Life Science Chapter 5 – Modern Genetics
Human traits are controlled in 3 different ways

By single genes with _______

By single genes with _______

By many genes that _______
1. Single genes w/2 alleles

Example: _______
 inherited by _______, _______, or _______
2. Single genes w/multiple alleles
 example: _______
 even though more than 2 alleles, a person can only have _______
3. Many genes (_______)
 exampels: _______
 anything with a wide range of phenotypes
Some genes are inherited together
Sex chromosomes

1 of the _______ pairs of chromosomes

XX=_______ XY=_______

Carry genes that determine gender and some other traits as well.
 Father’s sperm determines gender of baby, because mother can only donate an
_______
Sex-linked genes – carried on _______

X is bigger than Y so there are many genes on the X that are not present in the Y chromosome
 examples_______

Trait still has dominant and recessive alleles

Carrier – _______
Genetic disorder – _______. Caused by _______ or _______

Cystic fibrosis – _______. Caused by _______.

Sickle-cell disease – _______. Person has pain and is very tired.

Hemophilia – _______. Caused by _______.

Down syndrome – _______.
Pedigree – _______.

Circle is _______, square is _______

Filled in means _______ (homozygous recessive)

Empty means _______

Half means _______ (only females on sex-linked diseases–why?)
Help:


Karyotype – _______.

Genetic counseling – help understand chances of passing on disease using karyotypes, pedigrees, and punnett squares

Support groups, special treatments and doctors…
Developing organisms with desirable traits
Selective breeding - _______ (corn in Mexico, save the seeds from the best plants for next year)
1. inbreeding – _______ (crossing plump turkeys to make more plump turkeys).
Because they are so similar it increases the probability that they will inherit alleles that lead to genetic disorders (hip dysphasia in goldens…)
2. hybridization – _______ (schnoodles).
Cloning – _______. Easy with plants.
Genetic engineering – genes from 1 organism are transferred into the DNA of another.
1. _______ – used to make insulin. Put human DNA into bacteria and the human DNA codes for insulin
2. other organisms – create frost-resistant or pest-resistant crops, or help people with hemophilia.
3. _______ - remember from viruses, use viruses to ‘infect’ a person with healthy DNA
Human genome project – _______.