Bio 1201 Final Exam (Patterns of Inheritance) Kevin Oley
Terms in this set (35)
Location of a gene on a chromosome
An organism that has two identical alleles for a trait
An organism's physical appearance, or visible traits.
genetic makeup of an organism
Parental generation, the first two individuals that mate in a genetic cross
the first generation of offspring obtained from an experimental cross of two organisms
Shows both dominant traits
offspring of the F1 generation
Traits are in a 9:3:3:1 ratio
Situation in which one allele is not completely dominant over another allele
Ex. red flower + white flower = pink flower (blending)
Phenotypes are blended NOT genotypes
Both alleles are expressed
Ex. red flower + white flower = red and white spotted flower
Ex. ABO blood type, A and B are codominant
The ability of a single gene to have multiple effects.
Ex. sickle cell anemia
Early concept of heredity proposing that particles carry genetic information from different parts of the body to the reproductive organs.
parental traits blend such that their offspring have intermediate traits
Doesn't explain variation of traits (one eye color)
Augustinian monk and botanist whose experiments in breeding garden peas led to his eventual recognition as founder of the science of genetics (1822-1884)
What does it mean to breed true?
Parents would breed offspring that carry the same phenotype
Occurs in self pollinating plants
A cross between individuals that involves one pair of contrasting traits
One form disappears in the first gen but reappears for the second gen
A cross between individuals that have different alleles for the same gene
the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype
3:1 ratio represents?
Monohybrid cross given complete dominance of one allele over the other
9:3:3:1 ratio represents?
Dihybrid cross given complete dominance of one allele over the other, in both loci, and otherwise complete independence of both loci so there is no linkage
Results of AaBB x AAbb
laws of segregation
The two alleles of each gene are packaged into separate gametes- they separate or move apart during gamete formation
Theory of Independent Assortment
Alleles for two different genes are randomly packaged into gametes with respect to one another
Multiple allele system
Gene for which three or more alleles persist in a population at relatively high frequency.
Human ABO blood typing
How gene combinations produce blood types
traits controlled by two or more genes
Ex. eye color, height, skin color
Role of the environment in influencing phenotype
-Alcohol: birth defects
-Nutrition as a child: height as an adult
-Temperature: Siamese cat color
How do dominant and recessive traits affect one another
Dominant + dominant= dominant
Dominant + recessive= dominant
Recessive + recessive= recessive
What is a linked gene?
The situation where two different genes are found on the same chromosome
What is the ratio of a dihybrid cross with linked genes?
How is sex determined in humans?
The sex chromosomes determine whether you are female (XX) or male (XY)
How are sex-linked genes inheritance patterns different than non-sex linked genes?
Non-sex linked genes show Mendelian inheritance pattern but sex-linked genes show criss cross inheritance
Sex-linked trait is often controlled by gene present only on X chromosome, hence no corresponding allele is present on the Y chromosome
How do the inheritance patterns differ between males and females for these disorders?
X-linked dominant: females are more frequently affected because all daughters and no sons of an affected father will be affected (Rickets)
X-linked recessive: males are more frequently affected (hemophilia A, red-green colorblindness)
Autosomal dominant: each affected person usually has an affected parent (Huntington's disease)
Autosomal recessive: both parents of an affected person are carriers (sickle-cell anemia, cystic fibrosis)
controlled by a single gene and unaffected by environmental conditions
Ex. Skin color, eye color
autosomal dominant disorders
Huntington disease and achondroplasia
Appear in every generation
autosomal recessive disorders
Tay-Sachs, Cystic fibrosis, sickle cell anemia, phenylketonuria