CHAPTER 9
INTRO TO GENETICS
_________________________________ -FATHER OF GENETICS
________________________-STUDY OF HEREDITY
________________________-PASSING OF CHARACTERISTICS FROM PARENT TO
OFFSPRING
______________________-INHERITED CHARACTERISTIC
______________________-PURE FOR A TRAIT
___________________________________ -produced offspring whose parents differed by one
trait (height)
Offspring were called _____________________________.
RULES TO REMEMBER
1. EACH PERSON RECIEVES TWO COPIES OF A GENE -ONE FROM EACH
PARENT -WHEN REPRODUCTION TAKES PLACE.
2. THERE ARE ALTERNATE FORMS OF A GENE CALLED __________________.
YOUR TRAITS ARE DETERMINED BY THE ALLELES YOU RECEIVE FROM YOUR PARENTS
3. WHEN TWO ALLELES OCCUR TOGETHER, ONE OF THEM MAY BE
EXPRESSED (PHYSICALLY SEEN) WHILE THE OTHER MAY NOT BE
OBSERVED IN THE ORGANISM’S APPEARANCE (HIDDEN)
a. The expressed gene is called the ______________________________.
(represent by capital letters)
b. The hidden gene is called the _________________________________.
(represented by lower case letters)
4. ______________________________________- When gametes are formed during
meiosis, the alleles separate so that each gamete receives only one allele for each
trait.
5. If the two alleles of a gene are the same the individual is said to be
______________________ (TT tt)
6. If the two alleles of a gene are different the individual is said to be
___________________________ (Tt)
7. The set of alleles an organism receives from their parents is called the
_____________________.
8. The physical appearance of an organism (which is determined by the genotype) is
called the _____________________.
9. _______________________- Diagram that predicts the possible genotypes and
phenotypes of offspring
10. _______________________ crosses (DI=2) Cross that involves parents who differ
by two traits
11. __________________________________________-the inheritance of one trait had no
effect on the inheritance of another trait.
Complex Patterns of Heredity and Human Genetics
I.
Incomplete Dominance- The phenotype of the heterozygous is
___________________________ between those of the two homozygous individuals.
II.
Codominance
a. The phenotypes of both homozygous individuals are visible in _____________________
individuals.
b. __________________ alleles are expressed equally.
c. Example of Codominance in Humans
i. Sickle cell carriers
ii. Heterozygous individuals have normal and sickle shaped cells.
iii. Carry sickle cell trait and can pass on to offspring.
A A
I I
IA i
IB IB
IB I
IA IB
ii
Homo
Heter
Homo
Heter
Codominat
O (recessive)
III.
Multiple Alleles
a. Traits controlled by more than ________________ alleles.
b. EX: blood type- A, B, AB, O
1. Mixing incompatible blood causes __________________ in death.
2. Determining ______________________
IV.
Sex-Linked Traits
a. Traits controlled by genes located on ________________ chromosomes (X or Y) are sexlinked traits.
b. The alleles for sex-linked traits are written as superscripts (XR Y, XR YR )
c. Traits carried on Y chromosomes are only passed from a ___________________ to his
son.
d. X-linked traits can be passed to a son or a daughter from a mother or a father.
i. Sex-linked traits in humans
1. ___________________________-(X-linked disorder) Can’t differentiate between
red and green.
2. ___________________________-(X-linked disorder) Inability to ___________.
Males inherit from carrier mothers.
V.
Polygenic Inheritance
a. The inheritance of a trait that is controlled by two or more ______________ that may or
may not be on the same chromosome.
i. ________________________________
ii. ________________________________
iii. ________________________________
VI.
Environmental Influences
a. The _________________ makeup determines an organisms potential to develop and
function.
b. Many factors can influence how a gene is expressed.
i. External
1. ______________
3. ______________
2. ______________
4. ______________
ii.
VII.
Internal
1. ______________________
2. ______________________
Simple Recessive Heredity
a. ____________________________________
b. ____________________________________
c. ____________________________________
VIII.
Simple Dominant Heredity
3. _________________
a. ____________________________________
CHAPTER 12
PEDIGREES AND GENETIC DISORDERS
I.
______________________-DIAGRAM THAT SHOWS HOW A TRAIT IS INHERITED
OVER SEVERAL GENERATIONS
II.
PEDIGREE SYMBOLS
a. MALES=SQUARES
b. FEMALES=CIRCLES
c. PARENTS=HORIZONTAL LINE BETWEEN CIRCLE AND SQUARE
d. OFFSPRING=VERTICAL LINES
e. ROMAN NUMERALS=GENERATIONS
f. DEATH=SHADED CIRCLE OR SQUARE WITH A LINE CROSSING
g. CARRIER=HALF-SHADED CIRCLE OR SQUARE
III.
___________________-PERSONS WITH THE RECESSIVE ALLELE BUT DO NOT
HAVE THE DISEASE/TRAIT; CARRIERS DO NOT EXPRESS THE DISEASE BUT
THEY CAN PASS IT TO THEIR OFFSPRING
IV.
____________________ ________________________
a. DISEASES OR DISABLING CONDITIONS THAT HAVE A GENETIC BASIS
b. MOST GENETIC DISORDERS ARE CAUSED BY _______________________
ALLELES
1. CYSTIC FIBROSIS
2. SICKLE CELL ANEMIA
3. TAY-SACHS
4. PHENYLKETONURIA (PKU)
5. HEMOPHILIA
V.
VI.
VII.
c. DOMINANT GENETIC DISORDERS
i. A SINGLE DOMINANT ALLELE IS REQUIRED TO INHERIT THE
DISORDER
1. ___________________________
2. HARMLESS DOMINANT TRAITS
a. TONGUE ROLLING
b. HITCHHIKER’S THUMB
c. FREE EARLOBES
d. MIDDIGITAL HAIR
DETECTING GENETIC DISEASE
a. ______________________________________ -AN TEST OF A PERSON’S GENETIC
MAKEUP TO DIAGNOSE GENETIC DISORDERS
i. BLOOD TESTS
ii. DNA TESTS
iii. ____________________________-PICTURE OF CHROMOSOMES (DURING
METAPHASE) THAT ARE MADE FROM A BLOOD SAMPLE
iv. _____________________________-ANALYZE FETAL CELLS FROM
AMNION FLUID
TREATING GENETIC DISEASE
a. ____________________________________PLACE A HEALTHY COPY OF THE
GENE INTO THE CELLS OF A PERSON WHO HAS A DEFECTIVE GENE
_______________________________________________
a. INFORMING A PERSON/COUPLE ABOUT THEIR GENETIC MAKEUP
b. INFORMS COUPLES ABOUT THE PROBLEMS THAT MIGHT AFFECT THEIR
OFFSPRING