CHAPTER 27: APPLIED GENETICS

27-1: MUTATIONS

Sources of Variation

Most variation is due to ______________ and _________________ during ____________ and _______________ during _____________.

Differences in DNA of a population can also be traced back to mutations, or _____________________________________________ _____________________________________________________.

Mutations may have different effects on a population:

DeVries first observed mutations in a plant, the ___________________

Kinds of Mutations

Mutants – __________________________________________.

1.         Chromosomal Mutation:

·       Changes in Chromosome Structure

ΰ Translocation –

ΰ Inversion –

ΰ Addition –

ΰ Deletion –

·       Nondisjunction – ________________________________. Occurs when __________________________ properly during _________. (Ex: Down Syndrome, Turner Syndrome)

·       Polyploidy – Cells have some ______________________ ___________________. Occurs when _________________ _________________________ properly during ________________________.  (Ex: if a human had 69 chromosomes). Happens often in _____ (3n, 4n, 5n).

2.         Gene Mutation – ___________________________________ (the order of nucleotide bases).

Change in DNAΰ change in RNAΰ could make _____________

DNA mutations are ______________ and passed down to new cells.

·       Point Mutation – _________________________________ ________________. This mutation may change the resulting protein ΰ ________________________________.

·       Frameshift Mutation – _____________________________  ________________________________________________

ΰ Mutations in individual ______________ ΰ ____________ (can’t function without proper protein)

ΰ Mutations in _____________ ΰ ____________ of resulting embryo will have it

ΰ 1/100 mutations are dominant (_________________________)

ΰ _______ mutations are ____________. Defective gene ΰ ____/ ________________________

Jumping Genes

·       Genes that move or ______________________________________

·       When a gene moves to another gene during DNA replication, that _____________________________

·       Important source of ________________

·       _________________ – 1983, nobel prize

27-2: HUMAN GENETIC DISORDERS

Pedigree Chart –

A pedigree for Colorblindness (sex-linked recessive):

Pedigrees allow geneticists to:

·       Determine the ___________________________ of a trait (autosomal/ sex-linked, dominant/recessive)

·       ________________________________________ of potential offspring in a family

Modes of Inheritance

1.         Sex-Linked Inheritance

·       Carried on ____-chromosome; ______________ than females affected

·       Most sex-linked diseases are ________________

Sex-Linked Disorders:

ΰ Hemophilia – lack blood-clotting protein; ________________

ΰ Duchenne Muscular Dystrophy – Inactive form of a protein for normal muscle function; _______________________________

ΰ Color-blindness – _______________________________

2.         Autosomal Inheritance – Carried on _____________________

Recessive Traits:

·       __________________________

·       Usually __________________________

·       Usually appears in ____________ family members

  Autosomal Recessive Disorders:

  ΰ Sickle Cell Anemia –

v   RBC clump ΰ block blood vessels ΰ _______________ _______________________ ΰ pain and weakness

v   Caused by ______________________________________ __________________ protein

v   __________________________ ΰ mRNA _________ changes ΰ _____________ changes ΰ ______________

v   GAA ΰ GUA (__________ instead of ________________)

v   Can be traced back to African ancestry because ________ __________________________________________

ΰ Phenylketonuria (PKU) –

v   Phenylalanine breaks down into _____________________ ________________________ and cause mental retardation

v   Diagnose with infants’ urine; Treatment = ______________

ΰ Tay Sach’s Disease –

v   _______ build up in the _____________ and ________ them

v   Found mostly in Eastern ______________________ families

ΰ Cystic Fibrosis –

v   Some glands produce ________________ that clogs and ________________________

v   __________________

v   ___________________________ ancestry

Dominant Traits

·       Usually _________________________

·       Usually appear in ___________ of the family members

Autosomal Dominant Disorders ΰ only need _____________ to be affected.

ΰ Huntingtons Disease –

v   __________________________ (30’s)

Chromosomal Disorders

v   Down Syndrome – _________________________ (47,XX/XY+21)

v   Turner Syndrome – ____________________________ (45,X)

v   Klinefelter Syndrome – ___________________________ (47,XXY)

Chromosomal disorders can be detected by analyzing a Karyotype – a ________________________________________________________.

Cells from a fetus may be obtained by:

1.         Amniocentesis – A long needle is inserted into the __________ _____ at _________ weeks ΰ _________________ are drawn

2.         CVS – A sample of _______________________________ are removed (____________ weeks)

Fetuses may be observed or monitored through:

v   Ultrasound –

v   Fetoscopy –

27-3: GENETIC ENGINEERING

Breeding Methods –

1.         Selection –

2.         Inbreeding –

·       Produces ______________________________

·       _____________________, increases homozygous genes (tt)

·       Danger:__________________________________________ ___________ and expressed (German Shepards = bad hips)

3.         Hybridization –

Hybrid vigor – Hybrid offspring are usually _________________ ______________________, but are usually __________ (mules).

4.         Mutations –

Ex: Polyploid plants (bigger, hardier, more productive)

Methods of Genetic Engineering

Step 1: Isolating a Gene ΰ

Step 2: Making Recombinant DNA ΰ

·       Plasmids –

·       Plasmids are ____ with restriction enzymes, producing _________ ________ ΰ sticky ends are now __________________________ _______________ (foreign DNA)

·       _______________ (enzyme) splices the desired ______ into the open __________

·       Recombinant DNA –

Step 3: DNA Insertion ΰ

Step 4: DNA Sequencing ΰ

Applying Genetic Engineering

·       Using genetic engineering to ______________________________ _______________ (interferon, insulin) in ____________________.

·       Gene Therapy –

The gene is inserted into cells using a _______ (deactivated virus).

·       Farmers ______________________________________________ _____________________________________________

The Human Genome

Genome –

Human Genome Project –

·       ____________________ associated with genetic disorders ΰ __________________________ disease

Ethics and Human Genetics

How should genetic engineering be used? Who should decide the rules? Answer these questions posed on p. 561 of textbook.