Genetics Flashcards
Gene
a section on a chromosome that is blocked by the presence of a dominant factor.
Allel
the different forms of a gene
genotype
the alleles for all the genes on a organism’s chromosome; controls an organism’s phenotype.
Phenotype
how a trait physically appears or is expressed
Heterozygous
a genotype in which the two alleles of a gene are different.
Homozygous
a genotype in which the two alleles of a gene are the same.
Codominance
an inheritance pattern in which both alleles can be observed in a phenotype.
Incomplete Dominance
an inheritance pattern in which an offspring’s phenotype is a combination of the parent’s phenotype.
Multiple Allele Inheritance
occurs when there are more than two different alleles of a gene for a particular trait.
Polygenic Inheritance
an inheritance pattern in which multiple genes determine the phenotype of a trait.
Pedigree
a diagram that shows the occurrence of a genetic trait in several generations of a family.
Who is the father of genetics? What plants did he study the traits of.
Gregor Mendel and he used pea plants.
What determines the phenotype of organisms?
Genotype (genes, alleles)
Describe a Punnett Square we use to make genetic predictions.
Punnett Square is a tool used to predict the possible genotypes for the offspring of 2 known parents.
What are the chances that a man heterozygous for freckles and a woman without freckles would have a child with freckles?
50%
What is the difference between phenotype and genotype?
Phenotype is the trait or the physical appearance while genotype is the genes for the alleles. (Genetics/DNA)
What is multiple allele inheritance and give a trait example?
When 2 or more alleles contribute to the phenotype. Ex) Blood type
What is polygenic inheritance and give a trait example?
Traits that control 2 or more genes. Ex) Human height, eye, skin color
List the guidelines for a dominant pedigree chart.
- Affected individuals have at least one affected parent
- The trait generally appears in every generation.
- 2 unaffected parents only have unaffected offspring.
List the guidelines for a recessive pedigree.
- Affected individuals have at least 1 affected parent
- Trait is not seen in every generation
- There are carriers (unaffected, heterozygous individuals) present.
A blue parrot (BB) is crossed with a red parrot (bb)
100% Blue
A heterozygous green frog is crossed with a pure bred green frog recessive.
100% Green
A heterozygous brown-eyed dog is crossed with a blue-eyed dog.
50% Brown
50% Blue
2 heterozygous red apples (green is recessive) are crossed.
75% Red
25% Green
