Question 1

A special molecule,_______,contains the genetic material of the organism.

Accepted Answer

DNA (deoxyribonucleic acid) is the primary molecule that carries the genetic information for most organisms. It is made up of four different nucleotide bases (adenine, guanine, cytosine, and thymine), which combine in specific sequences to code for specific genetic traits. Genes (B) are segments of DNA that contain the instructions for making specific proteins, while chromosomes (C) are structures made up of DNA and protein that contain many genes. Amine (D) refers to a class of organic compounds that are not directly related to genetic material.

Question 2

Silvia has blond hair,even though her mother and father each have brown hair.What do we know about Silvia's parents?

Accepted Answer

For Silvia to have blond hair, both of her parents must have at least one recessive gene for blond hair color. This means that they can each have a dominant gene for brown hair, but also carry a recessive gene for blond hair, which they could pass on to their offspring.

Question 3

At fertilization,the chromosomes from the father's sperm unite with the chromosomes from the mother's egg,creating a new cell called a(n)_______.

Accepted Answer

The new cell created at fertilization is called a zygote, which contains the full set of chromosomes (half from the father and half from the mother) and is the beginning stage of development for a new individual. The other choices may refer to later stages of development (embryo, blastocyst) or the complete set of genetic material (genome).

Question 4

What is the cause of Down syndrome?

Accepted Answer

Down syndrome is caused by an extra copy of the 21st chromosome, resulting in a total of three copies instead of the usual two. This genetic abnormality occurs randomly during fetal development and is the most common chromosomal disorder.

Question 5

A trait controlled by a dominant gene _______.

Accepted Answer

A dominant gene will always be expressed if it is present in at least one copy (allele), regardless of the other allele. If it is paired with a different allele, either dominant or recessive, it will still be expressed. Only if a trait is controlled by a recessive gene will it require two copies of that gene to be expressed. Therefore, choices B, C, and D are incorrect.

Question 6

A gene that actively controls the expression of a trait is called a _______ gene.

Accepted Answer

A dominant gene is able to control or influence the expression of a trait, even if only one copy is present in an individual's genome. In contrast, a recessive gene only expresses its effect if two copies are present, and a mutated gene has undergone some change or alteration that may or may not affect trait expression. A recombinant gene is a gene that has been artificially created or modified through genetic engineering techniques.

Question 7

Ovum is a term used to describe _______.

Accepted Answer

Ovum specifically refers to the female sex cell or egg.

Question 8

Steve was born a male with an extra X chromosome on the 23^rd pair.As result,he has reduced masculine characteristics,enlarged breasts,and is obese and excessively tall.Which disorder is likely to be diagnosed?

Accepted Answer

Klinefelter's syndrome is a genetic disorder caused by having an extra X chromosome in males (XXY). This results in reduced testosterone levels, which can lead to reduced masculine characteristics, enlarged breasts (gynecomastia), and obesity. In addition, individuals with Klinefelter's syndrome are generally taller than average. This description matches the symptoms of Steve, therefore Klinefelter's syndrome is the likely diagnosis.

Question 9

In _______ syndrome,the 21^st pair of chromosomes contains an extra chromosome resulting in symptoms such as wide-set almond-shaped eyes and mental retardation.

Accepted Answer

The extra chromosome in the 21st pair is characteristic of Down syndrome, and the symptoms mentioned (wide-set almond-shaped eyes and mental retardation) are common features of the syndrome. PKU is a genetic disorder that affects the body's ability to break down an amino acid called phenylalanine. Klinefelter's syndrome is a disorder in which males have an extra X chromosome, while Turner's syndrome is a disorder in which females are born with only one X chromosome.

Question 10

Diseases carried by recessive genes are inherited when _______.

Accepted Answer

Diseases carried by recessive genes require the individual to inherit two copies of the gene, one from each parent, in order for the disease to be expressed. This means that the child must inherit two recessive genes, one from each parent. Choices B, C, and D do not fulfill this requirement.

