Download basic of the genetic

Basic words:
• GENOTYPE = complex of all hereditary information of
organism (all genes)
• PHENOTYPE = complex of visible outward signs and
characters, outer demonstration of the genotype
• ALLELE = one form of the gene
• HOMOZYGOUS = organism, which from perspective of
selected gene includes couple of alleles with coincident
function (for ex. aa, BB, ...)
• HETEROZYGOUS = organism, which perspective of
selected gene include couple of alleles with different
function (for ex. Aa, Bb)
In heterozygotes, for the phenotype demonstration is crucial
the functional relationship between different alleles:
– DOMINANT – allele is fully functional and rules over the
another
– RECESSIVE – nonfunctional allele, which is not
demonstrated in phenotype
• AUTOSOMAL HEREDITY = bounded to
nongender chromosomes - autosoms (for ex. Color
of eyes, hair, ...)
• GONOSOMAL HEREDITY = bounded to gender
chromosomes – gonosomes (for ex. daltonism,
haemophilia)
Some examples
• Mother has blue eyes. Allele for blue eyes is
recessive. Father has homozygous brown eyes.
Which colour of eyes will have their child?
• Answer:
P-generation: mother: aa
gamets:
a
F1 – generation:
x
x
father: AA
A
Aa
• Concluson: All childs will have heterozygous
brown eyes.
???
Ex.2:
Allele A response to create the green colour of peas,
allele a to create yellow color of peas.
Allele B demonstration circle shape of peas, while allele b
crisp shape.
Cross one with green circle shape peas, which is homozygous
and one with crisp shape yellow peas.
Answer: P-gen.:
gamets:
F1-gen:
AABB x aabb
AB,AB
ab, ab
AaBb (green circle shape, heterozygous)
We continue with crossing to next generation:
AaBb
x
AaBb
gamets:
AB,Ab,aB,ab
AB,Ab,aB,ab
We use for calculating combination square:
gamets
AB
Ab
aB
ab
AB
AABB
AABb
AaBB
AaBb
line of heterozygotes
Conclusion:
Ab
AAbB
AAbb
AabB
AAbb
aB
aABB
aABb
aaBB
aaBb
ab
aAbB
aAbb
aabB
aabb
line of homozygotes
Phenotype gender ratio 9 : 3 : 3 : 1
Gonosomal heredity – different from autosomal, (recessive
allele can demonstrate)
- is necessarily, if carrier of the
sign is father or mother
Example: Haemophilia is gonosomal bounded disease. Father
bleeder (haemophiler) married with healty woman. Set the
child if
a) woman is not uttering
b) woman is uttering
Answer: a)
P-gen:
Gamets:
F1-gen:
x
mother XX
father: XhY
Xh , Y
X, X
Xh X, Xh X, YX, YX
Conclusion of a):
Girls will by healty, but will uttering (Xh X)
Boys will by healty XY
b)
P-gen:
Gamets:
F1-gen:
father XhY
x
mother XXh
Xh , Y
X, Xh
XhX, XhXh , XY, XhY
Conclusion: 50% of girls will be healty but will
uttering (XhX), 50% of girls will ill (bleeder)
(XhXh).
50% of boys will be healthy (XY), 50%
will be ill (bleeder) (XhY).
Example:
Gene for brown eye color is dominant
to the gene for blue eye color.
Man with blue eyes marries broweyed woman, whose mother had
blue eyes.
What ratio of their children will
have blue eyes?
•
Man naemophilic marries his cousin.
Mothers of both partners were sisters,
whose father had haemophillia. Married
couple had one son, who had haemophillia,
two daughters, with haemophillia and one
healthy daughter.
– What were the genotypes of all family
memebers?
– What is the prognosis for the sons of ill
daughters?
– What is the prognosis for the sons of
healthy daughter?
Good luck to you at final test
☺