Chapter 24 Flashcards
The genes for cystic fibrosis are located on chromosome number
7
Cystic fibrosis is a hereditary disease that causes scar tissue to form in several organs, from nucleotide positioning techniques, it has been correlated with chromosome 7
Name 3 things true of chromosomes
Contain DNA
Coated with histones
46 mitotic cells
Chromosomes become visible only when they are condensed during active division, they r comprised of DNA molecules coated with histone protiens
Huntington disease is associated with chromosome
4
Huntington’s disease is a neurological condition with seizures and psychological alterations, associated with chromosome number 4
When does the chromosome number reach 92
Before prophase
What term refers to the inheritance of traits that require 2 genes
Recessive
When a physician questions a patient about their family history, they are gathering evidence to construct a
Pedigree
How is familial hypercholesterolemia usually inherited
Incomplete dominance
High blood cholesterol has been linked to defective LDL liver receptors, inherited by incomplete dominance
Diseases that display different symptoms and signs for the same disease are displaying
Pleiotropy
Heterogeneity refers to the expression of a phenotype by many different genes
The the SRY gene causes expression of ? Chromosome gene
X
The sex determining gene on the Y chromosome causes expression of traits for sex on the X
What is an example of a codominant trait in humans
ABO blood groups
Codominance means that both alleles can be expressed. As in the blood type AB
Traits that are controlled by one or more genes and influenced by the influence by the environment are said to be
Multifactorial
When both genes and environment play a role in a trait it has many factors
The fact that a woman cannot generally grow a beard is because beard growth is a ? Trait
Sex-limited
Sex-limited traits occur in certain sexes, usually due to hormonal influence
The normal chromosome number is referred to as
Euploid
Eu means normal
The last pair of 23 chromosomes is referred to as the
Sex chromosomes
The 23rd pair of chromosomes is the X and/or Y chromosomes
Which chromosomes indicate a normal male fetus
XY
A normal male is XY. XX is female
Persons with dark skin who produce offspring with the same color have genes that are probably
Homozygous for melanin enzymes
Homozygous alleles are pairs of genes on two chromosomes, one from each parent, that contain the same information for a specific protein synthesis
Name 3 organ systems significantly affected by cystic fibrosis
Pulmonary
Gastrointestinal
Reproductive
Sickle cell genes are present in ?% of the American population with Central African ancestry
8%
About 8% of Americans with Central Africa ancestry have the sickle cell anemia gene but only 1 out of every 170 children develop sickle cell anemia
When will a person with sickle cell trait develop symptoms
Under hypoxia
During times when the oxygen tension is low, the red blood cells may sickle and distort, blocking capillaries, exercise may not be a sufficient provocation
The genes for the ABO blood types are
Codominant
The genes for the ABO blood antigens are co-dominant and appear on multiple allele chromosome position
Persons with blood type B have the ? Agglutinogens (antigen)
B
Since the ABO blood types are inherited as co-dominants, a person with phenotype B must have only agglutinogen (antigens) B on their erythrocyte membranes
What blood type could these parents NOT produce in their children, AO and BB
O
The final height of a child is determined by
Polygenic inheritance
The height of individuals or variations in skin tone is inherited in a polygenic pattern with many genes involved in complex arrangements, a child can be quite different from their parents
Name 3 things that affect the expression in an individual with a homozygous recessive trait
The health of the mother
Disease in the father
Diet
The expression of genes is an interaction among gene DNA potentials and the ability to allow development of traits, given the influence of environmental factors such as diet or health.
The result of meiosis is to produce
23 chromosomes
Traits only transferred from fathers to their sons are associated with the ? Chromosome
Y
Traits on the X chromosome may be given to males or females