Question 1

The research on the effects of abusive parenting on children with a particular genotype demonstrated that:

Accepted Answer

The research shows that specific genetic risk factors can make some individuals more susceptible than others to particular environmental events, such as abusive parenting. This suggests that genetics and environment both play a role in the development of outcomes related to abusive parenting, rather than child abuse being solely genetically inherited or determined by phenotype.

Question 2

Down syndrome originates from:

Accepted Answer

Down syndrome results from a chromosomal anomaly, specifically an extra copy of chromosome 21. This is also referred to as trisomy 21. It is not caused by polygenic inheritance, dominant-recessive patterns, or gene anomalies.

Question 3

All the outcomes that could theoretically result from a given genotype are referred to as the:

Accepted Answer

The norm of reaction refers to the range of phenotypes that can result from a single genotype under different environmental conditions.

Question 4

Many psychiatric and behavioural disorders are believed to involve:

Accepted Answer

The answer of Many psychiatric and behavioural disorders are believed...

Question 5

Disease W is a recessive gene disease. Individuals with _____ will suffer from disease W.

Accepted Answer

Disease W is a recessive gene disease, which means that an individual must have two copies of the disease gene to express the disease. Therefore, only individuals with two disease W genes (option B) will suffer from disease W. Individuals with one disease W gene and one healthy gene (option A), or with two healthy genes (option C) will not express the disease, while individuals with two disease W genes and one healthy gene (option D) will also not express the disease as the healthy gene will prevent it from being expressed.

Question 6

The manner in which individuals develop phenylketonuria is an example of:

Accepted Answer

Phenylketonuria is caused by a genetic mutation that affects the individual's ability to process phenylalanine, resulting in a buildup of toxic compounds in the body. However, the severity of the condition can be influenced by environmental factors such as the individual's diet. This is a clear example of genotype-environment interaction.

Question 7

Polygenic inheritance refers to:

Accepted Answer

Polygenic inheritance refers to the combined action of multiple genes in determining a single trait. This means that many genes are involved in determining the phenotype (observable physical or biochemical characteristics of an organism) of a particular trait, and the contribution of each gene may be relatively small. Examples include height, skin color, and intelligence, which are all influenced by multiple genes.

Question 8

Phenylketonuria originates from:

Accepted Answer

Phenylketonuria (PKU) is caused by a recessive allele on an autosomal chromosome, meaning it follows a dominant-recessive inheritance pattern. Individuals must inherit two copies of the faulty gene, one from each parent, to exhibit the disorder.

Question 9

Kody, a boy, and Shakira, a girl, are brother and sister. They both inherit the same recessive allele for trait T on their X chromosome from their mother. What is the relative likelihood of Kody and Shakira expressing trait T?

Accepted Answer

Kody has only one X chromosome (XY), so if he inherits a recessive allele for trait T from his mother, he will express it because he lacks a second X chromosome that could potentially carry a dominant allele to mask the recessive one. Shakira, on the other hand, has two X chromosomes (XX), so she would need to inherit the recessive allele for trait T from both parents to express the trait. Therefore, Kody is more likely to express trait T than Shakira.

Question 10

Identical twins Ilyse and Lauren both have a gene for trait H. The gene for trait H is expressed only when a child eats rice before the age of 2 years. Ilyse and Lauren are separated at birth, and Ilyse lives in Japan, where babies begin eating rice at an early age. Lauren lives in Canada, and she is not given rice before the age of 2 years. Ilyse develops trait H, whereas Lauren does not develop the trait. This is an example of:

Accepted Answer

This is an example of genotype-environment interaction where both twins have the same genotype but different environments lead to different expressions of the trait. The gene for trait H is expressed only when the child eats rice before the age of 2 years, thus the different environments lead to different expressions of the gene in the twins.

Question 11

Which property is a NOT mechanism for genetic inheritance of disease?

Accepted Answer

Hormonal abnormalities are not a mechanism for genetic inheritance of disease. Hormonal abnormalities can be caused by genetic mutations, but they are not a mode of inheritance themselves. Combined action of multiple genes, dominant-recessive patterns, and sex-linked inheritance are all mechanisms for genetic inheritance of disease.