Question 11

A(n)_______ is a section of DNA containing a sequence of amines.

Accepted Answer

A gene is a section of DNA that codes for a specific protein or RNA molecule, and is made up of a sequence of nucleotides (not amines). Therefore, choice B is the best answer.

Question 12

How many pairs of chromosomes are normally in each cell of the human body?

Accepted Answer

Each human cell normally contains 23 pairs of chromosomes, for a total of 46 chromosomes.

Question 13

Ryan has cystic fibrosis.This means that his mother is a carrier for the cystic fibrosis gene,while his father _______.

Accepted Answer

Cystic fibrosis is an autosomal recessive disorder, meaning Ryan must inherit one defective gene from each parent. If Ryan has cystic fibrosis, both parents must at least be carriers, meaning his father must also be a carrier.

Question 14

Rod-shaped structures in the cell nucleus that contain genes are referred to as _______.

Accepted Answer

Chromosomes are rod-shaped structures in the cell nucleus that contain genes. DNA is the genetic material that makes up chromosomes. Sex-linked traits refer to genes that are located on the sex chromosomes, which determine an individual's sex. Amines are a type of organic molecule and are not directly related to chromosomes.

Question 15

Which of the following is a special molecule that contains the genetic material of the organism?

Accepted Answer

DNA is the special molecule that contains the genetic material of the organism. It is responsible for transmitting genetic information from one generation to the next. A gene is a specific sequence of DNA that carries the instructions for producing a particular protein. A chromosome is a structure composed of DNA and proteins that carries a large portion of an organism's genetic material. Amine is a type of organic molecule that contains a nitrogen atom bonded to hydrogen atoms.

Question 16

Sheila was born a female with only one X chromosome on the 23^rd pair.As a result,she is very short,infertile,and sexually underdeveloped.With which disorder is she likely to be diagnosed?

Accepted Answer

Turner's syndrome is caused by the absence of one X chromosome in females. The lack of a second X chromosome results in short stature, infertility, and underdeveloped sexual characteristics. Therefore, Sheila is likely to be diagnosed with Turner's syndrome. PKU is a metabolic disorder, while Down syndrome is caused by the presence of an extra chromosome. Klinefelter's syndrome is a genetic disorder caused by the presence of an extra X chromosome in males, so it is not likely to be the diagnosis for Sheila who is a female with only one X chromosome.

Question 17

Humans have a total of _______ chromosomes in normal developmental cases.

Accepted Answer

Humans have a total of 46 chromosomes in normal developmental cases. This is because there are 23 pairs of chromosomes, one set inherited from each parent.

Question 18

A gene that only influences the expression of a trait when paired with another less active gene is called _______.

Accepted Answer

A gene that only influences the expression of a trait when paired with another less active gene is typically a recessive gene. This means that its effects are only seen when an individual has two copies of the gene (one from each parent) that are both less active. In contrast, dominant genes can be expressed even if an individual only has one copy of the gene. The other options (B and C) do not accurately describe this type of gene.

Question 19

Which of the following is defined as a gene that controls the appearance of a certain trait?

Accepted Answer

A gene that controls the appearance of a certain trait is called a dominant gene. Dominant genes are expressed even if the individual has only one copy of the gene, while recessive genes are only expressed if the individual has two copies of the gene. Mutated genes are genes that have undergone a change in their DNA sequence, and recombinant genes are genes that have been artificially modified through genetic engineering techniques.

Question 20

In _______ syndrome,the 23^rd pair of chromosomes is missing an X,resulting in short,infertile females.

Accepted Answer

Turner's syndrome is caused by the complete or partial absence of one of the two X chromosomes in females, resulting in short stature, infertility, and other physical and developmental abnormalities. The other options, PKU, Down syndrome, and Klinefelter's syndrome, are caused by different genetic mutations or abnormalities and do not involve the loss of an X chromosome.

Quiz 8: Development Across the Life Span

A special molecule,_______,contains the genetic material of the organism.

Silvia has blond hair,even though her mother and father each have brown hair.What do we know about Silvia's parents?

