Chapter 3

Question 1

EXPLAIN

What is a monozygotic twin?

Answer 1

Twins that were born from the same zygote, that divided in order to form 2 genetically identical twins

often referred to as identical twins

Question 2

EXPLAIN

What is a Dizygotic twin?

Answer 2

When 2 ova/eggs are released stimutaneiously and are each fertilized, resulting in genetically unique twins

Often referred to as fraternal twins

Question 3

EXPLAIN

If someone has XX chromosomes on their 23rd pair, are they male or female?

Answer 3

Female

hint: remember the x’s by the number of ‘e’ in the term

Question 4

EXPLAIN

If someone has XY chromosomes on their 2rd pair, are they male or female?

Answer 4

Male

hint: remember the x’s by the number of ‘e’ in the term

Question 5

EXPLAIN

Who provides the 2nd X or Y to the 23rd pair to determine the sex of the child?

Answer 5

The male

Question 6

EXPLAIN

What is the function of genes in development in utero?

Answer 6

• produce the amino acids that are necessary for forming new cells
• guide cells to develop different parts of the body
• Regulate the pacing of development

Question 7

DEFINE

Allele

Answer 7

a set of two or more genes that may occur alternatively at a given site on a chromosome

an Allele consists of 1 gene from each parent

Question 8

EXPLAIN

What do Alleles do?

Answer 8

Influence the characteristics that are developing

Question 9

EXPLAIN

What is the difference between a dominant allele and a recessive allele?

Answer 9

A dominant allele is an allele that only requires one in the set to be expressed a trait, while for a recessive allele to be expressed they both must be recessive

Question 10

DEFINE

Sex-linked inheritance

Answer 10

Characteristics that are associated with with genes on the sex chromosome

Typically on the X chromosome

Question 11

DEFINE

Polygenetic Inheritance

Answer 11

Characteristics that are influenced by multiple pairs of alleles rather than one specific pair

Question 12

DEFINE

Epigenetics

Answer 12

A modification of gene expression that has no effect on DNA

Question 13

DEFINE

Cogenital Disorder

Answer 13

A condition that you are born with

may not always be apparent when born

Question 14

EXPLAIN

What causes chromosomal abnormalities?

Answer 14

Cell division during meiosis results in an uneven distribution of chromosomes

Question 15

LIST

What are the 2 sex chromosomes disorders discussed that affect females?

Answer 15

Turner Syndrome
Poly-X Syndrome

Question 16

EXPLAIN

What is Turner Syndrome?

In the context of chromosomes

Answer 16

When a female has one healthy X chromosome and then the other is missing, damaged or otherwise affected

written as: XO

Question 17

EXPLAIN

What is Poly-X syndrome?

In the context of chromosomes

Answer 17

When a female is born with an additional X chromosome on their sex chromosome

Question 18

LIST

What are the 2 sex chromosome disorders discussed that affect males?

Answer 18

Klinefelter Syndrome
Supermale Syndrome

Question 19

EXPLAIN

What is Klinefelter Syndrome?

In the context of chromosomes

Answer 19

Males born with an extra X on their sex chromosome

may have multiple extras

Question 20

EXPLAIN

Supermale Syndrome

In the context of chromosomes

Answer 20

When a male is born with an extra Y

May have multiple extras

Question 21

DEFINE

Autosomes

Answer 21

Autosomes are the first 22 pairs of chromosomes

Question 22

EXPLAIN

What is Down Syndrome?

May also be referred to ask Trisomy 21

Answer 22

When someone is born with an extra 21st chromosome

Question 23

EXPLAIN

Are genetic abnormalities associated more often with recessive or dominant alleles?

Answer 23

Recessive

Question 24

LIST

Name the 3 disordered discussed that are associated with recessive alleles

Both parents are carriers but may not have the condition

Answer 24

1. Cystic Fibrosis
2. Diabetes
3. Hemophilia

Question 25

# EXPLAIN What disease was discussed that is associated with dominant alleles? | One or both parents are carriers, and both will have the disease

Answer 25

Huntington's Disease

Question 26

# EXPLAIN What are the 4 prenatal detection techniques for conditions?

Answer 26

1. **Amniocentesis**: Analysis of amniotic fluid 2. **Chorionic Villus Sampling**: Extraction and analysis of fetal cells from Chorion 3. **Non-invasive Prenatal Testing**: Assessing fragment of cell-free DNA in mother's blood stream 4. **Ultrasound**: Scan of womb using sound waves

Question 27

# EXPLAIN Whats the difference between a genotype and Phenotype?

Answer 27

**Genotype** is the inherited genes, while **Phenotype** is the traits that present due to the genotype

Question 28

# DEFINE Heritability

Answer 28

The variability in a trait that is attributed to hereditary influence

Question 29

# EXPLAIN How can heritability be determined?

Answer 29

Selective breeding experiments or family studies

Question 30

# DEFINE Concordance Rates

Answer 30

Percentage of pairs in which both display a given trait