Question 12

Which statement about traits that involve polygenic inheritance is TRUE?

Accepted Answer

Polygenic inheritance involves the interaction of multiple genes to determine a trait, and many common human disorders, such as heart disease and diabetes, are believed to result from such interactions in combination with environmental factors. The inheritance of these traits is not straightforward, and they are not necessarily passed down from only one parent, expressed only with dominant genes, or inherited with a specific probability.

Question 13

A person who has a genetic disorder that results from a chromosomal anomaly possesses:

Accepted Answer

A chromosomal anomaly refers to any change in the number or structure of chromosomes. Therefore, a person with a genetic disorder resulting from a chromosomal anomaly will have either more or fewer than the normal number of chromosomes. Option A is incorrect because the disorder is not necessarily caused by having two recessive genes. Option B is incorrect because the issue is with the chromosomes, not individual genes. Option C is also incorrect because the disorder is typically caused by the alteration of a single gene or region on a chromosome, not multiple genes.

Question 14

Psychological traits, such as empathy, aggression, and shyness, follow the _____ type of inheritance pattern.

Accepted Answer

Psychological traits are often influenced by multiple genes, meaning they are polygenic. Dominant-recessive inheritance and X-linked inheritance patterns typically involve single genes, and heterozygous refers to the genotype rather than the inheritance pattern.

Question 15

Which statement about autism spectrum disorder is TRUE?

Accepted Answer

Numerous studies have consistently shown that autism spectrum disorder (ASD) has a strong genetic component, and estimates of the genetic heritability of ASD range from 50-90%. Therefore, option D is the only true statement regarding the causes of ASD. Option A has been widely debunked as a myth, while option B oversimplifies the complex etiology of ASD. Option C underestimates the prevalence of ASD, as current estimates suggest that approximately 1 in 66 individuals in Canada and the United States are diagnosed with ASD.

Question 16

A disorder in which an individual is born with female genitalia but is found to be genetically male may be a result of:

Accepted Answer

A defect in regulator genes could affect the development of the sexual anatomy, resulting in a discrepancy between genetic and physical sex. This disorder is called androgen insensitivity syndrome (AIS), which affects the expression or function of genes that influence the body's response to androgens (male sex hormones). As a consequence, the fetus with XY chromosomes (i.e., male) may fail to develop male-typical genitalia and instead develop female-typical genitalia or ambiguous genitalia. This disorder is not caused by a faulty dominant-recessive pattern, Down syndrome, or a sex-linked disorder because it involves a different pathway of gene expression and hormone action.

Question 17

When several genes contribute to a particular phenotypic outcome, this is referred to as:

Accepted Answer

Polygenic inheritance occurs when multiple genes contribute to a particular phenotypic outcome. This is different from Mendelian inheritance, which involves the transmission of a single gene from one generation to the next, and from heterozygous inheritance, which refers to the inheritance of two different alleles for a single gene. Multifactorial expression refers to the interaction of genetic and environmental factors in determining a particular phenotype.

Question 18

Sex-linked disorders associated with the X chromosome are:

Accepted Answer

Sex-linked disorders associated with the X chromosome are typically caused by a mutation in a gene on the X chromosome. Because males only have one X chromosome, if they inherit a mutated gene on that chromosome, they will develop the disorder. Females have two X chromosomes, so even if one X chromosome has a mutated gene, they may still have a normal gene on the other X chromosome to compensate, resulting in a milder form of the disorder or no symptoms at all. Therefore, sex-linked disorders associated with the X chromosome are more likely to affect males.

Question 19

The influence of the child's _____ on his/her _____ represents the active child theme.

Accepted Answer

The active child theme refers to how a child's phenotype (observable characteristics) can influence and shape their environment.

Question 20

A clear relationship between the severity of the gene anomaly and the resulting phenotype is displayed by examining the genetic underpinnings of:

Accepted Answer

The answer of A clear relationship between the severity of...

Quiz 3: Biology and Behaviour