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TRANSCRIPT
Name: _____________________________ Date: _______________ Period: _________________
Notes: Gene Linkage, Polyploidy and Basic Patterns of Human Inheritance
Genetic Recombination: ● Remember ________________ ________________ is the exchange of genes between homologous
chromosomes during _______________ of meiosis.
● The new combination of genes produced by crossing over and independent assortment is called
______________________ _____________________.
Gene Linkage:● Gregor Mendel’s ___________________________________ states that when two or more traits are
inherited, individual traits are transmitted _____________________ of one another, giving different
traits an equal opportunity of occurring together.
● The _____________of genes on a chromosome results in an exception to Mendel’s law of independent
assortment because linked genes usually do not segregate___________________.
● _______________ ____________ occurs more frequently between genes that are _______ apart than
those that are ___________ together.
● A drawing called a _________________
_____________ shows the sequence of genes on a
chromosome and can be created by using crossover
data.
Polyploidy:● ______________ is the occurrence of having more than ______ paired
(homologous) sets of ___________________. Most eukaryotes are
______________, meaning they have two sets of chromosomes—one set
inherited from each parent.
● A _____________________ organism, for instance, would be designated
3n, which means that is has __________ sets of chromosomes.
○ Examples: ______________________ and __________________
Recessive Genetic Disorders in Humans● A recessive trait is expressed when the individual is _______________ _________________ (____) for
the trait.
● Therefore, those with at least one ________________ (___) allele will not express the
______________ (___) trait.
● An individual who is _________________ (____) for a recessive disorder is called a ______________.
Cystic Fibrosis
● Cystic fibrosis is a progressive, genetic disease that causes persistent _______ infections and limits the ability to_________ over time.
○ It affects the _____________ producing glands, digestive enzymes, and sweat glands.
○ Chloride ions are not absorbed into the cells of a person with cystic fibrosis but are excreted in
the sweat.
○ Without sufficient chloride ions in the cells, a thick _______________is secreted.
Albinism● Caused by altered genes, resulting in the absence of the skin pigment ______________ in _________
and ___________.
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Tay-Sachs Disease● Tay-Sachs is a rare inherited disorder that progressively destroys ____________ cells (___________)
in the brain and spinal cord.
○ Caused by the absence of the _______________ responsible for breaking down fatty acids
called _____________________.
○ Gangliosides accumulate in the brain, __________________ brain nerve cells and causing
______________ ______________________.
Galactosemia● Recessive genetic disorder characterized by the inability of the body to digest the sugar ___________.
○ During digestion, an enzyme (GALT) breaks down lactose from __________ into galactose and
glucose.
○ Persons with galactosemia lack or have defective GALT and should avoid ________ ________.
Dominant Genetic Disorders in Humans● ________________ _____________ is a fatal genetic disorder that causes the progressive breakdown
of nerve cells in the brain.
● ________________________ (a form of dwarfism) is a genetic condition that causes small body size
and limbs that are comparatively short.
Pedigrees
● A ________________ is a diagram that traces the _________________of a particular trait through
several generations.
Inferring Genotypes and Predicting● Inferring Genotypes
○ Knowing _______________ ____________ can determine what genes an individual is most
likely to have.
● Predicting Disorders
○ Record keeping helps scientists use _____________ ____________ to study inheritance
patterns, determine _____________, and determine ____________________.