At fertilization,the chromosomes from the father's sperm unite with the chromosomes from the mother's egg,creating a new cell called a(n) _______.

What is the cause of Down syndrome?

A trait controlled by a dominant gene _______.

A gene that actively controls the expression of a trait is called a _______ gene.

Ovum is a term used to describe _______.

Steve was born a male with an extra X chromosome on the 23^rd pair.As result,he has reduced masculine characteristics,enlarged breasts,and is obese and excessively tall.Which disorder is likely to be diagnosed?

In _______ syndrome,the 21^st pair of chromosomes contains an extra chromosome resulting in symptoms such as wide-set almond-shaped eyes and mental retardation.

Diseases carried by recessive genes are inherited when _______.

A(n) _______ is a section of DNA containing a sequence of amines.

How many pairs of chromosomes are normally in each cell of the human body?

Ryan has cystic fibrosis.This means that his mother is a carrier for the cystic fibrosis gene,while his father _______.

Rod-shaped structures in the cell nucleus that contain genes are referred to as _______.

Which of the following is a special molecule that contains the genetic material of the organism?

Sheila was born a female with only one X chromosome on the 23^rd pair.As a result,she is very short,infertile,and sexually underdeveloped.With which disorder is she likely to be diagnosed?

Humans have a total of _______ chromosomes in normal developmental cases.

A gene that only influences the expression of a trait when paired with another less active gene is called _______.

Which of the following is defined as a gene that controls the appearance of a certain trait?

In _______ syndrome,the 23^rd pair of chromosomes is missing an X,resulting in short,infertile females.

Quiz 8: Development Across the Life Span

A special molecule,_______,contains the genetic material of the organism.

Silvia has blond hair,even though her mother and father each have brown hair.What do we know about Silvia's parents?

At fertilization,the chromosomes from the father's sperm unite with the chromosomes from the mother's egg,creating a new cell called a(n) _______.

What is the cause of Down syndrome?

A trait controlled by a dominant gene _______.

A gene that actively controls the expression of a trait is called a _______ gene.

Ovum is a term used to describe _______.

Steve was born a male with an extra X chromosome on the 23rd pair.As result,he has reduced masculine characteristics,enlarged breasts,and is obese and excessively tall.Which disorder is likely to be diagnosed?

In _______ syndrome,the 21st pair of chromosomes contains an extra chromosome resulting in symptoms such as wide-set almond-shaped eyes and mental retardation.

Diseases carried by recessive genes are inherited when _______.

A(n) _______ is a section of DNA containing a sequence of amines.

How many pairs of chromosomes are normally in each cell of the human body?

Ryan has cystic fibrosis.This means that his mother is a carrier for the cystic fibrosis gene,while his father _______.

Rod-shaped structures in the cell nucleus that contain genes are referred to as _______.

Which of the following is a special molecule that contains the genetic material of the organism?

Sheila was born a female with only one X chromosome on the 23rd pair.As a result,she is very short,infertile,and sexually underdeveloped.With which disorder is she likely to be diagnosed?

Humans have a total of _______ chromosomes in normal developmental cases.

A gene that only influences the expression of a trait when paired with another less active gene is called _______.

Which of the following is defined as a gene that controls the appearance of a certain trait?

In _______ syndrome,the 23rd pair of chromosomes is missing an X,resulting in short,infertile females.

Steve was born a male with an extra X chromosome on the 23^rd pair.As result,he has reduced masculine characteristics,enlarged breasts,and is obese and excessively tall.Which disorder is likely to be diagnosed?

In _______ syndrome,the 21^st pair of chromosomes contains an extra chromosome resulting in symptoms such as wide-set almond-shaped eyes and mental retardation.

Sheila was born a female with only one X chromosome on the 23^rd pair.As a result,she is very short,infertile,and sexually underdeveloped.With which disorder is she likely to be diagnosed?

In _______ syndrome,the 23^rd pair of chromosomes is missing an X,resulting in short,infertile females.