Chapter 3 Flashcards
EXPLAIN
What is a monozygotic twin?
Twins that were born from the same zygote, that divided in order to form 2 genetically identical twins
often referred to as identical twins
EXPLAIN
What is a Dizygotic twin?
When 2 ova/eggs are released stimutaneiously and are each fertilized, resulting in genetically unique twins
Often referred to as fraternal twins
EXPLAIN
If someone has XX chromosomes on their 23rd pair, are they male or female?
Female
hint: remember the x’s by the number of ‘e’ in the term
EXPLAIN
If someone has XY chromosomes on their 2rd pair, are they male or female?
Male
hint: remember the x’s by the number of ‘e’ in the term
EXPLAIN
Who provides the 2nd X or Y to the 23rd pair to determine the sex of the child?
The male
EXPLAIN
What is the function of genes in development in utero?
- 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
DEFINE
Allele
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
EXPLAIN
What do Alleles do?
Influence the characteristics that are developing
EXPLAIN
What is the difference between a dominant allele and a recessive allele?
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
DEFINE
Sex-linked inheritance
Characteristics that are associated with with genes on the sex chromosome
Typically on the X chromosome
DEFINE
Polygenetic Inheritance
Characteristics that are influenced by multiple pairs of alleles rather than one specific pair
DEFINE
Epigenetics
A modification of gene expression that has no effect on DNA
DEFINE
Cogenital Disorder
A condition that you are born with
may not always be apparent when born
EXPLAIN
What causes chromosomal abnormalities?
Cell division during meiosis results in an uneven distribution of chromosomes
LIST
What are the 2 sex chromosomes disorders discussed that affect females?
Turner Syndrome
Poly-X Syndrome
EXPLAIN
What is Turner Syndrome?
In the context of chromosomes
When a female has one healthy X chromosome and then the other is missing, damaged or otherwise affected
written as: XO
EXPLAIN
What is Poly-X syndrome?
In the context of chromosomes
When a female is born with an additional X chromosome on their sex chromosome
LIST
What are the 2 sex chromosome disorders discussed that affect males?
Klinefelter Syndrome
Supermale Syndrome
EXPLAIN
What is Klinefelter Syndrome?
In the context of chromosomes
Males born with an extra X on their sex chromosome
may have multiple extras
EXPLAIN
Supermale Syndrome
In the context of chromosomes
When a male is born with an extra Y
May have multiple extras
DEFINE
Autosomes
Autosomes are the first 22 pairs of chromosomes
EXPLAIN
What is Down Syndrome?
May also be referred to ask Trisomy 21
When someone is born with an extra 21st chromosome
EXPLAIN
Are genetic abnormalities associated more often with recessive or dominant alleles?
Recessive
LIST
Name the 3 disordered discussed that are associated with recessive alleles
Both parents are carriers but may not have the condition
- Cystic Fibrosis
- Diabetes
- Hemophilia
EXPLAIN
What disease was discussed that is associated with dominant alleles?
One or both parents are carriers, and both will have the disease
Huntington’s Disease
EXPLAIN
What are the 4 prenatal detection techniques for conditions?
- Amniocentesis: Analysis of amniotic fluid
- Chorionic Villus Sampling: Extraction and analysis of fetal cells from Chorion
- Non-invasive Prenatal Testing: Assessing fragment of cell-free DNA in mother’s blood stream
- Ultrasound: Scan of womb using sound waves
EXPLAIN
Whats the difference between a genotype and Phenotype?
Genotype is the inherited genes, while Phenotype is the traits that present due to the genotype
DEFINE
Heritability
The variability in a trait that is attributed to hereditary influence
EXPLAIN
How can heritability be determined?
Selective breeding experiments or family studies
DEFINE
Concordance Rates
Percentage of pairs in which both display a given trait
