only half the genetic material of the parent cell.

In some cases, one gene of a pair always exerts its effects, overriding the potential influence of the other gene. This is the _____ principle.

Joseph was born with the potential to be quite tall; however, during his childhood his family struggled and he didn't have a nutritious diet. The result is that Joseph is not as tall as his parents. Another way of describing Joseph's situation is that his __ was(were) not expressed in his _.

During fertilization, an egg and a sperm fuse to create a single cell called a:

Carrie's parents both have brown hair. However, Carrie gets genes for blonde hair from both parents, and as a result she has blonde hair. This indicates that the gene for blonde hair is a:

_____ is caused by the presence of an extra copy of chromosome 21.

_____ genes are those that make the individual less vulnerable to certain diseases and more likely to live to an older age.

Clark's genotype contains a dominant gene for brown eye color and a recessive gene for blue eye color. According to the dominant-recessive gene principle, which of the following phenotypes is most likely to be observed in Clark?

Mary's mother has blonde hair and her father has brown hair. Mary has a gene for brown hair and a gene for blonde hair. She has brown hair. This indicates that the gene for brown hair is a:

_____ is the way an individual's genotype is expressed in observable and measurable characteristics.

Marly describes her friend, Gina, as having blonde hair, green eyes, and fair skin with freckles. Marly has described Gina's: