Question 1

Which of the following is not characteristic of 'X-linked inheritance'?
A)It is caused by genes on chromosome 23
B)Females are more severely affected
C)Affected males pass the gene to 100% of their daughters
D)There is no father-to-son transmission
E)Affected females can transmit the disorder to their sons

Accepted Answer

Females are typically carriers of X-linked disorders, but they are not usually more severely affected than males who have the disorder. In fact, because females have two X chromosomes and males have only one, females are often less severely affected because they may have a normal copy of the affected gene on their other X chromosome.

Question 2

What term is used to describe having two different alleles of a gene for a particular trait?
A)Homozygous
B)Phenotypic
C)Autosomal dominant
D)Heterozygous
E)Multifactorial

Accepted Answer

Heterozygous means having two different alleles of a gene for a particular trait. Homozygous would mean having two of the same alleles, and phenotypic and multifactorial refer to different concepts. Autosomal dominant refers to a pattern of inheritance for a particular trait, not the genetic makeup of an individual.

Question 3

Which of the following results in Down syndrome?
A)Monosomy 22
B)Trisomy 21
C)Trisomy 23
D)Trisomy 13
E)Trisomy 16

Accepted Answer

Down syndrome occurs due to the presence of an extra copy of chromosome 21, also known as trisomy 21. Monosomy 22 means the individual has only one copy of chromosome 22, which is not related to Down syndrome. Trisomy 23, Trisomy 13 and Trisomy 16 involve extra copies of chromosomes different from number 21 and are associated with different genetic disorders.

Question 4

In a case in which two individuals who are heterozygous carriers of an autosomal recessive condition have a child, what is the probability that the child is a carrier of a single copy of the mutation?
A)50%
B)25%
C)100%
D)0%
E)75%

Accepted Answer

When both parents are heterozygous carriers of an autosomal recessive condition, their genotypes can be represented as Aa (where A is the normal allele and a is the mutated allele). The possible genotypes for their offspring, based on simple Mendelian genetics, are AA, Aa, Aa, and aa. Thus, there is a 50% chance (2 out of 4 possibilities) that the child will inherit one copy of the mutated allele and one copy of the normal allele, making them a carrier (Aa).

Question 5

Which of the following would be considered a threshold trait associated with multifactorial inheritance?
A)Height
B)Intelligence
C)Blood pressure
D)Cleft palate
E)Weight

Accepted Answer

A threshold trait is a trait that only expresses when a certain level or threshold of a given factor is passed. Cleft palate is an example of a threshold trait because it only expresses when a certain threshold of genetic and/or environmental factors is exceeded. Height, intelligence, blood pressure, and weight are not considered threshold traits as they do not have a specific cutoff point for their expression.

Question 6

What is the recurrence risk for parents of a child with nonsyndromic cleft lip and/or palate with their next pregnancy?
A)3% to 5%
B)25% to 50%
C)30% to 45%
D)10% to 15%
E)5% to 10%

Accepted Answer

The recurrence risk for parents of a child with nonsyndromic cleft lip and/or palate with their next pregnancy is generally estimated to be between 3% to 5%. This risk can vary based on factors such as the number of affected family members and the presence of cleft lip and palate versus cleft lip alone or cleft palate alone.

Question 7

Which factors) produces) the greatest risk for cleft lip?
A)Carrying the rare polymorphism of the TGFA gene
B)Having a family history with two affected first-degree relatives with cleft lip
C)Heavy maternal smoking plus carrying the high-risk allele of TGF
D)Having a family history with one individual with cleft lip
E)Heavy maternal smoking

Accepted Answer

Having a family history with two affected first-degree relatives with cleft lip indicates a strong genetic predisposition, which is a significant risk factor for cleft lip.

Question 8

Which of the following describes traits that manifest only when mutations are present in both copies of a gene?
A)Dominant traits
B)Recessive traits
C)Heterogeneous traits
D)Homogenous traits
E)Autosomal dominant traits

Accepted Answer

Recessive traits manifest only when mutations are present in both copies of a gene. This means that an individual must inherit two copies of the mutated gene, one from each parent, to exhibit the trait.

Question 9

What is the possibility that their offspring will be carriers of the condition?
A)0%
B)25%
C)50%
D)75%
E)100%

Accepted Answer

If one parent has a recessive gene for a condition and the other parent does not have the gene, then the offspring will not have the condition but will be carriers with a 50% chance of inheriting the recessive gene from the carrier parent.

Question 10

Which of the following changes in genes does not result in craniofacial anomalies?
A)Deletion of one or more nucleotides
B)Changing the regulation of gene expression
C)Insertion of one or more nucleotides
D)Polymorphism
E)Change in the function of a protein

Accepted Answer

Polymorphism refers to variations in DNA sequence that are common in a population and are not associated with any disease or abnormal phenotype. Therefore, it is unlikely to result in craniofacial anomalies. The other options could potentially result in changes to the structure or function of proteins involved in craniofacial development, leading to anomalies.

Question 11

A woman and her husband are both heterozygous carriers of an autosomal recessive condition. What is the possibility that their offspring will have the condition?
A)0%
B)25%
C)50%
D)75%
E)100%

Accepted Answer

Since both parents are heterozygous carriers, they each have one copy of the mutated gene and one copy of the normal gene. During reproduction, there is a chance that each parent will pass on the mutated gene to their offspring. The Punnett square for a heterozygous cross shows that the probability of the offspring inheriting two copies of the mutated gene (and therefore having the condition) is 25%, while the probability of inheriting one mutated gene and one normal gene (and being a carrier like the parents) is 50%. The probability of inheriting two normal genes is also 25%, and this would mean that the offspring would not have the condition and would also not be a carrier.

Question 12

Which of the following is not a rule of inheritance that Mendel described?
A)All alleles are dominant
B)Variations of genes are referred to as alleles
C)We get one gene from each parent
D)Alleles segregate from each other at meiosis

Accepted Answer

This statement is not true. Mendel described that some alleles are dominant and others are recessive.

Question 13

Match between columns
                        Premises: When genes function differently, depending on whether they were inherited maternally or paternally
The phenomenon in which a single mutant gene can affect multiple, unrelated systems
Environmental factors known to increase risks for birth defects
Disorders resulting from an interaction of multiple genes with environmental influences
Occurs when a specific phenotype can be caused by mutations of different genes
A tendency to have more severe manifestations or an earlier age of onset in succeeding generations
The lack of a recognizable phenotype in an individual who carries a mutation that may cause an autosomal dominant trait or condition

Accepted Answer

The Answer of Anticipation and Pleiotropy and Premeditation and Heterogeneity is...

Question 14

Match between columns
                        Premises: When there is a single copy of the chromosome
Occurs with Down syndrome
A cause of velocardiofacial syndrome
When a part of a chromosome becomes separated and lost
Failure of a pair of chromosomes to separate during cell division
When the cells have different genetic content in a single individual
When a portion of the chromosome is turned 180º from its original location
When there is a transfer of genetic material between two or more chromosomes

Accepted Answer

The Answer of Duplications and Mosaicism and Nondisjunction and Inversions is...

Question 15

Match between columns
                        Premises: A visual profile of an individual's chromosomes
The separation of the cell cytoplasm to form two distinct cells
A schematic drawing of the banding pattern of a chromosome
A complete set of genetic instructions for a particular organism or species
A group of typical characteristics associated with a genetic condition
A pictorial representation of family members and their line of descent

Accepted Answer

The Answer of Phenotype and Karyotype and Cytokinesis and Pedigree is...

Question 16

Match between columns
                        Premises: A process where a complementary strand of DNA is created with a single strand
Variability in genes common in the general population
Change in the sequence of a molecule of DNA
The substance that carries hereditary information in bacteria
A single, linear double strand of DNA with associated proteins
Submicroscopic functional unit of heredity located in the nucleus of a cell created as a single complementary strand of a DNA template
The process of making two identical DNA molecules from one
Created as a single complementary strand of a DNA template

Accepted Answer

The Answer of Gene and Transcription and Replication and Mutation is...

Question 17

Match between columns
                        Premises: Sperm cells from the testes and ova cells from the ovaries
The 23rd pair of chromosomes, identified as X and Y because of their role in gender determination
Long arm on each side of a chromosome
Short arm on each side of a chromosome
Cells in the body with the exception of those for reproduction
Includes all chromosomes with the exception of the two sex chromosomes

Accepted Answer

The Answer of Autosomes and Somatic cells and Gametes and is...

Quiz 4: Genetics and Patterns of Inheritance

Which of the following is not characteristic of 'X-linked inheritance'?

What term is used to describe having two different alleles of a gene for a particular trait?

Which of the following results in Down syndrome?

In a case in which two individuals who are heterozygous carriers of an autosomal recessive condition have a child, what is the probability that the child is a carrier of a single copy of the mutation?

Which of the following would be considered a threshold trait associated with multifactorial inheritance?

What is the recurrence risk for parents of a child with nonsyndromic cleft lip and/or palate with their next pregnancy?

Which factors) produces) the greatest risk for cleft lip?

Which of the following describes traits that manifest only when mutations are present in both copies of a gene?

What is the possibility that their offspring will be carriers of the condition?

Which of the following changes in genes does not result in craniofacial anomalies?

A woman and her husband are both heterozygous carriers of an autosomal recessive condition. What is the possibility that their offspring will have the condition?

Which of the following is not a rule of inheritance that Mendel described?

Match the number of the answer with each item

Match the number of the answer with each item

Match the number of the answer with each item

Match the number of the answer with each item.

Match the number of the answer with each item.